Dave Smitley...In late May and June of this year several arborists from Ann Arbor and the western suburbs of Detroit reported seeing an usual number of Norway and sugar maples with some upper branches that were dead, wilting or had stunted leaves. The affected branches were usually scattered about the crown, among other relatively healthy branches. The branch dieback was usually observed on stressed street trees that were either old, growing in poor soil, or restricted by pavement.

[Read the rest of this article...]

Gerry Adams, Dept. Plant Pathology, MSU

MSU Diagnostic Services and several professors, campus arborists and others have had quite a struggle with diagnosing the cause of the many mysterious problems in maples that have appeared this year. Maples are not the only trees we are encountering with such problems though. Equally mysterious samples of damaged or dead spruce and oak have arrived for diagnosis.

[Read the rest of this article...]

Thomas Dudek...Hardening plants or providing dormancy requires many conditions to occur all at the same time within the plant. Nursery practices like fertilizer applications, irrigation, pruning and light levels all contribute to how successful plants will overwinter and avoid winter injury.

[Read the rest of this article...]

Dave Smitley...If you notice some of the leaves have been recently chewed on a dogwood tree, look closer for a powdery white, or a black, green and yellow caterpillar-like worm. It is the dogwood sawfly, a member of the Hymenoptera (bees, ants and wasps) that looks like a caterpillar. The young larvae are covered with a white powder, but after the final molt the larvae are a striking yellow and black like in the provided photo.

[Read the rest of this article...]

Dave Smitley...In many parts of the state, we are seeing an outbreak of Lecanium scale on hardwood trees. Many species of hardwoods are susceptible, but the most commonly infested tree types are oak, maple and honeylocust. The first clue in urban areas is sticky droplets on cars parked under infested trees. These tiny drops of honeydew produced by scale insects as a way to excrete excess sugar may become very hard and difficult to remove when they dry.

[Read the rest of this article...]

By Bert Cregg... For folks who like to troll the web for discussions on gardening, landscape, and nursery topics, there is a new blog. The Garden Professors was the brainchild of Jeff Gilman (University of Minnesota) and Linda Chalker-Scott (Washington State University).

[Read the rest of this article...]

By Dave Smitley... Data collected last week from our Adrian test site show that ash trees treated with TREE-äge trunk injections in June of 2006 at the 0.4 g ai/inch dbh rate (the Med-High rate on the product label) are still in excellent health (Table 1).

[Read the rest of this article...]

September 10 Turfgrass Diagnostic Walkabout
Join us and Trey Rogers, of MSU Crop and Soil Science, for a walk and learn workshop and tour of an area that illustrates a wide variety of lawn care practices and problems. Identify and diagnose problems as they exist in an urban setting. The focus of this tour will revolve around insect, disease, weed identification and management practices. Participants are encouraged to bring samples of your turfgrass concerns for group discussion. CEU's: 3-Pesticide (3B or 6).

[Read the rest of this article...]

By Annemiek Schilder and Mark Longstroth...As a long-established blueberry growing region, Michigan has had it share of virus diseases, such as shoestring, necrotic ringspot, leaf mottle, etc. Recently, two new blueberry viruses were found in Michigan. The diseases they cause are not new since they are present in other growing regions such as the Pacific Northwest, but they are new to Michigan. Fortunately, the infections appear localized and efforts are underway to eradicate them to protect the Michigan blueberry industry.

[Read the rest of this article...]

By Dave Smitley... Some arborists reported an unusual number of Norway and sugar maples with a few wilting branches or isolated branch dieback in June and early July this year.

[Read the rest of this article...]

By Erik Runkle... Landscapers, nurserymen, greenhouse growers and plant retailers are invited to participate in the MSU Garden Plant Showcase on Tuesday, August 4. This half-day program features unbiased comparisons of seeded and vegetative annuals in a landscaped setting and an educational program featuring speakers from the MSU Department of Horticulture.

[Read the rest of this article...]

By Dave Smitley...Guerin Wilkinson from Greenstreet Tree Care and Kay Sicheneder, City of Ann Arbor worker, have reported many cases of branch-wilting on Norway Maples and some sugar maples in Ann Arbor, Plymouth and Canton. Here is how they describe the symptoms:

[Read the rest of this article...]

By Dave Smitley...European chafer beetles were very active on warm evenings around dusk in Lansing this past week. Sometimes a few dead ones remained on the sidewalk the next morning. In Lansing, they will be gone soon because they only fly for about a three-week period.

[Read the rest of this article...]

By Rebecca Finneran...Join other landscape professionals on July 31 for a one-day conference at Calvin College in Grand Rapids hosted by the Association of Landscape Professionals and MSU Extension. 

[Read the rest of this article...]

By Thomas Dudek...A new resource is available to landscapers, nursery growers and grounds managers who work with herbaceous perennials and need to identify diseases that impact these plants. Diseases of Herbaceous Perennials by Mark Gleason, Margery Daughtrey, Ann Chase, Gary Moorman, and Daren Mueller is published by The American Phytopathological Society.

[Read the rest of this article...]

By Thomas Dudek... Understanding your nursery costs helps growers improve cost management and production efficiency. Accurate cost estimation helps growers set prices that enable you to recover costs and maintain profitability.

[Read the rest of this article...]

By Thomas Dudek... The month of June is here, and it’s time to start our summer nursery meetings schedule for 2009. This year we’ve changed the location and time for our grower discussions. 

[Read the rest of this article...]

By Dave Smitley... Nothing is wrong. Early June is when maple petiole borer larvae finish feeding in the petioles of maple leaves, causing the blackened, restricted petiole (leaf stems) to break and the leaf to fall. The stems usually break at a darkened area near the leaf blade. Usually infestations are limited to sugar maples and only about 25 percent to 30 percent or less of the leaves fall to the ground. While spectacular, the leaf drop has little effect on tree health.

[Read the rest of this article...]

By Dave Smitley... Don’t get too excited by all the holes in your tree leaves, because caterpillar feeding damage does not affect tree health until more than 30 percent of the tree canopy is removed, and 30 percent canopy loss means that 1/3 of every leaf has been eaten, or 1/3 of all the leaves are gone.

[Read the rest of this article...]

By Dave Smitley... haven’t seen much injury to honeylocust trees so far this year, but the next two weeks is when most of the feeding damage occurs. One foliar spray of a pyrethroid, Sevin, Orthene or a nicotinoid insecticide will stop the feeding damage. But remember, the damage will be over by July 1, and the trees will push out new leaves.

[Read the rest of this article...]

By Dave Smitley... We have some localized outbreaks of gypsy moth caterpillars in Kent County and a few other parts of the state. The caterpillar feeding damage will pick-up in June and peak in early July.

[Read the rest of this article...]

