Christmas trees
Field crops
Fruit
Home and yard
Nursery and landscape
Turfgrass
Vegetable
Diagnostic Services
Soil/Plant Nutrient Lab
Enviro-weather
Regional IPM Center
Pesticide safety
Organic: New Ag Network
Invasive species
Sustainable ag & food systems
MSU ANR departments
MSU Extension
Site index
Contacts/permissions
Some trees have actually been defoliated from having a tent on nearly every branch. But in most cases, each tree has three to four tents. They look bad, but cause little harm to the trees. Tree health is not affected until more than 50 percent of the foliage is consumed, and even then, the trees usually come back just fine the following spring. Pruning-out infested branches is a good strategy if you can reach the branches. Spraying the foliage around tents with B.t., Sevin, Orthene or a pyrethroid insecticide will prevent further feeding injury, but the old tent will remain visible. We have many natural parasites and pathogens of fall webworm that will bring these infestations under control. Places with lots of fall webworm this year may not have much next year. Outbreaks usually last two to three years. |
|||||||||||
back to top  |
|||||||||||
| MSU Extension Field Day: Fighting Emerald Ash Borer The MSU Extension Emerald Ash Borer field day on August 16 highlights the successful protection of ash trees in southeastern Michigan with insecticide treatments such as imidacloprid basal drenches. This field day is an educational hands-on seminar that will illustrate ways insecticides can be used to treat emerald ash borer–infected ash trees, as well as prevent emerald ash borer infestations in healthy ash. Walk the golf course to see test results after four years of MSU field research on soil drench treatments and compare treated trees of all sizes with untreated control trees. Other insecticide treatments will be demonstrated and discussed. Afterwards, listen to university specialists and tree care professionals discuss what treatments and application methods are working in southeast Michigan and ways that these practices can be applied in your area. Date: August 16. Where: BayPointe Golf Club, 4001 Haggerty Road, West Bloomfield, Michigan. When: 8:30 AM registration, 9:00 AM start time, program ends at 1:30 PM, lunch included. Cost: $30 per person. Walk-on registration will be available starting at 8:30 AM at the BayPointe Club House.
|
|||||||||||
| back to top |
|||||||||||
| Scouting for weeds: poison ivy Poison ivy (Toxicodendron radicans (L.) Ktze. Family: Anacardiaceae (Cashew family) Life cycle: Perennial woody vine. Leaves: Alternate, compound with three shiny leaflets. Leaflet margins may be smooth, toothed or lobed. The side leaflets occur on very short stalks; the middle leaflet occurs on a much longer stalk. Leaves may turn bright red in the fall. Contact with any part of this plant can cause a reaction in sensitive people. Stems: Shrubby or climbing, woody vines are supported by aerial roots. Flowers and fruit: Small, inconspicuous, yellow to green flowers have five petals. Fruit are gray to white berries (drupes). Reproduction: Seeds, creeping roots and stems, which may root if in contact with the ground. Control: Mechanical control is generally not recommended due to the allergenic dermatitis of poison ivy. However, when growing on desirable plants, carefully cut the woody stems at the soil surface and treat with an herbicide. Poison ivy can be controlled with herbicides that contain triclopyr (Brush-B-Gon), 2,4-D, triclopyr plus 2,4-D ester (Crossbow), glyphosate (Roundup, others) or triclopyr plus glyphosate (Roundup Poison Ivy Killer). Repeated applications may be necessary.
