Vol. 18, No.1, March 21, 2003

In this Issue
Start up for 2003 publishing season
Tips for using this web site
Landscape and nursery
Emerald ash borer: Early detection is important
What can homeowners do to protect their trees from the emerald ash borer?
Early spring disease control
New resources for the nursery and landscape industry
2002 Perennial Evaluation Trials Online
Turfgrass
Spring into turf!
Christmas trees and forestry
Christmas Tree Insect Forecast Table
Other news
Weather news

Start up for 2003 publishing season

Joy N. Landis, editor

Welcome to the first issue of the growing season for Michigan State University's Landscape Alert newsletter. The articles in this issue offer updated information for making early season decisions.

Also, for those of you who use the Internet, our newsletters from the past five years are searchable for a wide range of topics at: http://www.ipm.msu.edu/land-cat.htm

Next issue: April 4.

Tips for using this web site

Joy N. Landis, editor

Our goal for the web version of the Alert newsletters is to provide you with quality, timely information that downloads easily. Here is an explanation of the links offered on the navigational bar at the top of each issue.

1) The "precipitation totals" link brings up statewide weekly precipitation totals from MSU's Agricultural Meteorologist Jeff Andresen.

2) "Growing degree days" takes you to GDD totals from the previous day as reported by various stations around Michigan to MSU.

3) "Evapotranspiration estimates" links to a map of Michigan where color indicates the previous day's estimated amount of evapotranspiration. Andresen provides this with his colleagues at the University of Wisconsin. The data will be posted regularly soon this spring.

4) Click on "Print or view text only" if you would like to view text without any graphics. Those with slower modem connections may find this the most effective way to view or print the newsletter.

5) Following the link labeled "MSU Diagnostic Services" will take you to the homepage of MSU's Diagnostic Services. The website includes directions for submitting a sample, how to contact the lab, and a library of articles and photos of common diagnoses.

"Landscape Alert home" links back to the calendar page of our issues where you can also search the newsletter archives or sign up to receive an email each time we post a new issue. You may also want to surf our other IPM resources at: http://www.ipm.msu.edu/scoutingIPM.htm

Hotlinks in our articles will appear in orange links. Links may lead to photos, tables, diagrams, email addresses or other websites. Clicking on the narrow black and white bars that separate the articles will return you to the top of the web page.

If you have questions or suggestions about reading the newsletters on the web, please feel free to email us at catalert@msue.msu.edu

Emerald ash borer: Early detection is important

Dave Roberts,
MSUE Southeast Region

Last summer and fall, we received numerous inquiries regarding treatments of trees and specifically which trees might be saved. Because it was difficult to keep up with these numerous inquiries, I developed a "Stages of Decline" for guiding the public on my web site (web1.msue.msu.edu/reg_se/roberts). These stages ranged from Stage 1, virtually healthy, to Stage 5, virtually dead. At that time, many of us believed that trees exhibiting decline up to Stage 3, representing 40 to 50 percent decline or canopy loss, could be saved by insecticide treatments. Because of results from last summer/fall treatments, we now believe that trees beyond 10 to 20 percent decline (probably) cannot be saved. This is due to rapid tree decline and the fact that there is generally far more tunneling beneath the bark by emerald ash borer (EAB) larvae than is visible in crown dieback. This extensive tunneling and disruption to the cambial tissues (those that transport water and nutrient) undoubtedly impedes the translocation of chemical treatments.

Preventative treatments and early detection
Two questions that ash owners need to ask themselves if they would like to save their ashes are: 1) can my tree(s) be saved? (Is it sufficiently healthy to be saved?), and 2) if my tree can be saved, am I willing to invest in treatments year after year for many years to ensure survival. Remember, we are not certain at this time that treatments will be sufficiently efficacious to save ash trees from the EAB. Many studies are planned for the coming season and we will keep you apprised of the results. Recommendations for treatments that might be effective are summarized on my web site.

 Of utmost importance, if trees are to be saved, treatments need to be applied as preventative applications (before infestation) to healthy trees or as "curative" applications (after infestation) to trees exhibiting no more than 10 to 20 percent canopy loss. We suspect that the less the infestation, the greater the chances of saving particular trees.