By Gerry Adams... The loss of many landscape trees in Michigan caused by the emerald ash borer, drought and urban decline problems has emphasized our need for more choices for replanting. The loss of the monocultures of American elms which once graced our streets, followed by loss of our Ash species begs the question; what next, locusts, maples?

[Read the rest of this article...]

By Bert Cregg... Alkaline soil conditions can result in chlorosis (yellowing) in many landscape trees and shrubs. Typically this situation is due to reduced uptake of key nutrient elements as soil pH increases. This commonly occurs with pin oak (reduced iron uptake) and red maples (reduced manganese uptake) and many conifer species.

[Read the rest of this article...]

By Terry McLean... Genesee is sponsoring a Landscape and Turf Diagnostic tour of the Applewood Estate in Flint, Thursday, July 16, from 6:00-8:00 PM. This hands-on workshop is meant for commercial pesticide applicators, landscape and nursery professionals, and anyone interested in improving their ability to diagnose landscape issues.

[Read the rest of this article...]

By Erik Runkle... The sixth annual Michigan Garden Plant Tour is right around the corner: August 3 to 14. Greenhouse growers, landscapers, plant retailers, breeders, nurserymen, and plant enthusiasts are invited to attend this two-week coordinated open house of young plant producers and Michigan State University (MSU).

[Read the rest of this article...]

By Bert Cregg... While the emerald ash borer continues to expand into new states (Kentucky was added to the list last week), emerald ash borer is old news here in Michigan, especially in the southeastern part of the state. Efforts to restore urban and community forest canopy lost to emerald ash borer will continue, however, for the foreseeable future.

[Read the rest of this article...]

By Raymond Cloyd... Adult spittlebugs are 6 to 8 mm long and black, brown or yellow with distinct red eyes. The adults may possess orange bands on the wings, depending on the species. Nymphs are cream-colored with brown heads and red eyes. Generally, spittlebugs don’t cause significant plant damage, although they may stipple leaves.

[Read the rest of this article...]

By Diane Brown-Rytlewski... This armored scale has two forms (lilac and apple) that attack numerous hosts, including ash, lilac, maple, willow, crabapple, linden, elm and others. It overwinters as eggs, which hatch in mid-May, when black cherry or blackhaw viburnum are in full bloom.

No honeydew is produced.

[Read the rest of this article...]

By Jan Byrne...

Pathogen: Myrothecium roridum.

Hosts: Lamium, Molucella, Rudbeckia and Salvia.

Symptoms: This disease causes leaf spots. Concentric rings may develop in the lesions. Raised, black sporodochia develop on diseased tissue. In high humidity, the sporodochia are encircled by a tuft of white growth.

[Read the rest of this article...]

By Diane Brown-Rytlewski...

Cause: Phomopsis juniperovora and Kabatina juniperi (fungi)

Hosts: Juniper and rarely arborvitae, cryptomeria and chamaecyparis are susceptible to infection by these fungi. Susceptibility varies widely among species and cultivars.

Symptoms: Both fungi produce similar symptoms; time of symptom appearance differs.

[Read the rest of this article...]

By Gerald Adams... MSU researchers are leading a study of the hardwood tree disease known as leaf scorch. The study includes a survey of the distribution and host range of the pathogen that causes bacterial leaf scorch. Pathologist Gerry Adams is coordinating the surveys of 11 states including the North Central states and the Plains states (Nebraska, Kansas, North and South Dakotas). Diagnosis of all samples collected is done in his laboratory.

[Read the rest of this article...]

By Gerald Adams...This year we are experiencing severe Dothistroma needle blight in several regions of the state. My experience is that such damage is seen only every 10 years on average. Austrian pine is the primary species in Michigan where we see this disease which usually turns the foliage of the lower half of the tree brown. Ponderosa and limber pines are also susceptible as is the rare Chinese pine P. bungiana.

[Read the rest of this article...]

By Andrea Buchholz... Did you ever want to begin a garden in your backyard, but lack the resources or know-how to get it started? Well, MSU Extension has the answer to some of your gardening questions with the new Michigan Gardening website (www.migarden.msu.edu). The site features “tip sheets” which are printable fact sheets on a variety of gardening topics.

[Read the rest of this article...]

By Jan Byrne...

Pathogen: Pseudomonas spp. and Xanthomonas spp.

Hosts include: Astilbe, Chrysanthemum, Delphinium, Echinacea, Heuchera,
Hypericum and Rudbeckia.

Symptoms: Disease symptoms include water-soaked lesions on foliage that darken with age. Lesions may be bordered by the leaf venation.

Spread: Bacteria on the plant surface are easily spread to nearby plants by splashing water from rain and irrigation. Asymptomatic plants can serve as a source of inoculum.

Management: Bacterial pathogens can survive and reproduce on the surface of asymptomatic plant tissues. Disease symptoms develop once the pathogen reaches high population levels on the plant surface. Sanitation is especially important. Workers should wash their hands after handling diseased plants. Foliage should not be handled when it is wet. Symptomatic plants should be destroyed. Avoid overhead irrigation or time irrigation to minimize leaf wetness. Succulent tissue is especially susceptible to infection. Most fungicides are not effective against bacteria. Copper-based products are helpful in limiting populations of surface-borne populations of bacterial pathogens.

Note: Identification information for more plant diseases is available in the field guide A Pocket Guide for IPM Scouting in Herbaceous Perennials. To order, call 517-353-6740.

[Read the rest of this article...]

As you know, we have changed the CAT Alert web format this season. With the changes come many new features. We have established an informal article rating systems with stars, which allow you, the reader, to rate each article’s usefulness. By selecting a five-star rating, the highest rating possible, you are essentially saying the article provided beneficial information or it was exceptionally good. When using our search engine, these stars can help readers select articles.

Another feature available is found below the article in the “Actions” menu. Here you can email an article to a friend; use the Permalink option for saving the link; “Kick” the article (the more you click this option, the better chance the article will stay on the homepage, it is another way to rate the article); Dzone an article (another Web 2.0 social media sharing option), or bookmark the article with del.icio.us (an online version of your bookmarks that use keywords).

We will continue to update you with changes to our web. If you have any questions or comments, please feel free to email us at catalert@msu.edu. – Andrea Buchholz, asst. editor

[Read the rest of this article...]

By Jan Byrne... Good spring weather always brings a flood of spruce samples and phone calls about dying spruce trees to the lab. The clients often have several spruce trees in varying stages of decline and are panic stricken, desperately searching for any easy fix to stop the “disease from killing other trees.” Two people I spoke with last week had done Internet searches and were fairly confident that their trees were being killed by Rhizosphaera, a fungal needlecast pathogen.

[Read the rest of this article...]

Under a pilot program, the U.S. Department of Agriculture has financial assistance available for private landowners to have an individualized forest management plan developed.