|
|||||||||||
| back to top |
|||||||||||
| Problem with river birch noticed 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.” In 2003, this was apparently an important problem in nurseries of southern states. At that time, it was rarely seen in landscape trees. In fact, potted plants showing the symptoms of mouse ear generally grew out of the problem once they were removed from pots and planted in native soils. This summer, I have seen this problem on both older landscape trees (8 to 20-years in place; Photos 1, 2, and 3) and five gallon potted one-year-old nursery trees (Photos 4). In both landscape and potted trees, one, two or all three of the stems may be afflicted. There is evidence that some landscape trees have had the problem for more than three years. Stems appear to vary in severity of symptoms. Some stems may be completely overtaken by the problem or the stems may have only a few branches involved. One 19-year-in-place clump in the courtyard of a house in Cheboygan County showed moderate symptoms, while several other trees along the foundation of the house and in the back near a lake showed no symptoms. At another house nearby, most of the river birch showed moderate to severe symptoms. A survey of river birch at a local nursery in the mid-Michigan area indicated that many stems of the one-year-old plants in five-gallon pots had symptoms. As in the field, sometimes all the stems were involved but more often only a few branches on a couple of the stems showed symptoms. The pH of all soils tested from symptomatic plants was close to or above pH 7 and many were closer to pH 8. The potted nursery material had been treated with elemental sulfur to reduce the pH, and the pH of the potting medium at the surface was 5. However, just half way down the pot and at the bottom of the pots, the pH was above 7 indicating the sulfur was having little effect around the roots. In 2003, Ruter announced that treatment with nickel brought the potted stems back to normal growth, but that was not attempted with landscape-grown plants. Diseased plant materials have been sent to MSU Diagnostics Services and we will attempt to determine the cause of the problem. At this time, we believe it is too early and unwarranted to treat with nickel-based products.
|
|||||||||||
| back to top |
|||||||||||
| Maple tar spot 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. Tar spot gets it name from the shiny black, tar-looking lesions it creates on the leaves of several maple species. Several species of Rhytisma cause tar spot. Susceptible maples include Bigleaf, Mountain, Red, Rocky Mountain, Silver and Sugar. The maples do vary in their susceptibility to infection. Tissue is infected in the late spring and early summer after the leaves are fully expanded. Initially the infected tissue turns light green or yellowish green. At this stage, the disease can not be easily diagnosed. The pathogen grows slowly in culture; meanwhile more diagnostic symptoms will develop on the host. The diagnostic symptoms include the development of black, shiny, tar-like tissue on the surface of the foliage. Plant pathologist used to say that significant outbreaks of tar spot occurred infrequently, however, over the past few years this has not been the case. For reasons unknown, tar spot has become a yearly occurrence and with seemingly increased severity. Generally, severely infected trees are in moist, sheltered locations which allow the pathogen to easily survive the winter. This disease is usually a cosmetic problem and does not affect the long-term health of the tree. The recommended fungicide applications for tar spot are at bud break and twice thereafter at 7- to 14-day intervals. Once the tree has leafed out, applications are ineffective. Fungicides recommended for disease prevention include triadimefon, mancozeb or Junction. Reference: Sinclair, W. and Lyon, H. 2005 Diseases of Trees and Shrubs 2nd edition. Comstock Publishing Associates, Ithaca, NY.
|
|||||||||||
| back to top |
|||||||||||
| An under-diagnosed cause of turf and ornamental problems 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. Testing for restricted rooting areas (soil compaction) is easy and quick. I use a 0.375-inch steel rod about 4 feet long that I bought at a box store. It doesn’t take a lot of strength to push the rod into the soil (if it does, you know you’ve found a problem) and it’s easy to tell if you hit a rock. Make sure that you probe completely around the affected plant or area; many times I’ve found compaction on only one side. Also, probe well away from the plant: roots usually extend out for several times the diameter of the top. I just hope my daughters don’t read this article; might give them ideas that could be painful. |
|||||||||||
| back to top |
|||||||||||
