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Lead Editor: Curtis Young

Contributing Authors: Pam Bennett, Joe Boggs, Cindy Meyer, Jim Chatfield, Erik Draper Dave Dyke, Gary Gao, Tim Malinich, Bridget Meiring, Amy Stone and Curtis Young

Buckeye Yard and Garden onLine provides timely information about Ohio growing conditions, pest, disease, and cultural problems. Updated weekly between April and October, this information is useful for those who are managing a commercial nursery, garden center, or landscape business or someone who just wants to keep their yard looking good all summer.

BYGL June 2, 2011

Thursday, 02 June 2011 17:25

This is the 9th 2011 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension Educators, Specialists, and other contributors in Ohio.

In This Issue:

1. PLANTS OF THE WEEK: Annual (Impatiens); Perennial (Baptisia); Woody (Black Locust); Vegetable (Eggplant); and Weed (Wild Parsnip). 2. HORT SHORTS: Growing Degree Days (GDD); What Happended to my Daggone Strawberries?; Kudzu…in Ohio?; and From Plant to Plate - Simple Gardens, Simple Recipes, Simply Good. 3. BUG BYTES: Bagworm Egg Hatch; Honeylocust Horrors (Honeylocust Pod and Honeylocust Plant Bugs); Ailanthus Wonders (Ailanthus Webworm); and Thistle Tortoise Beetle Taking Down Thistle. 4. DISEASE DIGEST: Vascular Wilts of Landscape Trees and Download Vegetable Disease Diagnostic Posters. 5. TURF TIPS: Black Cutworm Update; What are Those Reddish Threads in my Lawn? (Red Thread); and Black Medic Blooming in Turf. 6. INDUSTRY INSIGHTS: Potato Leafhoppers have Returned. 7. WEATHERWATCH. 8. COMING ATTRACTIONS: School Integrated Pest Management Seminars Scheduled. 9. BYGLOSOPHY.

APPENDIX - ADDITIONAL WEBSITE RESOURCES.

1. PLANTS OF THE WEEK. *ANNUAL - IMPATIENS - (Impatiens walleriana).

Now that the weather is finally cooperating, gardeners are planting lots of impatiens in shade gardens around Ohio! This easy-to-grow shade-lover does best in well-drained soils and in shade ranging from light to heavy. The more sun these plants get, the more water required to keep them healthy. Most of the newer cultivars don't require pinching to make them bushy or deadheading (removing the dead blossoms). Plants grow anywhere from 6" (pixie varieties) to 12-15" tall. Flower colors are red, pink, orange, salmon, white, purple, and bi-color. The newer double cultivars are loaded with blooms compared to varieties from the past! Impatiens are relatively pest-free; however, it is a good idea to rotate them out of a flower bed every few years to avoid the potential for Verticillium wilt.

For more information, see:

Missouri Botanical Garden Kemper Center for Home Gardening information on Impatiens walleriana Clemson Cooperative Extension Home and Garden Information Center on Impatiens

*PERENNIAL - BAPTISIA, FALSE INDIGO (Baptisia spp.).

This durable, long-lived North American native perennial likes to be planted and left alone! Therefore, select a sunny site that has normal Midwest soil and give this plant a permanent home. Plants grow to around 2 1/2-3/1/2' tall and around 3-4' wide in a rounded mound, depending upon the variety or cultivar. It is relatively pest-free and has great heat and drought tolerance. Blue false indigo also has great foliage that appears bluish-green. The lupine-like flowers appear on spikes in late May and early June. The seed pods that develop are also quite attractive and last into the fall. The seed pods can be used in dried arrangements. If the plants are grown in light-shade or fertile soil, they tend to get tall and floppy.

Many breeding programs around the country have introduced new cultivars with great features, including 'Purple Smoke'. This was discovered at the North Carolina Botanical Garden, Chapel Hill by curator Rob Gardner. It is a hybrid of B. australis and B. alba and is loaded with smoky violet flowers on charcoal gray flower stems; it has smaller leaflets than B. australis and gets around 2-3' tall.