[Read the rest of this article...]

MSU Extension will be hosting two Backflow Prevention and Boom Sprayer Calibration workshop opportunities in St. John’s, Michigan and Gaylord, MI. For more information, contact the Montcalm Extension office at msue59@msu.edu. For the agenda and mail-in registration, click here (www.ipm.msu.edu/cat09land/5-8SprayerCalibrationWorkshop.pdf).

[Read the rest of this article...]

By Dave Smitley... On-going research tests at Michigan State University by Dave Smitley and Deb McCullough and at Ohio State University by D. Herms, on the long-term protection of ash trees from emerald ash borer have produced some new results that may be of interest to tree care professionals:

[Read the rest of this article...]

By David Smitley... Homeowners have the option of treating ash trees themselves to protect trees from emerald ash borer by using imidacloprid as a basal soil drench. Imidacloprid is available to homeowners at local garden centers as Bayer Advanced Tree and Shrub Insect Control, and more recently as some other products.

[Read the rest of this article...]

By Bert Cregg... Recently I was asked to comment about a rash of e-mails floating around cyber-space concerning the toxicity to dogs of mulch made from crushed cocoa bean hulls. Cocoa mulch is a by-product of cocoa production. The dark brown mulch is aesthetically and aromatically pleasing, giving the garden a rich, chocolately scent. Since theobromine, a naturally occurring compound in chocolate is toxic to dogs, the internet is now filled with cyber-legends of dogs eating cocoa mulch and keeling over dead.

[Read the rest of this article...]

Landscape trees are dying prematurely. In many cases, this is because the correct care is not given at the time of planting and throughout the tree’s life. To help remedy this issue, the United States Forest Service has created a Tree Owner’s Manual. Just like the manual that comes with automobiles and appliances, this booklet includes a parts diagram, instructions for installation, tips for troubleshooting, and more.

[Read the rest of this article...]

By Fred Warner... Have you ever approached another person in the spring on a cool, rainy day and facetiously said, “Nice day,” and heard them respond with “Yeah, nice day if you’re a duck?” Well, when I’m in that situation, being the nematode geek I am, I think to myself, nice day for stem nematodes.

[Read the rest of this article...]

By Bert Cregg... As I noted in the last Landscape Alert, we are seeing a lot of various forms of winter injury on conifers as we move into spring. This has prompted a lot of calls to county MSU Extension offices from homeowners asking when and how to prune their damaged evergreens.

[Read the rest of this article...]

By Fred Warner... Root-knot nematodes are important pathogens of herbaceous perennials. In Michigan, the most common species is the northern root-knot nematode, Meloidogyne hapla. Where most root-knot nematodes are subtropical or tropical in their distributions, M. hapla is often the dominant species in temperate areas.

[Read the rest of this article...]

By Fred Warner... Simply put, growers of greenhouse plants should take whatever steps necessary to avoid foliar nematodes. This is imperative because if plants become infested, there are virtually no effective control options. The best tactic is removal of plants from the greenhouse and their immediate disposal. This can result in thousands of dollars in losses of material.

[Read the rest of this article...]

By Bert Cregg... As the days get longer and warmer, it’s time to get out and about and look for evidence of winter injury to trees and shrubs in landscapes nurseries and Christmas tree plantations. As I’ve noted here before, winter injuries are among the most common form of environmental problems that we see in Michigan landscapes year in and year out.

[Read the rest of this article...]

By Thomas Dudek... Nursery growers, farmers, and others planning to increase their irrigation pumping capacities over 70 GPM or those planning to put in a new well or surface water withdrawal with a pumping capacity of over 70 GPM need to be aware of the new Michigan Water Withdrawal Tool.

[Read the rest of this article...]

By Thomas Dudek... The following information was obtained from the Floriculture Area of Expertise Team web site and should be of interest to retail garden centers, landscapers and grounds maintenance foreman in Michigan.

[Read the rest of this article...]

Bert Cregg...Our rapid shift from hot, dry weather around Labor Day, to the heavy rains of a week ago make forecasting Michigan’s fall color more dicey than usual. Many trees in the mid-Michigan area and other parts of the state were beginning to shed leaves in response to our hot Labor Day weekend and the dry weather that preceded it. Now that soil moisture has been replenished in many areas it should help the trees to hang onto their leaves and give a good fall show.

[Read the rest of this article...]

Dave Smitley...We have just finished compiling our ratings of ash trees in East Lansing and Adrian, Michigan where we have been treating large, 12 to 15 inch dbh, ash trees to protect them from emerald ash borer as part of a research test on several new products. The canopy ratings of test trees this summer marks the third year since the test began. The control trees at both sites have declined dramatically during the test, going from an initial rating of 10 percent in 2005 to 50 to 65 percent canopy thinning and dieback in 2008.

[Read the rest of this article...]

Jennie Stanger...The MSU Soil and Plant Nutrient Laboratory announced a price increase effective October 1. County Extension offices will receive a copy of the new schedule next week.

[Read the rest of this article...]

Bert Cregg...With football season in full swing and leaves about to turn color, we come to the sad realization that snow will be flying before too long. Landscape plants in Michigan face an array of environmental challenges, but it’s safe to say that winter is the toughest season for environmental, or abiotic, injuries. This is largely because there are so many different ways that winter conditions can injure plants.

[Read the rest of this article...]

Dave Smitley...Guerin Wilkinson of GreenStreet sent me an email saying that he is getting calls about Lecanium scale problems on honeylocust trees in Canton, Plymouth and Northville, Michigan. Last year we also had some reports from Troy. Populations of Lecanium scale naturally go in cycles and rarely cause any harm to landscape trees. However, the scale infestation sometimes becomes much worse when the trees are sprayed for other reasons (like the mosquito control program in Saginaw and Midland counties) because the insecticide kills predators and parasites that keep the scale insects under control, while the scales are resistant to the insecticides that has been sprayed for many years.

[Read the rest of this article...]

Dave Smitley...If you see lots of webbing covering the branch tips of some of the trees in your neighborhood, it's probably fall webworm. Walnut, hickory, ash, and crabapples are some of the favorite targets, but many other types of trees can also serve as an adequate food source. The small yellowish-gray webworm caterpillars hide in the webs during the day. Some trees have actually been defoliated from having a tent on nearly every branch.

[Read the rest of this article...]

Bert Cregg...
Editor’s note: This article was originally published in the September 9, 2005 issue of the Landscape Alert.

While many homeowners are diligent to keep their lawns watered and green, trees and shrubs often get ignored. Reducing stress to trees and shrubs this time of year is critical. As we go into the fall, trees are shifting internal resources and undergoing physiological changes that will enable them to withstand the rigors of the winter to come. If plants are subjected to severe stresses now, they will be more predisposed to various winter injuries. With this in mind, irrigating trees and shrubs should be on your list of landscape chores. Here are a few “Do’s and Don’ts” to bear in mind as you irrigate your landscape.