Those who hesitates may lose their ash
Another important factor in these determinations is to realize that trees advance from healthy to beyond salvage very quickly. In some cases during 2002, trees were rated and advanced in decline by as much as 30 to 40 percent in just a couple months. Hence, many trees would have passed from salvageable to beyond salvage very quickly. The most rapid decline, whether noticeable or not, would occur during the larval feeding period from July through the fall. Still, trees that may have appeared OK last fall may be beyond salvage this spring.

Woodpeckers as early detectors
One of my observations during the winter of 2001-02, even before the insect was identified as the emerald ash borer and as the culprit of the ash decline in SE Michigan, was that many affected trees were being visited regularly by woodpeckers, primarily the downy and hairy woodpeckers. I could simply drive down streets and determine which trees were infested and which trees were in an advanced state of decline. This woodpecker activity is summarized with photographs on my web site. Please consider that these birds will not necessarily visit all EAB-infested ashes.

During this past winter, I again correlated intense woodpecker activity with declining trees. In a number of instances, the EAB had moved into new neighborhoods last summer and the first sign of their presence was woodpecker activity this winter. Remember, EAB adults deposit eggs and larvae develop and cause severe damage during one season -- the adults do not emerge and create the telltale D-shaped exit hole until the following year. Hence, external symptoms in trees often lag behind extensive, internal damage performed by "invisible" larvae (no exit holes). The woodpecker's activity may actually be the first sign of EAB infestations, telling us that those particular trees or neighborhoods are in trouble long before severe dieback and decline symptoms in the ash trees. Coupled with the fact that decline may advance very quickly, woodpeckers alert us to strongly consider NOW what we should be doing this coming spring. Like PANIC!!!!

Professional arborists and landscapers, as well as homeowners, need to heed these early signs, remember the rapid decline of EAB-infested ash and plan for early spring treatments if the saving/salvage of valuable ashes is a desired outcome. My web site has been recently updated with current recommendations, new information and photographs.

What can homeowners do to protect their trees from the emerald ash borer?

David Smitley and Deborah McCullough
Entomology

Homeowners want to know if they can treat their ash trees themselves to protect them from the emerald ash borer. First, homeowners need to make sure they have ash trees and not some other type of tree. Only ash trees will be attacked. Second, insecticide treatments are not likely to help dying trees with extensive dieback. Insecticides will probably work best as preventive treatments to healthy ash trees. Finally, there is no need to treat ash trees unless you live in one of the infested counties: Wayne, Oakland, Macomb, Livingston, Washtenaw and Monroe. Protecting ash trees may be a good idea if you are located where emerald ash borer adults can fly to your trees. Any ash trees within a half to one mile of a known infestation are at risk next year. If you live anywhere in an infested county, it is likely that emerald ash borer will become a problem sometime in the next three years, if it isn't already. Unfortunately, emerald ash borer will be costly. Paying an arborist to treat your trees or treating them yourselves will be expensive, and so is the cost of removing dead trees. At this time, most of the infested ash trees are dying one to three years after dead branches are first found. Remember, if you decide to treat your ash trees with insecticide, they will need treating each year.

Spring treatments
Insecticides applied in the spring will probably work best on trees with little or no borer damage. We do not yet know if trees already damaged by borers will benefit from insecticide treatments in the spring, or at what point trees are too damaged to recover. It is unlikely that systemic insecticides applied as trunk injections, soil drenches or soil injections will move very well in trees with extensive tunneling injury. Trees with more than 20 percent canopy dieback usually have extensive damage that will be difficult to overcome, even if the trees are protected from further attack by trunk and foliage sprays. We will be conducting more tests this spring and summer to see how well (1) trunk injections in the spring, (2) soil injections in spring, and (3) trunk and foliage sprays in spring and early summer, work.

We will be testing the same kind of strategies used for a closely related insect, the bronze birch borer. We will treat ash trees with:

1)    A soil-injected, or soil-drenched systemic insecticide, over the root system in April (imidacloprid)
2)    Systemic insecticides injected into the trunk in May or June (imidacloprid and bidrin), or
3)    Contact insecticides sprayed over the foliage, trunks and limbs on June 1 and July 1 to protect trees from the adult beetles that we expect will be active from late May to early August (cyfluthrin, bifenthrin, carbaryl or acephate). Adult emergence information will be reported weekly in spring issues of the Landscape CAT Alert (order at: http://www.ipm.msu.edu/land-cat.htm).

Arborists and landscapers usually do a much better job of treating trees (especially large trees) with insecticide than homeowners do, and homeowners cannot make trunk injections of imidacloprid or bidrin on their own. However, if a homeowner prefers to make insecticide treatments themselves, they can purchase most of the insecticides listed above as the products in Table 1.