For more information, see:

University of Kentucky Plant information on Baptisia australis Missouri Botanical Garden Kemper Center for Home Gardening information on Baptisia australis var. minor

*WOODY - BLACK LOCUST (Robinia pseudoacacia).

Michael A. Dirr writes in the "Manual of Woody Landscape Plants" that, "Europeans have grown, appreciated and selected superior forms of this tree while Americans treated it as some pedestrian weed." While many may think this way, there are some great qualities to this plant. This tree is a common sight in many natural growing areas and is a suitable candidate for even the toughest of growing conditions. While it may not be suitable for the home landscape or as a specimen tree it could be considered a tree for highway or reclaimed stripped- mined areas. It is currently blooming in the northern part of Ohio and has a white, fragrant, pendulous flower. Individual flowers have the typical look of a legume or bean family member to which it belongs, and creates a great spectacle mid to late May into June. This tree averages 30-50' in height and 20- 30' in width. It does have a few problems including locust borer, leaf spots and powdery mildews.

For more information, see:

Ohio Department of Natural Resources - Ohio Trees Guide

*VEGETABLE - EGGPLANT (Solanum melongena).

The eggplant is a native of India and a relative of tomato, potato and pepper. It can be started early indoors, but most gardeners set out transplants from the garden center. Space plants 18" apart with 2-3' between rows. To properly rotate crops, do not plant in the same space occupied by tomato, potato or pepper the previous two years. Eggplants love heat. With proper irrigation they will continue to develop and produce fruit throughout the summer.

Use a complete fertilizer at planting and make a second application after the first harvest.

The most common problem with eggplant are flea beetles which eat tiny holes in the leaves. Too small to hand pick, the beetles are easily controlled with insecticides labeled for use in the vegetable garden. Use pruning shears to harvest the fruit. The stems are tough; twisting and pulling to harvest will only damage the plant. Plan on harvesting when the fruit is still small, about 6-8", and the skin is shiny. Over mature fruit with dull skin and a spongy interior should be discarded. 'Black Beauty' is a standard color and shape. 'Ichiban' is long and thin, and 'Casper' a white-fruited variety.

For more information, see:

OSUE FactSheet on Growing Eggplant in the Home Garden

*WEED - WILD PARSNIP (Pastinaca sativa).

As a member of the carrot family, wild parsnip is a biennial. It spends the first year growing vegetatively then blooms the following year. Individual flowers are borne on a compound umbel atop of the 2-5' tall plant. Leaves are large, up to 18" long, and oddly pinnate. The actual flowers are about 1/8" across and have tiny yellow petals. The blooming period may last 2 months from late spring until mid-summer. Flattened, winged seeds are spread by wind to produce the next generation of wild parsnip.

Wild parsnip is one of the weeds commonly mistaken for GIANT HOGWEED (Heracleum mantegazzianum). However, giant hogweed is much larger, up to 15' tall, and has white flowers and a very thick reddish purple, spotted stem.

For more information, see:

Wildflowers of Illinois - Wild Parsnip

2. HORT SHORTS. A. GROWING DEGREE DAYS (GDD).

GDD is a measure of the daily maximum and minimum temperature and directly relates to growth and development of plants and insects. The GDD of any zip code location in Ohio is estimated using the GDD of ten OARDC weather stations and available on the web at: http://www.oardc.ohio-state.edu/gdd/ .

The range of GDD accumulations in Ohio from north to south is 421 to 841. Following is a report of GDD for several locations around Ohio as of June 1, 2011: Painesville, 421; Cleveland, 462; Toledo, 537; Canfield, 525; Findlay, 558; Van Wert, 575; Wooster, 613; Coshocton, 704; Columbus, 823; Springfield, 763; Dayton, 766; Cincinnati, 803; Ironton, 810; Portsmouth, 813; and Piketon, 841.

To put these GDD accumulations into perspective, the following is an abbreviated listing of plant and insect species with their respective phenological event and average GDD accumulations at which these events occur. Due to variations in weather, temperature, humidity, etc., these events may occur a few days earlier or later than predicted by the average GDD. By looking at a city, town, or village nearby on the above list, or visiting the above website, one can see what is taking place in the landscape.