[Read the rest of this article...]

Jan Byrne and Raymond Cloyd...

Pathogen: Multiple including Erysiphe spp., and Microsphaera spp.

Hosts: Achillea, Aquilegia, Aster, Coreopsis, Clematis, Delphinium, Helianthus, Lupinus, Monarda, Phlox, Pulmonaria, Rudbeckia, Salvia, Scabiosa, Solidago, Sedum, Veronica and Viola.

[Read the rest of this article...]

The following article was written by Candace Pollock from Ohio State University based on research conducted by Dr. Hannah Mathers and has information that would be of interest to Michigan nursery and landscape professionals - Thomas Dudek ,MSU Extension Educator, Grand Haven, Michigan.

[Read the rest of this article...]

Steven Gower...Landscape professionals and homeowners may encounter some common weeds in landscape beds, gardens and driveways with a prostrate, mat-forming growth. Four of the most common low-growing, summer annual weeds include prostrate knotweed, prostrate pigweed, prostrate spurge and common purslane. While similar in habit, these plants have specific characteristics that aid in their identification (see below). Just as with any other pest, correct weed identification is the first step to creating an integrated weed management program.

[Read the rest of this article...]

Janna L. Beckerman...

Editor’s note: MSU plant pathologist Willie Kirk advises that he likes this publication for the way it promotes integrated pest management (IPM) and clearly states the limits of the products. Thanks to Purdue for its development.

Disease control on ornamentals is a significant problem for the homeowner, nursery and greenhouse grower, and the landscape professional.

[Read the rest of this article...]

Dave Smitley...In the last two to three years, webworms have been abundant throughout southern Michigan in late summer. Silky tents made by webworm caterpillars are beginning to appear now on the branch tips of walnut, hickory, ash, elm, crabapples and other types of trees. The small yellowish-gray webworm caterpillars hide in the webs during the day.

[Read the rest of this article...]

Dave Smitley...Japanese beetles are beginning to defoliate some types of trees, shrubs and flowers in southern Michigan. On linden trees the beetles feed most heavily on the tops of trees, turning the leaves into lace. They also feed on a wide range of other deciduous trees and shrubs, including roses, linden, sassafras, sycamore, pin oak, Norway maple, Japanese maple, pussy willow, birch, elm, canna lilies, raspberries, grapes, beans, Virginia creeper and flowering fruit trees.

[Read the rest of this article...]

Reprinted with permission from Branching Out, An IPM Newsletter for Trees and Shrubs, Vol 14, No.7 http://branchingout.cornell.edu/. This article was originally printed in the July 13, 2007 issue of the Landscape Alert.

Verticillium wilt (120,121) is caused by a soil-borne fungus, Verticillium dahliae that commonly attacks maples, especially Norway maple, as well as about 45 other woody plants in the Northeast. Verticillium does not affect yews and conifers. V. dahliae survives in the soil as clusters of thick-walled cells known as “microsclerotia.”

[Read the rest of this article...]

Thomas Dudek...MSU Extension Horticulture and Marketing Educator Thomas Dudek is planning to take a bus-load of Michigan nursery growers on a two-day trip to visit five nurseries in Lorain and Lake County, Ohio August 19 - 20.

[Read the rest of this article...]

Dave Smitley...The poplar and willow borer is a small (0.25-inch long) dark brown to black weevil with a distinct white patch at the tail-end of the elytra. The larvae of this weevil bore into the stems of many types of willows and poplars, with most of the damage being found in nurseries or in recently planted trees. This spring it seems that some batches of pussy willows sent to Michigan nurseries from nurseries in other states arrived heavily infested with this weevil.

[Read the rest of this article...]

Bert Cregg...As we noted in an earlier CAT alert (May 2, 2008), last winter was a season of heavy snowfall and therefore, also a year of heavy de-icing salt application. In fact, in many parts of the state salt usage was so heavy that salt was in short supply or completely unavailable by the end of the winter. Along with heavy de-icing salt application comes the potential for plant damage.

[Read the rest of this article...]

Bert Cregg...Southern and mid-Atlantic universities have put together a very useful website for nursery growers. Waternut.org is being developed as an on-line Knowledge Center for Water and Nutrient management and Conservation, for the Nursery and Greenhouse industries. This website is an excellent resource and teaching aid for growers.

[Read the rest of this article...]

Bert Cregg...Heavy rains from the recent round of storms left many nursery fields underwater in Ottawa County. In touring the area yesterday with MSUE educator Tom Dudek, it appears that flood damage to field grown nursery crops was relatively minor. We observed some flooding-related mortality in lilac stock plants at a nursery and some limber pine transplants that were washed out. Overall, however, most fields seem to be in good shape.

[Read the rest of this article...]

Genesee is sponsoring a Landscape and Turf Diagnostic tour of the Applewood Estate in Flint, Thursday, July 10 from 6:00-8:00PM. Cost for attending the workdshop is $15 per person before July 3 and $20 after July 4. Registration will be open until the class is filled (35 people maximum).

[Read the rest of this article...]

Steven Gower...Mossy stonecrop (sedum acre) is a small, fleshy plant that can become a very difficult-to-control weed once established in a lawn. Mossy stonecrop belongs to a family of succulent plants (crassulaceae) introduced as an ornamental for rock gardens because of its ability to grow in very coarse, sandy soils of poor fertility. Unfortunately, mossy stonecrop can infest lawns with similar characteristics, out-competing desirable lawn grasses to become a serious weed.

[Read the rest of this article...]

One of our readers requested a list of native plants to use for gardening. See MSU list with advice at: http://nativeplants.msu.edu/

Andrea Buchholz...The volcano mulch challenge ends this week with a submission from reader Brien Worrell. He could not resist sending us this photo of a poor tree buried by a 10 foot pile of mulch spotted in Novi, Michigan.

[Read the rest of this article...]

MSUE educator Duke Elsner captured videos of plants covered in frost this past week in Grand Traverse County.

[Read the rest of this article...]

You don't need to travel to the tropics to find endangered species; there are rare plants and animals found just minutes from Ann Arbor, Jackson and Kalamazoo. Retreating glaciers created a unique landscape in southern Michigan with prairies, oak savannas and prairie fen wetlands. Although these habitats have been altered by invasive species, human activity and suppression of natural fires, globally rare species and communities still exist in this stunning landscape.

[Read the rest of this article...]

Join us for a one-time opportunity to recycle your old plastic flower pots, tree and shrub containers, plastic trays and labels. Clean out your garage or garden shed and bring as many old flower pots and plastic trays, even plastic buckets that you can find.

[Read the rest of this article...]