Imidacloprid should be applied to the root zone of ash trees in April because it takes some time to be absorbed by the roots and moved up to the foliage. The label says, "translocation delay can take up to 60 days." For emerald ash borer, we want the imidacloprid to be there in the soil in late April when the tree starts to move water and nutrients up to the branches. Imidacloprid drenches can be applied by spraying the insecticide over the tree roots in the area inside the tree canopy drip-line. Bayer recommends that you apply most of the spray within ten feet of the trunk. Then water the insecticide into the soil immediately after spraying by running a lawn sprinkler long enough so that a can or bucket fills to a height of one inch. We have also been asked about what happens if a homeowner uses Bayer Advanced Lawn Season-long Grub Control (imidacloprid) or the new Grub-Ex containing imidacloprid (last year the Grub-Ex active ingredient was halfenozide) on their lawn, including under ash trees, for grubs. These products are not labeled for tree and shrub pests and will not work well for borers when applied for grubs because the area under your ash tree will only receive about 1/10 of the amount needed for borer control.

Trunk and foliage sprays can be applied to small trees with hand-pump sprayers, or garden-hose spray attachments. Wear gloves, long pants, a long sleeve shirt, shoes and socks when applying any insecticide. Avoid getting spray mist on your skin or breathing it. Be sure to follow all label directions and do not mix insecticides at concentrations higher than the rate on the label.

Cultural practices and sanitation
Ash trees in areas where the borer is active should be watered during dry spells to avoid drought stress. Also, the removal of infested trees is desirable if it is feasible. Next spring, adult emerald ash borers will be emerging from infested trees. The removal of infested trees this winter and early spring before the adults emerge will help reduce the population. Trees must be chipped to pieces less than one inch long, de-barked, or burned to prevent beetles from emerging. Just cutting the trees and stacking the logs as firewood will not kill the beetles. If trees are going to be removed, cutting and chipping them before May 1 is desirable to prevent adults from emerging. Cut ash logs and branches can be taken to one of the marshalling yards listed below for disposal at no cost.

Resources:
USDA Forest Service: www.na.fs.fed.us/spfo/eab/index.html
Michigan Department of Agriculture: www.michigan.gov/mda
Michigan State University: web1.msue.msu.edu/reg_se/roberts/ash/index.html

Table 1. Homeowner products for the insecticides mentioned in this bulletin.

Marshalling yards
The following locations are now open for business to receive ash tree materials for disposal at no cost to the parties delivering the wood. There are a total of four locations available with their hours included. Additional sites will be shared as they come on line. The MDA website will be updated with this information as well.

Mid Michigan Recycling
24935 21 Mile Road
Macomb, MI 48042
Hours: Mon - Fri 8 to 5

Asplundh Tree Expert Co, Plymouth Industries Yard
13101 Eckles Road
Plymouth, MI 48170
Hours: Mon - Fri 8 to 5

City of Pontiac Sanitation Division
575 Collier Road
Pontiac, MI 48326
Hours: Mon - Fri 9 to 4

City of Westland
Department of Public Service
37137 Marquette
Westland MI 48185
Hours: Mon - Fri 7 to 5  

Early spring disease control

Dave Roberts
MSUE Southeast Region

Early spring is the time to consider and implement, if desired, various management procedures for tree and shrub diseases. In many if not most cases, diseases begin their dirty work in the early spring. During these nice rainy warm days in March and April, over-wintering fungal structures are maturing in such a manner that spores will be released to infect our plants as the new foliage begins to emerge. These disease organisms may establish themselves in susceptible plant tissue long before we realize they are present. In fact, the first sign that they may have infected our plants is when spots develop on the leaves.

Multi-cycle diseases typically repeat their spore development and release cycles several times during the season. In theory, stopping the first infection of these multi-cycle diseases will drastically reduce the buildup of the disease organisms on plants over the course of the season. Slowing the buildup of these multi-cyclic diseases generally results in less foliage damage and loss toward the end of the season. So, for example, crabapple trees may hold their leaves long into late summer and fall, resulting in better customer satisfaction and more appealing or aesthetically pleasing landscape plants.and perhaps less harm to plants if certain diseases are life threatening.