Black cherry, full bloom, 419; Miss Kim Manchurian lilac, first bloom, 422; locust leafminer, adult emergence, 437; doublefile viburnum, full bloom, 444; black locust, first bloom, 467; common ninebark, first bloom, 478; oystershell scale, egg hatch, 497; smokebush, first bloom, 501; arrowwood viburnum, first bloom, 534; American yellowwood, first bloom, 546; bronze birch borer, adult emergence, 547; black locust, full bloom, 548; American holly, first bloom, 556; mountain laurel, first bloom, 565; potato leafhopper, adult arrival, 568; juniper scale, egg hatch, 571; common ninebark, full bloom, 596; American yellowwood, full bloom, 599; arrowwood viburnum, full bloom, 621; multiflora rose, full bloom, 643; northern catalpa, first bloom, 675; black vine weevil, first leaf notching due to adult feeding, 677; Washington hawthorn, full bloom, 731; calico scale, egg hatch, 748; greater peach tree borer, adult emergence, 775; rhododendron borer, adult emergence, 815; northern catalpa, full bloom, 816; mountain laurel, full bloom, 822; dogwood borer, adult emergence, 830; oakleaf hydrangea, first bloom, 835; and cottony maple scale, egg hatch, 851.

For more information, see:

Growing Degree Days and Phenology for Ohio Understanding and Using Degree-Days

B. WHAT HAPPENDED TO MY DAGGONE STRAWBERRIES?

That's the question that Julie Crook, OSUE Horticulture Program Coordinator, Hamilton County, was asking herself as she tried for days to find out what critter and/or person was responsible for the continuing disappearance of the beautiful strawberries from her lovingly tended strawberry patch. Was it neighborhood kids? Racoons? Turtles? Foxes? While all certainly have been known to consume strawberries, Julie only had to keep an eye on a member of her own family to identify the berry thief, her own daggone golden doodle, Bentley.

She should have known, since she also reported that last year the enterprising mutt was apprehended eating her tomatoes! It seems that the doggone doodle apparently thought the nice round tomatoes were balls and being part golden retriever, proceeded to try to play with them. Of course, once he found they tasted good, Bentley was hooked on the big red round fruity balls (driven by his French poodle heritage?). Perhaps he thought that Julie had lost her green thumb and was now producing some kind of stunted, rough textured, oddly shaped tomatoes. At any rate, Julie was reminded of what all should remember, fruit is attractive to a wide variety of pests and without adequate protection they will often get more of it than the grower.

C. KUDZU…IN OHIO?

Stephanie Downs, Invasive Species Forester for the Ohio Division of Forestry recently authored an article that appeared in the 2011 Spring/Summer Ohio Woodlands, Water, and Wildlife Newsletter. With her approval, we are including the article in this week's BYGL. While out in the field, if one happens to notice kudzu growing, please contact Stephanie by email or telephone. Her contact information is included at the end of the article.

When most people think about kudzu, Georgia comes to mind…or Alabama…or some other southern state…not Ohio. We can't have kudzu this far north, right? Unfortunately, kudzu is already here, we're just not sure how much. While known locations of kudzu throughout the state have been documented for the past few years, we still don't know the extent of this species here in Ohio. Knowing how to identify it, and knowing how much of it we have, is the first step to figuring out how to keep it under control.

Kudzu is a vine that is native to Asia. It was introduced to the United States in the late 1800s for erosion control, feed for livestock, and landscaping. While it historically has been a major problem in the southern United States where the winters are warmer, kudzu is surviving in Ohio and seems to be doing quite well in some locations. This is a species that poses many threats to our Ohio woodlands. Kudzu has been shown to have very rapid growth rates, and can take over large areas relatively quickly. This vine will grow over anything it encounters, including trees, killing them over time. Once established in an area, it is very difficult to control. Early detection and removal is the best method for getting rid of it.

This invasive plant contradicts the old saying "Leaves of three, let it be." It has tri-part leaves (like poison ivy), but unlike poison ivy, leaving it be is not a good option. Each of the three leaflets is three to seven inches long and will often have lobes. Flowers are generally present from June to September, and are two to 12 inch bright purple clusters similar to pea flowers. The fruit is present from September to January, and consists of flat, tan, hairy seed pods up to three inches long.