Steven Gower...Herbicides can injure desirable, non-target plants in a variety of ways, including drift, volatilization, carryover, tank contamination, misapplication or simply accidental or intentional exposure. In addition to diagnosing plant pathogens, nematodes and insect-related pests, all plant samples submitted to MSU Diagnostic Services – the multi-disciplinary plant health and pest diagnostic facility on campus – are visually inspected for pesticide injury.

[Read the rest of this article...]

Joy Landis...In response to our volcano mulch challenge, Mark Oomkes of Oomkes Landscape Management sent us something even better – pictures of what volcano mulching can produce.

[Read the rest of this article...]

Thomas Dudek...Nursery growers who need some resources for identification of weeds that impact their production will find these two publications helpful. "Weeds of Container Nurseries in the United States" by Joseph C. Neal, North Carolina State University and Jeffrey F. Derr, Virginia Tech.

[Read the rest of this article...]

Joy Landis...Each year, Landscape Alert readers see our articles bemoaning the use of too much mulch mounded up around trees. As horticulturalist Bert Cregg puts it, mulch should be applied in a “doughnut” shape in the drip zone of trees and shrubs, not a “volcano.”

[Read the rest of this article...]

Rebecca Finneran...The Easter Bunny may not be so fondly remembered this spring as the snow piles melt away from our landscape trees and shrubs. Heavy and consistent snow cover is the perfect recipe for chewing damage by a variety of rodents, especially rabbits. The snow cover keeps rabbits from being able to forage what little green is available underneath and makes a natural ladder for climbing into the crown of shrubs like burning bush and others.

[Read the rest of this article...]

Bert Cregg...In the last Landscape Alert, I mentioned that “Will we have lot of winter injury?” is one of my least favorite questions to face each year. “Will we have a lot of cones in Fraser fir?” is another dreaded question. In this case, however, we have a little better basis for making an assessment.

[Read the rest of this article...]

Bert Cregg...As our landscapes slowly wake up from their winter slumber, we’ve been getting quite a few reports of plants suffering from apparent salt damage. Many parts of the state had record or near-record snowfall totals, which means road crews applied record or near-record amounts of de-icing salts. Where we live in Mid-Michigan most of our snow came in 2-4 inch increments, which meant the salt trucks were out like Chicago voters, early and often.

[Read the rest of this article...]

Rebecca Finneran...Have you ever taken time to consider how much waste you generate during the gardening season? It can be quite an eye-opener. If I measured every load of plastic including pots, flats and plant tags that I dump in our garbage each season, I shudder to think about my contribution to our local landfill.

[Read the rest of this article...]

Diane Brown-Rytlewski...When planting, look for the root flare, and plant the ball with the root flare level with the ground. The kousa dogwood in Photo 1 declined over a period of several years before it died.

[Read the rest of this article...]

Diane Brown-Rytlewski...It is normal for evergreens to lose their interior needles in the fall. Loss tends to be more pronounced during years with dry weather. It is not normal for needles to drop from the current year’s growth, or to drop in the spring or summer. Check for another cause such as salt injury, a disease problem, frost, or drought if this occurs.

The information is from A Pocket IPM Scouting Guide for Woody Landscape Plants. For ordering information, please visit: http://www.emdc.msue.msu.edu/ or call the MSU Bulletin Office at 517-353-6740 and ask for inventory number E2839.

[Read the rest of this article...]

Jan Byrne...
Hosts include: Aconitum, Anemone, Aquilegia, Arisaema, Aster, Campanula, Hemerocallis, Heuchera, Liatris, Lupinus and Monarda.

Several perennials are commonly affected by rust diseases. Each rust pathogen has its own relatively small host range. Disease management strategies are fairly similar for this group of pathogens.

[Read the rest of this article...]

Doug Landis...Two nasty invasive plants have been gaining an increasing foothold in Michigan recently. Black and pale swallow-wort are European members of the milkweed family that have proven to be among the most highly invasive plants in the northeastern United States. These perennial, twining herbaceous vines can cover large areas in both open and wooded habitats, eventually excluding native plants. They tend to become established in disturbed areas from which they can invade less disturbed sites nearby. While both species have been present in Michigan for some time, many people do not recognize them or know they are of concern.

[Read the rest of this article...]

Dave Smitley...Take a look at the burning bush hedge in front of a business office in Okemos, Michigan. The entire group of burning bush plants dropped all their leaves by the end of August.  What is the problem?

[Read the rest of this article...]

Dave Smitley...The following question to the Landscape Alert Team by email this week:

Dr. Cregg:  I am a resident of Troy, Michigan and have found that I have scale on my Locust and Sycamore trees.  I obtained your name through the MSU Extension. I have had 4 companies to the home who have confirmed that scale diagnosis and have proposed a variety of treatment.

[Read the rest of this article...]

Jan Byrne...

Pathogen: Pythium spp. (P. aphanidermatum,
P. debaryanum, P. ultimum, etc.).

Hosts include: Berberis, Calendula, Chrysanthemum, Delphinium, Dianthus, Gaillardia, Gypsophila, Lathyrus, Lavandula, Lilium, Lupinus, Pelar-gonium, Phlox, Salvia, Sempervivum and Viola.

Symptoms: Wilting, stunting, uneven plant growth, crown rot and plant death. Roots are discolored. The cortex may slough off, leaving the vascular cylinder.

[Read the rest of this article...]

Rebecca Finneran...Hot summer days in July and August mark the time of year that waterways, wetlands and ditches come alive with a blanket of purple.  Unknowing tourists and photographers capture exquisite sunset photos of this seemingly harmless and attractive plant while it graces the landscape with its sinister grip.

[Read the rest of this article...]

Dave Smitley...At an MSU Extension Field Day at BayPointe Golf Club on August 16, over 120 attendees had the opportunity to walk the golf course to observe ash trees of all sizes that have been treated each year with a basal soil drench of imidacloprid since 2004.

[Read the rest of this article...]

Rebecca Finneran...A great stir has been occurring in recent years about using native plants in our landscapes. Natives have many benefits including their low-input thriftiness and amazing adaptability. I am the first to grumble when my “foo-foo” exotic plants aren’t performing like they were supposed to. Not enough rain, too hot, too cold, you name it, there are many reasons why a plant that doesn’t originate here may not live up to its reputation.

[Read the rest of this article...]

Dean Krauskopf...My girls are convinced that the reason I’m loosing the hair on top of my head is my skull is becoming more dense as I get older. They actually say “hard-headed,” usually in a loud voice as they slam the door. So, the hair roots can’t grow and the hair dies. Those of you who know me understand that this is obviously a misdiagnosis, but it may apply to many situations in lawns and ornamental beds. Restricted root systems can cause symptoms such as slow growth, small leaves, disease susceptibility, insect attack, early senescence and dormancy. All of these symptoms can be explained by reduced water and nutrient uptake and the resulting plant stress.