Monocyclic diseases may also attack plants in the early spring under similar environmental conditions that favor multi-cyclic diseases. With monocyclic diseases however, there may be only one stage of attack or a very limited period of attack. One example of a monocycle disease is the increasingly prominent tar spot of maple. The disease initially appears as small yellow spots on maple leaves -- these same spots enlarge through the season and eventually become dark.

Some of the more common diseases which begin their activity in the spring are scab, anthracnose of various trees and shrubs, tar spot of maple, Diplodia (Sphaeropsis) tip blight in pines and numerous leaf spots on numerous plants. For many of these diseases, spring management recommendations with fungicides often include applications at bud break and two or three repeat applications at three-week intervals. For more information and specific instructions on particular diseases, please consult pesticide labels.

New resources for the nursery and landscape industry

Diane Brown-Rytlewski,
Nursery & Landscape ICM Integrator

A Pocket IPM Scouting Guide for Woody Landscape Plants, Extension Bulletin E-2839
Price: $13.00/copy. Compiled and edited by Diane Brown-Rytlewski, Nursery and Landscape Integrator, Michigan State University IPM Program, Graphics design: Becca Thompson, Michigan State University IPM Program.

Just in case you've gotten bored this winter and have missed your favorite insect pests and diseases, the first scouting guide for woody ornamentals in the series of pocket guides developed by the IPM Program is now available. You can view sample pages at: http://www.ipm.msu.edu/LandscapePocket.htm

This 120-page guide is intended as a field supplement to standard references. The plastic-coated scouting guide with its 3.5" X 6.0" pages is designed to fit in your pocket for easy field use. With color pictures and descriptions, it will help you identify common pests and their damage, beneficial insects, common diseases, injury caused by deer, voles and rabbits, and abiotic plant injury. Guidelines for scouting and management are included in the guide.

Orders can be Faxed or mailed to:
MSU Bulletin Office: 10-B Agriculture Hall
Michigan State University, East Lansing, MI 48824-1039
Fax: 517-353-7168

You may also order by phone with a credit card by calling the Bulletin Office at: 517-355-0240. Checks should be made payable to Michigan State University.

Nursery and Landscape Research Projects and Educational Programs 2002
A summary of MSU research projects and educational programs for 2002 is available on-line at:
http://www.cips.msu.edu/landscape

Research topics include: plant evaluation; nursery production; landscapes and landscape management; insect biology and management; plant diseases and disease management; weed management; marketing; and educational programs. The document can be downloaded in whole or in part as PDF files.

2002 Perennial Evaluation Trials Online

Diane Brown-Rytlewski
Nursery & Landscape ICM Integrator

The MSU perennial trials were started in 1996 in response to growing interest in perennials. Evaluations of some of the newest hybrids are done, and trials last for two years. This year's evaluations consist of 43 taxa of perennials grown in the Horticultural Demonstration Gardens by Horticulturist Ann Hancock. Included on the web page are color photos of 19 of the evaluation trial plants. Quality of leaf/foliage, plant vigor, flower uniformity, strength of bloom and stalk and bloom display are evaluated. Also included are: date of bloom, insect and disease evaluations, notes on hardiness, and weather data. It is available on-line at: http://www.cips.msu.edu/landscape/P_eval.htm

For more information about the Horticulture Demonstration Gardens where the perennial trials take place, visit the MSU Horticulture Department Garden website at: http://www.hrt.msu.edu/gardens/manual.htm

Spring into turf!

Kevin Frank
Crop & Soil Sciences

As I peer out across the MSU landscape, the predominant color is still brown but with temperatures climbing into the upper 60's today, its hard not to envision some mowers frolicking on the turf and producing the subtle aroma of fresh cut grass. Although the temperatures are bouncing up and down this time of year, at least it appears that spring is starting to take a foothold, and we can start thinking about what to do to the turf.

Early spring activities
Although spring has finally sprung, don't get too eager to get out there and apply either your first fertilizer application or a preemergence herbicide application. We'd like to see that turf growing a little before we rush to apply, so hold your horses. Remember that the environmental signal for applying a preemergence herbicide (i.e. crabgrass preventer products) is when the forsythia bush is in full bloom. You can also use a soil thermometer to check soil temperatures. Apply preemergence herbicides when soil temperatures at a two-inch depth reach 50°F. In Michigan, the time for applications is usually around April 15 - ugh tax day!