| Going native 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. Local wildflower expert, Chery Tolley, owner of Sand Hill Farms in Rockford, says that once established in the landscape, native plants are rugged beauties that can not only out perform our exotic hybrids, but will duke it out with just about any weather Michigan has in store for them. For example, native grasses are not only beautiful, says Tolley, they have incredibly deep root systems that can sustain them through many days of drought. Sustainability What amazes me about some of the plants known to be native to prairie settings is their range of adaptability. Several years ago, a friend gave me a cup plant, which normally thrives in a rich moist soil, but is doing very well in my “droughty” sand. Tolley cited another example of dune grass, planted on heavy clay. It was doing fine. Michigan has such a mix of clay-based soils intermingled with gravelly sand. If you observe the natives, often they are happily growing in either setting. Tolley is one of a growing number of Michigan native plant producers who extol their virtues for use in today’s landscape. Since these plants have existed in our climate for ages, natives naturally adapt to feast or famine growing conditions that cultivated exotic plants often succumb to. “Beautiful in their own way, these plant are not necessarily known as the “drama queens” that we have come to expect from ornamental garden plants. However, they may surprise you,” she said. Rattlesnake Master has a unique thorny appearance, but its fragrance is as sweet as honey. For the most part, native plants have been introduced to consumers in the wildflower-prairie style. Traditional gardeners may find this appearance a bit too wild and rangy. What people don’t understand, says Tolley, is that you can intertwine native Michigan plants in colorful vignettes within your existing landscape. Tolley has interwoven stately natives like compass plant and cup plant with delicate daylilies and interesting shrubs. Asclepias (butterfly weed) is a colorful summer bloomer. When mixed with Baptesia (false indigo), not only is the bloom season extended but this combo is a nice substitute for a tidy garden shrub. Her entire garden is a mix of plants that naturally attracts hummingbirds, butterflies and later in the fall becomes a good food source for native prairie birds. Do your homework Tolley notes that in a rich fertile soil, adaptable natives can also become invasive. Her garden was completely taken over by a beautiful six-foot prairie plant known as Rosin weed in just three short years. Known for its cheerful yellow blooms that lead to heavy seed production, the birds love them. “I just bought one small plant!” she said. The next year there were a few more and the next year they were coming up everywhere and out competing the other plants. “Do your homework,” she says. With a little research, you should be able to come up with a great list of adaptable plants just right for your garden. Many counties have little known places to observe plantings of native plants. Two really neat places to visit in the West Michigan area to learn about natives are the Hudsonville Nature Center and Loda Lake Wild Flower Sanctuary in Newaygo County. Tolley says these are some of the best kept secrets for easy day trips. If you are interested in learning more on how to incorporate native plants into your shady woodland garden or a sunny landscape a class is being offered by the Kent MSU Extension Office entitled Landscaping with Native Plants, Saturday, August 18, 8:45 AM-4:30 PM. You can also download a brochure by going to www.stuckongardening.com and scrolling down the Master Naturalist section. The fee for the day-long event taught by a variety of professionals is $60.00. Contact Ginny Wanty at 616-336-3108 with questions and class availability. You can contact the Kent County MSU Extension office at 336-3265 for program information or log on to www.stuckongardening.com for classes, conferences and program information. Michigan State has additional resources on native plants because of their ability to bring in beneficial insects and pollinators. Read facts about individual plants and view which ones are the most successful when it comes to attracting insects and pollinators. Please visit http://nativeplants.msu.edu/ for more information. You can also find a list of Native Plant producers at http://www.mnppa.org/.
|
|||||||||||
| back to top |
|||||||||||
| Michigan Environmental Assurance Program The opportunity for nursery and greenhouse crop growers to become involved in the Michigan Environmental Assurance Program (MAEAP) is new. Growers who participate in the program and address the environmental risks identified in the confidential assessment can become environmentally assured or “MAEAP verified.” This environmental recognition can be another way to differentiate your business from others. Contact your local MSUE or Conservation District office to get started in the MAEAP process. |
|||||||||||
| back to top |
|||||||||||