[Read the rest of this article...]

Jan Byrne...Symptoms of tar spot are now becoming more evident on maple foliage. I am receiving samples and numerous phone calls from folks concerned and down right angry about this disease. Some are very relieved to hear that the disease does not generally cause significant harm to well established trees. One client in particular, who called in frustration, was not consoled by this fact, because his wife was complaining to him that it made the tree ugly. Tar spot certainly does affect the aesthetics of the affected maple tree.

[Read the rest of this article...]

Dennis Fulbright and Bert Cregg...An affliction to river birch trees (Betula nigra) growing in the landscape was noticed in Cheboygan and Emmet counties this summer. The trees appear to have what has been described by others, including John Ruter (Univeristy of Georgia), as mouse ear, squirrel ear, little leaf or leaf curl. His description of symptoms are similar to the ones now appearing, “The leaves are small, wrinkled, often darker green in color, commonly cupped and have necrotic margins. Interveinal chlorosis is generally lacking in symptomatic leaves. New growth also has severely shortened internodes which gives a witches-broom appearance.”

[Read the rest of this article...]

Steve Gower...
Poison ivy (Toxicodendron radicans (L.) Ktze.

Family: Anacardiaceae (Cashew family)

Life cycle: Perennial woody vine.

[Read the rest of this article...]

Dave Smitley...If you see lots of webbing covering the branch tips of some of the trees in your neighborhood, it's probably fall webworm. Walnut, hickory, ash and crabapples are some of the favorite targets, but many other types of trees can also serve as an adequate food source. The small yellowish-gray webworm caterpillars hide in the webs during the day.

[Read the rest of this article...]

Steve Gower...

Broadleaf plantain: Plantago major L.

Life cycle: Rosette-forming simple perennial.

Leaves: All leaves originate from a basal rosette. Cotyledons are long and spatula-shaped. Leaves are generally smooth and broadly to narrowly oval, with parallel veins and smooth to slightly wavy leaf margins. Leaf base tapers to a distinct petiole. Petioles are usually green but occasionally pale pink.

[Read the rest of this article...]

Steve Gower...

Buckhorn plantain: Plantago lanceolata L.

Life cycle: Rosette-forming simple perennial.

Leaves: All leaves originate from a basal rosette. Cotyledons are very narrow and grass-like. Leaves are narrow, linear and elongated with parallel veins and generally smooth leaf margins. Long hairs may be present at the leaf base.

[Read the rest of this article...]

Jan Byrne...

Pathogen: Entyloma polysporu.

Hosts: Aster, Echinacea, Gaillardia, Helianthus and Rudbeckia.

Symptoms: Round, white spots, up to one centimeter in diameter. Young lesions may create very faint spots. Over time, the spots turn brown and become necrotic.

[Read the rest of this article...]

Dean Krauskopf...Plants in many hanging baskets and containers are yellowing and slowing growth. This may be due to the recent high temperatures, but more likely it’s due to a lack of fertility. High temperatures and low humidity have increased watering frequency and nutrient leaching High temperatures also increase the rate of nutrient release from slow-release materials, so a product labeled for four months many only last three.

[Read the rest of this article...]

Tom Dudek and Dave Smitley...The warm, dry weather patterns that have continued across much of Michigan have caused some outbreaks of spider mites in both the landscape and nurseries. Plants that have been reported with infestations include: arborvitae, azalea, boxwood, burning bush, dwarf alberta spruce, hemlock, sunflower, spruce, serviceberry and viburnum just to name a few. Natural control keeps mites in check in the landscape.

[Read the rest of this article...]

Dave Smitley...
Barberry looper
The barberry looper is a colorful caterpillar (yellow bands on sides and reddish-brown on top) with only two pairs of prolegs used to “loop” or “inch” their way when they move. This caterpillar may have two or more generations during the summer, so it can be found any time from June to September.

[Read the rest of this article...]

Deborah G. McCullough...An exotic woodwasp, Sirex noctilio, was recently captured in a trap in Macomb County. The larvae of this insect feed in stressed, dying or recently pine trees. Sirex noctilio has been an important pest in pine plantations in Australia, New Zealand and some South American countries. It is native to Europe, Asia and North Africa, but was discovered in New York in 2005 and in Ontario in 2006. Like many other wood-boring insects, it probably came to North America in solid wood packing material and it was likely present for several years before it was discovered.

[Read the rest of this article...]

Reprinted with permission from Branching Out, An IPM Newsletter for Trees and Shrubs, Vol 14, No.7 http://branchingout.cornell.edu/

Verticillium wilt (120,121) is caused by a soil-borne fungus, Verticillium dahliae that commonly attacks maples, especially Norway maple, as well as about 45 other woody plants in the Northeast. Verticillium does not affect yews and conifers. V. dahliae survives in the soil as clusters of thick-walled cells known as “microsclerotia.” Microsclerotia are extremely resistant to drought and cold and can survive for a decade or more as dormant propagules just waiting for exudates from a suitable host to wake them up.

[Read the rest of this article...]

Raymond Cloyd and Dave Smitley...Grasshoppers have long hind legs that are adapted for jumping (view photos). They tend to feed during the day, creating large, ragged holes in plant leaves. High numbers of grasshoppers can cause extensive plant damage within a short period of time. They overwinter as eggs in the growing medium

[Read the rest of this article...]

Raymond Cloyd and Dave Smitley...Blister beetle adults are 19 mm long and elongated. They vary in color from black and blue to brown, with or without stripes (view photos). They possess a characteristic constricted neck. These beetles overwinter as larvae in the soil. Adults feed on flowers and leaves, creating small rounded or irregularly shaped holes.

[Read the rest of this article...]

Jan Byrne...

Pathogen: Impatiens necrotic spotted wilt virus (INSV). (view photos)

Hosts include: Ajuga, Aster, Bracteantha, Camp-anula, Delphinium, Dianthus, Digitalis, Echinacea, Gaillardia, Gaura, Heuchera, Hosta, Leucanthe-mum, Lobelia, Lysimachia, Monarda, Oenothera, Penstemon, Phlox, Platycodon, Primula, Salvia, Scabiosa, Sedum, Tradescantia and Veronica.

[Read the rest of this article...]

Jan Byrne...

Pathogen: Septoria spp. (view photos)

Hosts include: Artemisia, Baptisia, Campanula, Chrysanthemum, Coreopsis, Delphinium, Dianthus, Echinacea, Gaillardia, Heuchera, Lamium, Lathyrus, Lupinus, Lychnis, Monarda, Potentilla, Ratibida, Rudbeckia, Stachys, Veronica and Viola.

[Read the rest of this article...]