I think it's a fair guess to say that not too many people are going to be mowing the turf this weekend, so here's your chance to pry yourself away from the basketball games and do some mower maintenance. This is a great time to sharpen those blades, especially if you didn't sharpen them before putting the mower to bed last autumn. Sharp blades ensure a clean, precise cut and if you do it now the lines at the local hardware shop are likely to be shorter and you won't lose any opportunities to mow the lawn in the future.

Given that our next issue of this newsletter isn't for a couple weeks, I'll provide this insight into the first mowing event of the season. Past trials at MSU have indicated that lowering the mowing height for the first mowing event of the season will help remove dead tissue and facilitate soil warming which will help the turf get growing faster. Be advised though not to get carried away with this lowering the mowing height recommendation. At most I would drop it one inch from your normal mowing height, be careful we don't want to scalp the turf. For most dropping the height ½ inch will probably suffice to clean up debris on the lawn from the winter and get that turf going.

Dead or alive?
After the tough year we had last year and the harsh winter we're just emerging from, some folks may be wondering if their turf is alive. In the next couple of weeks you should start to see the turf grow, however if you're a little restless and you're not seeing any signs of life, you can do a simple test. Take a couple cores of turf from the site (soil included), place them in a pot on a sunny windowsill, and provide adequate water and see if the turf starts greening up and growing. If you don't see any signs of life shortly after moving it indoors you can probably conclude that the turf is dead and you need to get that seeder tuned up to do some renovation work. I don't really expect to see widespread areas of dead turf emerging from the winter, but with the severe drought from last summer and lack of rainfall in the autumn there are certainly areas of turf that we may not be completely confident survived.

Weather news

Tracy Aichele
Geography

Note to readers
Jeff Andresen is currently on sabbatical leave in Europe and will miss the first half of the upcoming Michigan growing season. He is scheduled to return in early July. In the mean time, Tracy Aichele of the Michigan Climatological Resources Program will be providing periodic weather updates for this column.

Cold, dry winter
Warmer weather greeted us this week as a persistent trough dissipated and a more variable, spring-like jet stream pattern arrived. Despite the recent warming, the December to February winter of 2002-2003 was the coldest since 1993-1994. Just as importantly, with an almost total absence of Gulf of Mexico-origin moisture (our main source of water vapor in the region), precipitation totals remained well below normal (generally 25-50 percent of normal), so the 2002-2003 winter will also go into the record books as one of the driest of the past century.

Snows in early to mid-March in the southern part of the Lower Peninsula were welcomed for the additional moisture (totaling about ½ inch across southern Lower Michigan), but longer term precipitation totals for October 15 to March 18 were 3 to 8 inches below normal in the Lower Peninsula with the greatest deficits in the northern and western Lower Peninsula, where precipitation was only about 25 percent of normal. The prolonged cold and lack of snow cover throughout much of the state led to a deep frost layer, but none of the Michigan Automated Weather Network (MAWN) stations recorded soil temperatures below 18°F for December 1, 2002, through March 15, 2003. While the frozen soils have prevented some melting snow and recent precipitation from soaking into the profile, the cold temperatures may ultimately result in lower overall disease and insect pressure following several mild winters and elevated growing season pest pressure.

Heading into the growing season, low soil moisture reserves could be a concern with dry conditions in Michigan forecasted to continue at least through May. The Lower Peninsula is currently characterized by NOAA's drought monitor as being under "moderate to severe drought" and the Upper Peninsula is characterized as "abnormally dry." In contrast to the precipitation pattern, the areas most severely affected are the northern and eastern parts of the Lower Peninsula with soil profile moisture in some areas at 50 percent of normal. Most areas of the Lower Peninsula have topsoil moisture rated at 50 percent or less of normal.

For the Upper Peninsula, soil profile moisture is about 10-15 percent less than normal, but topsoil moisture is about 30 percent less than normal. Most areas of the Corn Belt are also facing drought conditions, but the Western Corn Belt may receive limited relief in March.

Long range forecast
In the equatorial Pacific, sea surface temperatures continue to cool, and an end to El Nino and a return to near-normal conditions in the equatorial Pacific are forecast for April-October. This is reflected in the NOAA long-lead outlooks for the Great Lakes region, which call for lower than normal precipitation through May and an equal-odds scenario for the summer. Forecasters are divided on the long-lead outlooks in the equatorial Pacific with some models indicating a weak El Nino for late 2003 and others indicating the development of La Nina. All of this uncertainty translates into a series of very vague forecasts for late 2003 into early 2004.