Gardeners, landscapers and nature enthusiasts can help ODNR control kudzu in Ohio before it becomes as big of a problem as it is in the South! If one sees this plant in a yard, woods, neighborhood park, local hiking trail, or anywhere else in the state, please contact ODNR. If one knows of a location with kudzu, contact Stephanie Downs, Invasive Species Forester for the Ohio Division of Forestry by email at: [email protected] or by phone at: (740)774-1596.

D. FROM PLANT TO PLATE - SIMPLE GARDENS, SIMPLE RECIPES, SIMPLY GOOD.

From Plant to Plate (FPTP), a program from the Lucas County Ohio State University Extension, introduces basic edible (vegetable) gardening techniques for the backyard, community, or container gardener. The resources feature plants in salad gardens, salsa gardens, and garnish gardens. The program follows the life of some easy, economical, edible plants from start to finish, meaning from seed or transplant, through the growing season to harvest, washing, preserving, and preparing simple, tasty, healthy recipes. This program is designed to inform and inspire gardeners of all skill levels, as well as tempt the taste buds!

FPTP offers a website compiling information like OSU Extension FactSheets on vegetable gardening topics, and food preservation; brochures with information on vegetables such as lettuce, spinach, radishes, tomatoes, peppers, tomatillos, easy-to-grow herbs, and simple tasty recipes featuring fresh garden vegetables. Master Gardener Volunteers and Extension staff are able to access a train-the-trainer lesson and educational displays for use at community programs.

For more information, see:

FPTP Website

3. BUG BYTES.

A. BAGWORM EGG HATCH.

Joe Boggs reported that overwintered eggs of the COMMON BAGWORM (Thyridopteryx ephemeraeformis) have hatched in southwest Ohio and Dave Shetlar noted that recent hot temperatures have probably induced egg hatch in the central part of the state. Joe observed silk strands dangling from last season's female bags as well as 1st instar bagworms widely distributed on infested host plants. A percentage of the tiny 1st instar caterpillars will produce a strand of silk upon hatching from eggs. The silk catches the wind to transport the caterpillars to new locations. This method of distribution is known as "ballooning" and it is one of the reasons bagworms often appear on hosts that were not infested last season.

It is a common misconception that bagworms only eat evergreens; in fact, the caterpillars can feed on over 130 different species of plants including a wide range of deciduous trees and shrubs. Indeed, deciduous trees and shrubs are sometimes overlooked during bagworm inspections allowing the plants to become reservoirs for reinfestation of neighboring evergreens.

The 1st instar bagworm caterpillars carry their bags held upward making them look like tiny dunce caps. The 2nd instar bagworm caterpillars, as well as all the succeeding instars, carry their bags held downward like pine cones. Late instar bagworms can be highly destructive, particularly to evergreens. The best way to avoid damage is to target early instar caterpillars for control.

Early instar bagworms can be effectively controlled using the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) (e.g. Dipel, Thuricide, etc.). This is considered a biorational control method since the bacterium will not kill bio-allies such as predators and parasitoids. Once eggs begin to hatch, bagworm populations should be closely monitored since egg hatch can occur of an extended period of time. Btk is a stomach poison which means it must be consumed to kill the caterpillars, and its residual activity is very short-lived. Thus, two applications may be required. The efficacy of Btk declines once bags reach 3/4". University research has also shown that a soil drench application of dinotefuran (e.g. Safari) is also effective against early instar caterpillars. Likewise, this systemic insecticide will not affect beneficial insects.