Steven Gower...Landscape professionals and homeowners may encounter some common weeds in landscape beds, gardens and driveways with a prostrate, mat-forming growth. Four of the most common low-growing, summer annual weeds include prostrate knotweed, prostrate pigweed, prostrate spurge and common purslane. While similar in habit, these plants have specific characteristics that aid in their identification (see below). Just as with any other pest, correct weed identification is the first step to creating an integrated weed management program.

[Read the rest of this article...]

Dave Smitley...If you have ash trees that you are protecting from emerald ash borer with insecticide treatments, be sure to water them during dry spells.

[Read the rest of this article...]

Steve Gower...

Perennial sowthistle: Sonchus arvensis L. (view photos)

Life cycle: Erect, patch-forming perennial.

Leaves: Seedling leaves initially develop from a basal rosette from a deep taproot. Lower leaves are alternate, blue-green, 4 to 12 inches long with two to five lobes with prickly teeth on each side, gradually becoming smaller toward the top with a clasping base. Leaves have a thickened midvein and exude a milky sap when damaged. Leaf midvein is not prickly underneath.

[Read the rest of this article...]

Steve Gower...

Mugwort: Artemisia vulgaris L. (view photos)

Life cycle: Clump-forming, rhizomatous perennial.

Leaves: Alternate, deeply lobed and divided leaves are dark green above and silvery white below. Leaves emit a strong, sagelike odor.

[Read the rest of this article...]

Dave Smitley...Japanese beetles are now active throughout most of southern Michigan. In areas that received above average rainfall last July and August, there will be a bumper crop of Japanese beetles this summer. That’s because above average rain allows better survival of the grubs in non-irrigated turf. 

[Read the rest of this article...]

Jan Byrne...

Pathogen: Rhizoctonia solani (view images).

[Read the rest of this article...]

Diane Brown-Rytlewski...

Rose chafer: Macrodactylus subspinosis (view images)

Hosts: Rose, flowering cherry, crabapple, hydrangea, elm, elder, wisteria and several herbaceous perennials. The larvae overwinter as grubs in the soil, pupate in early spring and emerge in June.

[Read the rest of this article...]

Raymond Cloyd...Iris borer larvae initially feed at the tops of plants, chewing holes in leaves and giving leaves a ragged appearance (view images). They eventually create dark-streaked areas that appear watery. Larvae migrate down the plant, and then mature larvae bore into leaves a few inches above the growing medium surface.

[Read the rest of this article...]

Raymond Cloyd...Feeding by tarnished plant bug adults and nymphs causes yellowing of terminal growth, which becomes twisted and distorted. In addition, leaves may appear ragged and discolored.

[Read the rest of this article...]

Jan Byrne...Downy mildew problems have been showing up on perennials (view images). The name downy mildew refers to a group of related fungal pathogens that cause similar symptoms on a wide variety of plants. Downy mildew is not the same as powdery mildew, do not confuse the two.

[Read the rest of this article...]

Steve Gower...It seems that every year we hear from homeowners having problems with recently spread mulch (view images). The problem is rapid desiccation of foliage of all plants in landscape beds and grass along these beds within a day or two of spreading the mulch. This problem has been termed toxic mulch, sour mulch or hot mulch.

[Read the rest of this article...]

Thomas A. Dudek...Dr. Mike Marshall, Department of Horticulture, MSU, weed science specialist and I will review MSU test plots showing eight different pre-emergent herbicides combinations for field-grown shade trees. Also, I will be sharing an update on shade tree nursery disease and insect problems.

[Read the rest of this article...]

Bert Cregg...The “dog days”of summer have come early to mid-Michigan this year. As warm and dry conditions continue, it’s important to keep an eye on trees and shrubs in the landscape and look for signs of stress. This is especially critical for plants that have recently (within the past year) been planted. Homeowners and landscapers should plan to water newly established trees and shrubs once a week in the absence of rainfall.

[Read the rest of this article...]

Dave Smitley...I know the honeylocust trees look real bad right now from honeylocust plant bug (see June 8, 2007 Landscape CAT Alert issue), but these scruffy-looking trees will recover quickly after the plant bugs disappear during the next two weeks.

[Read the rest of this article...]

Dave Smitley...A big storm front from June 8-10 brought in a load of armyworm moths into Michigan. Many locations along Lake Michigan, especially places with bright lights on at night, reported an abundance of light brown moths for several days after the storm. But nobody noticed them more than the fans at Comerica Park during two night games, including the game that Justin Verlander pitched a no-hitter. The problem came from the gulls more than the moths.

[Read the rest of this article...]

Dave Smitley...The bad news is that this past week the injury from honeylocust plant bug to honeylocust trees continued to grow more severe, causing substantial defoliation of trees (see photos). The good news is that the injury should draw to a close over the next two weeks, and trees will begin to recover and push out new leaves.

[Read the rest of this article...]

Dave Smitley...Cottony maple scale females are all puffed-up with white cottony egg masses now. The crawlers should begin to emerge in the next two weeks. Lecanium scale females have also produced eggs, which will be hatching soon. These two soft scale insects rarely reach populations dense enough to damage trees.

[Read the rest of this article...]

Dave Smitley...Emerald ashborer adult beetles were observed in many locations this week. Most of the research tests using imidacloprid as a basal soil drench, basal soil injection or trunk injection were done with applications being made in April, May or early June. So that insecticide would be present in trees during the period of adult feeding in June and early July, as well as when the larvae are feeding under the bark from July to October.

[Read the rest of this article...]

Diane Brown-Rytlewski...

Cause: Cytospora kunzei (fungus) (view photos)

Hosts: The primary host is Colorado (blue) spruce. Other spruces, Douglas-fir, balsam fir, red and white pines, hemlock and larch are infrequently attacked.

[Read the rest of this article...]

Diane Brown-Rytlewski...

Juniper scale: Carulaspis juniperi (view photos)

Hosts: Juniper, arborvitae and chamaecyparis. An infestation of this armored scale causes off-color foliage, yellowing and dieback of juniper needles. Severely infested junipers may have little to no new growth.

[Read the rest of this article...]

Dave Smitley...Juniper shrubs can be sprayed for juniper scale in the first two weeks after crawler emergence, which will be sometime in June for most people. Horticultural oils work very well for armored scales like juniper scale when they are applied as a crawler spray.

[Read the rest of this article...]

Willie Kirk, Tom Dudek and Jan Byrne...This year, the weather has been conducive for infection with the common plant pathogen Botrytis cinerea (view photos). In commercial nursery fields and shade houses, the practice of growing plants close together creates a humid environment, which is ideal for the development of botrytis blight. In the presence of inoculum, when conditions are favorable for development of Botrytis and the plant is susceptible, botrytis blight can occur. In hostas, immature lesions appear mostly as water-soaked spots that increase in diameter to become circular spots with dark halos around the outside. As the lesions mature and increase in size, rings can be seen within the lesions, which appear cinnamon to dark tan in color.