| White grubs begin feasting on turf roots... last call for Merit, Arena, Meridian, GrubEx, and Season-Long grub control I am now seeing lots of small European chafer grubs feeding in lawns and golf course roughs. The grubs will be getting larger and eating more in September. Watch for grub damage to appear in late September and October, especially during dry periods when the turf is stressed and wilting. Also, with the bumper crop of Japanese beetle adults this year, expect more grubs and more skunk and raccoon damage than usual. Merit, Meridian, Arena and homeowner products containing imidacloprid will still give adequate control of grubs if applied in the next week, but the level of control will begin to decrease when these products are applied after mid-August. The only other products labeled for control of grubs in the fall are Sevin and Dylox, which work fairly well when watered-in immediately after application with a 0.5 inch of irrigation. Use a granular formulation when treating areas that are not irrigated. Sevin and Dylox degrade quickly in soils with a high pH (> 7.5). |
|||||||||||
| back to top |
|||||||||||
| Managing stressed turf Recent rainfall across some areas of the state have provided some much needed relief to drought-stressed turf, but unless temperatures cool and rainfall becomes more reliable don’t expect non-irrigated turfgrass areas to spring back to life very quickly. We recorded 0.5 inch of precipitation at our research center on campus this week, but on non-irrigated plots this is hardly enough to make up for the deficit in soil moisture conditions that has accumulated over the last month. Keep in mind that not only the turfgrass has been stressed during the summer heat and drought, but weeds have not really been flourishing either. I’ve noticed that in non-irrigated rough areas on golf courses there is zero crabgrass pressure, but when you look at the rough areas on the edges of irrigation coverage the crabgrass is doing quite nicely. Just like the turf, the weeds need some water to really flourish. If you’ve been providing some irrigation or have been lucky to be under one of the rain showers, crabgrass or broadleaf weeds could be causing you to consider treatment options. Hard to believe, but we’re probably only a little more than a month from our first frost and with the first frost event, all of the warm season annual weeds such as crabgrass will check out for the season. Makes you wonder that if you spray for crabgrass now and then have to come back in a couple weeks for a second application to make sure you burned it all down, you’d be getting close to the date when Mother Nature will take care of the problem for you. For broadleaf weeds, remember that these weeds are definitely more challenging to kill during the summer heat than they will be in the autumn. Bottom line on the weeds is that if you can have a little patience, either Mother Nature will take care of them for you or an autumn herbicide application will clean up the broadleaf weeds for next season.
|
|||||||||||
| back to top |
|||||||||||
| Turfgrass Field Day August 22 The Michigan Turfgrass Field day is scheduled for August 22 at the Hancock Turfgrass Research Center on the campus of Michigan State University. There will be morning research tours focusing on golf turf management and commercial turf/athletic field management. In the afternoon, there will be in-depth workshops on diseases, weeds, athletic fields and turfgrass species. MDA pesticide recertification credits (category 3A) will be available for the morning and afternoon tours. On-line registration is available at www.michiganturfgrass.org or call Kay Patrick at 517-321-1660. |
|||||||||||
| back to top |
|||||||||||
| Hemaris moths gracing home gardens Pretty much every summer about this time, I get calls from folks who are very excited to report something they are seeing in the gardens that looks and behaves much like a hummingbird, except it can’t be a hummingbird because it has two antennae. Two species of sphinx moths known as the hummingbird clearwing, Hemaris thysbe and the snowberry clearwing, H. diffinis feed on nectar during the day much like a humming bird does. Both species occur throughout the eastern United States and are common in open woodlands, fields and gardens in Michigan. The snowberry clearwing is slightly smaller of the two and is considered more of a bumblebee mimic because of its yellowish body and dark wings. Snowberry larvae are reported to feed on honeysuckle, dogbane and buckbrush. Adults eat from many flowers, including thistles, milkweed and lilac. The hummingbird clearwing is reddish brown and has a wingspan of about 1.5 inches to 2.25 inches. Its larvae feed on honeysuckle, buckbrush, wild cherry and plum. Adults hover and sip nectar at many different flowers, including honeysuckle, beebalm, phlox, lilac and blueberry and milkweed. The hummingbird clearwing can be seen working on flowers on YouTube at: http://www.youtube.com/watch?v=QoppxSg7n30 See great photos of both species at: http://www.forestryimages.org/search/action.cfm?q=hemaris |
|||||||||||
| back to top |
|||||||||||
| Cicada killers set all time record and appear to be growing in size I believe the lab has received more cicada killer calls this year than in the previous five, possibly ten years combined. And they appear to be getting bigger. Several people who have called this past week described a giant wasp digging in their yards to be over three inches in length. This may be somewhat of an exaggeration, but I think the point is that these guys are really big and really scary wasps. Spider mites continue their reign as the number one landscape and garden pest, followed closely by Japanese beetles. If the leaves on your trees and shrubs are turning an off-color, then there is a good chance that spider mites are to blame. We had samples in the lab this week that had over 40 live mites with many more unhatched eggs on a single average size leaf. |