For more information, see:

Purdue University, Department of Entomology Extension Fact Sheet

B. HONEYLOCUST HORRORS.

Joe also reported observing HONEYLOCUST POD GALLS produced under the direction of the midge fly (Dasineura gleditchiae) and the spotted, twisted foliage produced by the feeding activity of HONEYLOCUST PLANT BUGS (Diaphnocoris chlorionis). Both only occur on their namesake host; however, the handiwork of the plant bug is far more obvious and potentially damaging. As with most plant bugs, honeylocust plant bugs use their piercing-sucking mouthparts to inject enzymes into plant cells which dissolve the cell's contents. The bugs then feed on the resulting cell slurry. Affected leaves may appear stunted and twisted and the leaflets chlorotic, stippled, and deformed. The damage mimics and is sometimes mistaken for herbicide injury.

Honeylocust plant bug adults are emerald green and around 1/8" long; nymphs are obviously much smaller and yellowish-green. Both have excellent eyesight and will quickly dart away from probing fingers. The nymphs hatched from overwintered eggs and began feeding as soon as the leaves emerged from buds, thus damage commences very early in the spring. Most of the significant damage is produced by the nymphs since they feed throughout leaf expansion. Adults will soon begin to appear in southern Ohio and they will continue to feed for about one to two months before disappearing in mid- to late July. Since the nymphs are the most damaging stage, this means that most of the damage has already occurred for the year; however, it will remain evident throughout the season.

The tiny midge fly that produces the pod galls belongs to the gall-midge family Cecidomyiidae. The midge larvae (maggots) orchestrate gall development with each gall containing a single maggot. By exuding chemicals that mimic plant hormones, a maggot directs a newly expanding honeylocust leaflet to become a swollen, fleshy, seed-like structure that envelops the maggot. Thus, the maggot grows its own home (and restaurant!) with individual leaflets becoming a gall structure that shelters and feeds the maggot.

The galls are at first light green but they become rusty-red as they mature and numerous galls can present an unsightly appearance. Also, mature galls will drop from infested trees causing defoliation. The midge fly can have several generations per season and although galls can only form on newly expanding leaflets, new galls can develop with each flush of new growth. However, midge fly populations are seldom high enough to cause serious damage to the overall health of an infested honeylocust. Normally, the galls simply appear as one of nature's many oddities.

For more information, see:

Penn State University Entomology Fact Sheet Forest Pest Fact Sheet

C. AILANTHUS WONDERS.

Curtis Young reported that large numbers of AILANTHUS WEBWORM (Atteva aurea) moths are continuing to fly to his porch lights in western Ohio. Reports of plant pests generally solicit concerns; however, since the caterpillars of this ermine moth (Family Yponomeutidae) feed exclusively on the non-native, invasive TREE OF HEAVEN (Ailanthus altissima), Curtis' report generated delight, if not great hope!

The webworms produce communal nests by pulling leaflets into a network of loose webbing. Several caterpillars live within the nests consuming the leaflets bound by the webbing. The webworms can grow up to 1-1 1/2" long and they have a wide, light greenish brown stripe down their backs and several thin, alternating white and olive green stripes along their sides. The caterpillars are sparsely covered with short, erect hairs, which help to suspend them within the webbing. When disturbed, the caterpillars move backwards out of the nest and drop towards the ground on strands of silk.

Ailanthus webworms are native to tropical regions in Central and South America where the caterpillars feed on native trees in the genus Simarouba (family Simaroubaceae). The moth was originally assigned the scientific name, Atteva punctella, and it was known that the moth jumped from its native hosts to the non-native Tree of Heaven (Simaroubaceae). It was assumed the moths exploited the ever-expanding range of Tree of Heaven to move north into the U.S. and Canada. However, recent research involving DNA bar-coding, moth morphology, and food plant records revealed that while A. punctella and A. aurea co-inhabit tropical regions of the New World, the moth in the U.S. and Canada is A. aurea.

Ailanthus webworm moths are multivoltine meaning that there are several generations per year. The caterpillars are capable of defoliating their odoriferous namesake host and they may feed on stem tissue once all leaves are devoured. Unfortunately, such extreme damage is rare on large trees. Although feeding by this webworm has yet to halt the spread of tree of heaven, hope springs eternal since this is one of only a few insects known to infest this encroaching interloper.