[Read the rest of this article...]

Jan Byrne...Several landscape professionals are reporting damage caused by fire blight. Fire blight is caused by Erwinia amylovora, a bacterial pathogen. The disease is best known for the severe damage it causes in fruit orchards, but several common landscape plants are also susceptible. Cotoneaster, flowering crabapple, flowering pear, hawthorn, photinia, pyracantha and mountain ash are all susceptible.
Blossoms are particularly susceptible to infection; infections initiated in the blossoms can move into the woody tissue, causing shoot damage.

[Read the rest of this article...]

Bert Cregg...We have received some reports of frost damage to conifers in mid-Michigan associated with a freeze in mid-May. At the MAWN weather station at the MSU Horticulture farm south of campus, we recorded a low temperature just below freezing (30.7ºF) on May 18. In some low areas or frost pockets, it is likely that temperatures dropped a couple degrees colder; just enough to cause problems for newly emerged spruce, fir and Douglas-fir shoots.

[Read the rest of this article...]

Thomas Dudek...Nursery growers should be aware that the strong winds that occurred on Thursday, June 7, will cause some sand blasting of plants in both container and field growing systems. This sand blasting will open up wounds where both bacterial and fungal diseases can enter the plants. Foliar pathogens such as leaf spots, like Alternaria and Septoria and bacterial pathogens like bacterial leaf spots, can be a concern following these winds. Tender newly emerging leaves can be severely tattered and deformed also.

[Read the rest of this article...]

Bert Cregg...Summertime thunderstorms can cause problems for trees in a variety of ways. High winds and soaking rains can cause major limbs or entire trees to fail. Thunderstorms can also damage trees by lightning strikes. Lightning tends to hit tall objects. (Contrary to the light never strikes twice myth, lightning usually strikes the Empire state building 20 times a year.) Lightning contains an incredible amount of energy – often hundreds of millions of volts. Damage from lightning can range from relatively minor to total devastation.

[Read the rest of this article...]

Dave Smitley...Early June is when maple petiole borer larvae finish feeding in the petioles of maple leaves, causing the blackened, restricted petiole (leaf stems) to break and the leaf to fall.  The stems usually break at a darkened area near the leaf blade. Usually, infestations are limited to sugar maples and only about 25 to 30 percent or less of the leaves fall to the ground. While spectacular, the leaf drop has little effect on tree health.

[Read the rest of this article...]

Dave Smitley...
Emerald ash borer treatment survey
Tree care professionals in Indiana, Ohio and Illinois would like to learn from the experiences of our professionals here in Michigan.  Dr. Deborah McCullough at MSU has joined efforts with Shawn Bernick at Rainbow Tree to put together an on-line survey to find out what has worked and what has not worked for protecting trees from emerald ash borer.

[Read the rest of this article...]

Dave Smitley
Entomology

Many honeylocust trees in the Lansing area have small brown and distorted leaves from plant bug feeding injury (view images). The best way to check for honeylocust plant bug is to rap a branch over white paper or cloth. If the tree is heavily infested, small green bugs will rain down on the paper and scurry off. When adults are present, they will fly when disturbed.

[Read the rest of this article...]

Steve Gower...

Virginia creeper: Parthenocissus quinquefolia (L.) Planch. (view images)

Life cycle: Perennial woody vine.

[Read the rest of this article...]

Steve Gower...

Common cottonwood: Populus deltoids Marshall (view images)

Life cycle: Fast-growing, weedy tree.

[Read the rest of this article...]

Raymond Cloyd...Leafhopper feeding causes stippling of plant leaves that is similar to damage caused by twospotted spider mite. (view image) Leafhopper feeding can result in leaf distortion, chlorosis, plant stunting, leaf curling, leaf yellowing and necrosis. Extensive feeding damage gives plants a scorched appearance.

[Read the rest of this article...]

Jan Byrne...

Pathogen: Aster yellows phytoplasm. (view images)

Hosts include: Anemone, Bellis, Campanula, Chrysanthemum, Coreopsis, Delphinium, Gaillardia, Rudbeckia, Salvia and Scabiosa.

[Read the rest of this article...]

Jan Byrne...Symptoms of aster yellows may be subtle and resemble those caused by other factors. (See separate article about scouting and identification in this issue.) In many situations with ornamentals, a definitive diagnosis is helpful and allows managers to make better disease management decisions. One of the services that the MSU Diagnostic Services lab offers is molecular based (PCR) testing for aster yellows.

[Read the rest of this article...]

Steven Gower...
Won’t you be my neighbor?
Last summer, a Montcalm County resident noticed several of his mature trees showing signs of decline. As the summer progressed, so did the injury on his maple, ash, oak, cottonwood and white pine trees. This resident had an ongoing dispute with his neighbor and was convinced this person was killing his trees.

[Read the rest of this article...]

Raymond Cloyd...Slugs are worm-like, legless organisms that are often referred to as snails without shells (View photo). They vary in length from 1 to 15 cm when full grown, depending on the species. Slugs prefer to reside in moist areas and are active at night. They leave a silvery slime trail, which is most noticeable on sunny days.

[Read the rest of this article...]

Steve Gower

Redstem filaree: Erodium cicutarium (L.) L’Hér. ex Ait. (View photos)

Life cycle: Prostrate, fernlike winter annual or biennial.

[Read the rest of this article...]

Steve Gower...

Mouseear chickweed: Cerastium fontanum ssp. vulgare (Hartman) Greuter & Burdet (View Photos)

Life cycle: Patch-forming perennial.

[Read the rest of this article...]

Bert Cregg...The topic of planting native trees in the landscape generates considerable, and often passionate, discussion. For today, we’ll leave aside the native versus exotic debate and consider some of the other reasons to select Michigan natives for the landscape.

[Read the rest of this article...]

Rebecca Finneran...West Michigan is not exactly the South African oasis that the genus Agapanthus requires to grow. Yet, what makes this plant so appealing that it is gradually making its way out of Victorian garden parlors and into our back yard? Could it be that the exotic, azure inflorescence conjures up images of Cleopatra reclining under a canopy while dipping her toes into the Nile? Well, I guess that’s stretching it.

[Read the rest of this article...]

David Smitley and Gary Parsons...Recently, many media stories have come out about brood XIII of the periodical cicada. Unfortunately, the media stories do not always give accurate information about where to expect the cicadas. Brood XIII, like most of the periodical cicadas, have a 17-year life cycle. 2007 is the next scheduled appearance of this brood. In the last emergence of brood XIII, cicadas were abundant in some woodlots in northern Illinois, southern Wisconsin, eastern Iowa, the northern edge of Indiana and in two or three counties in southwest Michigan

[Read the rest of this article...]