|||||||||||
| back to top |
|||||||||||
| Development of drought conditions in Michigan Scattered showers and thunderstorms brought some much needed rainfall to a few locations across Michigan during late July, but the rainfall was localized and drought conditions persist in many areas of the state. For the growing season thus far (beginning April 1), precipitation deficits have grown in many areas to the 3.0 to 5.0 plus inch range, although these figures are somewhat misleading since the majority of the drier than normal conditions have taken place since early June when crop water needs are relatively greater. Normal precipitation for this time frame is on the order of 11.5-13.0 inches. Precipitation totals across the state as estimated by National Weather Service radar are given in Figure 1 and illustrate the areas of greatest deficits including areas of southwestern and eastern Lower Michigan as well as the western Upper Peninsula where totals remained less than 25 percent of normal. In some areas of the state, July 2007 will go into the books as one of the five driest on record. Meteorologically, the dryness has been associated with a persistent upper air ridging feature anchored across western North America that has reduced the amount of low-level moisture flow (the “raw material” of precipitation) into the Great Lakes Region. As of the beginning of August, drought conditions were reported across sections of the Upper Midwest in Minnesota, Wisconsin and Michigan southward through the Ohio Valley into the southeastern United States. These patterns are illustrated in the most recent version of the Palmer Drought Severity Index (Figure 2), which depicts areas of long term precipitation surpluses and deficits. Note that some of the drought conditions in Michigan have now slipped into “Severe” and “Extreme”categories. As an example of the gradual depletion of soil moisture, volumetric soil moisture at a 10-inch depth under grass taken from the MAWN automated weather station at East Lansing is plotted versus time and with daily precipitation totals in Figure 3. The soil at the site is capac loam. Soil moisture can be seen to decrease from a value of approximately 0.25 inches³/inches³ following the rainfall of early June to about 0.10 inches³/inches³, then peak once again in late June following a 1.3 inches rainfall event before falling to its end of July level of approximately 0.08 inches³/inches³, which is near the soil=s wilting point.
|
|||||||||||
| back to top |
|||||||||||
| Weather news Showers and thunderstorms brought more rainfall to many areas across southern Lower Michigan during the last few days, while central and northern sections of the state were largely missed. Overall, drought conditions continue to be a major problem in many areas of the state. In the short term, forecast guidance does not suggest any major changes to the current and recent past weather upper air pattern, although given a bit more west to east or zonal jet stream flow, there will be relatively more frequent chances for precipitation than in recent weeks. Early this weekend, high pressure will be in control of the weather across the Great Lakes region, with fair, warm, and dry weather expected through Saturday. A frontal system approaching from the northwest will bring the chance for showers and thunderstorms to northern sections of the state by late Saturday evening and over the remainder of the state on Sunday. Given limited low‑level moisture ahead of the front, any precipitation is expected to be scattered in nature, with many areas remaining dry. For a change, best chances for rain with this system will be across western and central sections of Upper Michigan. Dry weather is expected again Monday statewide, with another chance for scattered showers statewide on Tuesday in association with an upper air disturbance moving across the region. Temperatures during the next several days will remain at above normal levels, with highs ranging from the upper 70's far north to near 90ºF south and lows from the upper 50's north to mid‑ and upper 60's south through Sunday. In the medium range time frame, there is some sign of change, with the persistent upper air ridge over western and central sections of the lower 48 states projected to move (at least temporarily) to the east. As a result, the 6‑10 day outlook, covering August 14‑18, calls for near normal temperatures and for precipitation to increase to above normal levels statewide. In the 8‑14 day time frame, covering August 16‑22, the outlook calls for mean temperatures to increase back to above normal levels statewide, with precipitation totals expected to range from near normal levels across southern sections of the state to above normal levels in the north. |
|||||||||||
| back to top |
Email the web developer.