D. THISTLE TORTOISE BEETLE TAKING DOWN THISTLE.

Joe Boggs reported observing significant injury to CANADA THISTLE (Cirsium arvense) caused by the THISTLE TORTOISE BEETLE (Cassida rubiginosa). Joe has watched a patch of Canada thistle progressively decline over several years in part due to the feeding activity of this beetle. Both the adults and larvae feed on the leaves of thistle as skeletonizers. Feeding scars are irregularly shaped ovals with one leaf epidermis still intact producing what looks like a window pane. Most feeding occurs on the upper leaf surface. The collective feeding activity of the adults and larvae reduces the photosynthetic area of the thistle. Feeding can be heavy enough to reduce or completely prevent the host plant from blooming and producing seed. Repeated defoliations over consecutive years may reduce the vitality of the thistle patch resulting in levels of biological control. The extent of the impact of the tortoise beetle is most likely dependent upon its population size. The beetle's impact can be increased by the presence of the THISTLE HEAD WEEVIL (Rhinocyllus conicus) that attacks the flower buds of thistle and a bacterium, Pseudomonas syringae pv. tagetis, that bleaches out the terminal growth of the thistle plant.

The tortoise beetle is native to Europe and northern Asia, and it was intentionally imported into North America as a biological control for thistle. The weed-whacking beetle is also known as the "thistle defoliating beetle" and it feeds on other non-native thistle nasties including musk (Carduus nutans) and plumeless (C. acanthoides) thistles.

Like other tortoise beetles, the adults have a body shaped like a flattened pith helmet. The beetles are pale green or yellowish-green which allows them to blend with its host's leaves. The head and legs of the adult are typically hidden under the flares of their helmet-like body and the antennae can be hidden or extended out from underneath the front of the beetle.

The oval-shaped larvae are grayish-green and have a ring of spines arranged crown-like around the edge of their bodies. The larvae also sport a pair of spike-like appendages (cerci) at the tip of their abdomen which are used to practice a bizarre behavior. They impale an odious collection of feces and shed exoskeletons with their cerci, and then they arch their abdomens upward to carry around their repugnant package umbrella-like over their bodies. They look like tiny, walking poo-balls. It is assumed this is a defense against predation.

For more information, see:

University of Utah Factsheet on Beneficial Insects: Beetles Biological Control of Thistle

4. DISEASE DIGEST. A. VASCULAR WILTS OF LANDSCAPE TREES. The C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) is already beginning to receive samples being checked and cultured for DUTCH ELM DISEASE (Ophiostoma ulmi), VERTICILLIUM WILT (Verticillium sp.), and OAK WILT (Ceratocystis fagacearum). The similarity of all of these diseases is that they are all vascular wilts, which means that the funguses that cause the disease grow and spread in the vascular tissue of the infected plant. These diseases usually cause a dark discoloration, or streaking symptom, under the bark of infected plants. These dark streaks are the fungus's clogging the vascular tissue so the tree cannot move water efficiently. Infected trees usually show symptoms in the upper canopy first by wilting, yellowing, and dieback of the current year leaves, leaves may also have a scorched appearance due to the lack of water.

Verticillium wilt is common on maples and other trees in the same family, such as red bud or smokebush. Verticillium has the widest host range of the three wilt diseases, infecting many food crops and herbaceous perennials too. This fungus survives in the soil for many years and waits for an infection opportunity on a susceptible host plant. The opportunity may come when plant roots are damaged or stressed. Dutch elm disease is a fungus spread by elm bark beetles (European and American) and through natural root grafting underground. This disease infects Ulmus species and was first found in the US in Cleveland, Ohio! Oak wilt usually infects red and black oaks and is spread by sap feeding beetles and root grafting, similar to Dutch elm disease. For more information on all of these wilt disease of landscape trees please refer to the Ohioline factsheets listed below.

The only way to confirm whether your tree has one of these wilt diseases is to check for symptoms and have it confirmed by culture at the CWEPPDC. To send a good sample, select 1/2-1" thick branches from recently wilted areas of the tree where streaking under the bark can be seen, or may be suspected. The branch sections should be 6-8" long or more. Send branch samples to the clinic, without adding any water, in a sturdy box along with a completely filled-out sample form. For more detailed instructions on sampling for wilt disease, check out the clinic website at http://ppdc.osu.edu . Once at the site, select "Submit Sample", then "Landscape", and "Wilt Diseases."

For more information, see:

Dutch Elm Disease Factsheet Veticillium Factsheet Oak Wilt Factsheet

B. DOWNLOAD VEGETABLE DISEASE DIAGNOSTIC POSTERS.

Vegetable diseases are popping up now and identifying them can be challenging. Dr. Sally Miller and the team in OSU/OARDC's Vegetable Pathology Laboratory have prepared posters of some of the common diseases with key signs and symptoms, including microscopic features. You can view and download these posters from the Vegetable Pathology Lab's web site: http://www.oardc.ohio-state.edu/sallymiller/Extension/index.htm#Diagnosticposters.

Posters include: bacterial streaming, botrytis grey mold, downy mildew of cucurbits, lettuce drop, phytophthora blight, powdery mildew of cucurbits, radish rhizoctonia root and hypocotyl rot, tomato late blight and septoria leaf spot.

Don't see a poster you would like to have? Send suggestions to Dr. Sally Miller at: [email protected] .

5. TURF TIPS. A. BLACK CUTWORM UPDATE.

Earlier this season, Dave Shetlar reported that high numbers of black cutworm (Agrotis ipsilon) moths were flying to his black light traps at night in central Ohio (BYGL 2011-06 (05/12/11). This week, Dave noted that he is now finding large numbers of caterpillars in turfgrass. The caterpillars range in size from nearly mature "snake size" down to 2nd and 3rd instars. Black cutworms spend the winter in the Gulf States; they are unable to survive the winter as pupae in the soil where temperatures of the top 1" of the soil drop below 25F. The adult moths are blown north each spring riding the wind currents of storm fronts. Dave suspects the wide ranging sizes of the caterpillars indicate multiple introductions of moths into Ohio due to the numerous southern storm fronts that made their way into state this spring.

Black cutworms most often target "grass-type" crops in Ohio; they can cause significant economic injury to field corn, sweet corn, and wheat. However, the caterpillars may also wander into turfgrass, particularly when caterpillar populations are high and the grass is located near field crops. Dave is speculating that the high numbers of caterpillars currently being found in turfgrass in central Ohio is due to the general lack of corn; continual wet weather has prevented the planting of corn in much of the state.

The cutworms will feed on all species of turfgrasses, except for Kentucky bluegrass. Although the caterpillars may occasionally be found in home lawns, their most significant damage occurs on short-cut turfgrasses on golf course tees and greens. The caterpillars feed at night by clipping the grass blades at their base. Their feeding activity produces circular or finger-shaped sunken areas of dead, brown grass; the damage may be mistaken for ball marks. The cutworms hide in soil burrows during the day and often make use of aeration holes. Monitoring can be more easily accomplished by applying a soap solution to flush the caterpillars from their daytime hideouts. To learn more about this technique, refer to the OSU Extension Black Cutworm FactSheet at: http://bugs.osu.edu/~bugdoc/Shetlar/factsheet/turf/Blackcutworm.htm .

Black cutworms have two generations in Ohio and the second generation is most often the most damaging to turfgrass. Moths attach their eggs to the tips of grass blades, thus cultural management of the caterpillars focuses on removing grass clippings from the site. Research has shown that mowing may remove 75-90% of the eggs; however, most of the eggs will survive mowing and the resulting caterpillars can crawl back to turfgrass. So, clippings should be disposed of in areas far from the affected turfgrass. Chemical control of the second generation generally focuses on applying a pyrethroid insecticides labeled for turfgrass (e.g. beta-cyfluthrin, bifenthrin, cyfluthrin, etc.). Applications should be made late in the day and since the cutworms feed on the surface, irrigation should be avoided for several days after treatment. For more information, see:

Penn State Entomology Fact Sheet

B. WHAT ARE THOSE REDDISH THREADS IN MY LAWN???

Pam Bennett reported that red thread in turf was active due to recent cool wet weather. The fungus, Laetisaria fuciformis, thrives in humid weather and grows on the grass blades and leaf sheaths. The fungus produces the coral-pink to blood-red thread-like sclerotia on the tips of the blades; hence the name red thread. This disease can be especially severe on nitrogen-deficient turf and for the most part, regular fertility practices helps to minimize severity. In addition, as the weather changes, this fungus is likely to disappear only to show up again in the fall. Red thread doesn't usually kill a lawn but leaves circular tan to brownish patches that eventually recover. Kentucky bluegrass, perennial ryegrass, and tall fescue are more susceptible to this disease.

For more information, see:

Cornell University Cooperative Extension Fact Sheet on Red Thread Purdue Extension Turfgrass Disease Profiles on Red Thread

C. BLACK MEDIC BLOOMING IN TURF.

Black medic (Medicago lupulina) is a member of the bean family (Fabaceae). This low-growing, creeping weed is well adapted to many lawn situations. It is most commonly found in full sun, on soils low in nitrogen fertility, and in areas of thin turf cover. It has hairy, trailing, light-green or reddish-green stems rising from a tap root. It does not however, root from nodes on the stems. The roots add nitrogen to the soil by forming an association with rhizobial bacteria.

Often black medic is confused with WHITE CLOVER (Trifolium repens) or the YELLOW WOODSORREL (Oxalis stricta) because of similarities in the appearance of their leaves. However, when these plants are in bloom, their flowers make identification easy. Black medic's flowers are small, yellow, globe-shaped clusters, of 15-50 yellow flowers. White clover inflorescences occur in ball-shaped white to pink clusters of flowers that are held slightly above the foliage. Yellow woodsorrel flowers are yellow with five petals. They are up to 1/2" across and borne at the ends of stems in clusters of 1-4 flowers.

The leaves or leaflets can also be used to identify each species. Black medic is the easiest to identify by its leaflets. They are arranged alternately on the stem, and have three wedge-shaped leaflets. Black medic's center leaflet is on a separate petiole. White clover's leaves are dark-green and often have a faint, lighter green to white splotch in the middle. Yellow woodsorrel leaves are heart shaped and often are folded along the midvein.

Cultural practices for managing black medic can be very effective. It can be hand pulled. Good turf management practices promoting thick, healthy turf make it difficult for black medic to persist. Relieving soil compaction is an important cultural control. Other cultural practices that promote lawn growth include high mowing in hot weather, thorough deep watering during hot dry periods, and fertilizing, primarily in the fall. Apply post-emergent broadleaf herbicides during periods of active growth from late spring through early summer and again from early to mid-autumn. Be sure to read and follow the product's label instructions and precautions.

For more information, see:

University of Illinois Weed Information University of Minnesota Yard and Garden Brief on Black Medic

6. INDUSTRY INSIGHTS. A. POTATO LEAFHOPPERS HAVE RETURNED.

The annual migration and distribution of the potato leafhopper (PLH) (Empoasca fabae) into Ohio has occurred in most areas. Curtis Young reported seeing the little, apple-green menace in the Lima area. Although PLH will initially migrate toward field and forage crops such as alfalfa, it will also spread into many landscape plants. Of particular interest will be plants in nursery production areas. Plants such as hedge, 'Red Sunset' and 'October Glory' maples can be severely impacted in their growth form and development which may influence their salability. Leaves on these trees can be cupped and new growth stunted.

Growers of nursery stock and landscapers need to be on the lookout for PLH especially on plants still expanding new growth that could be damaged by PLH feeding. Several other tree species that are very susceptible to injury include amur, Norway and sugar maples, birches, apple, chestnut, and Persian walnut. These trees can be injured both in the landscapes and nurseries areas, especially if located near alfalfa production fields. Insecticide sprays will need to be applied in production areas to prevent reduced plant growth and vigor and to avoid distorted tree shape due to dieback and stunting. Some insecticides that appear to have fairly good activity against the PLH include foliar sprays of imidacloprid, cyfluthrin or a product with a combination of the two (e.g. Discus). Read insecticide labels carefully for application restrictions and potential chemical injury to host plants. Refer to OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" for further details.

For more information, see:

University of Kentucky Information on Potato Leafhopper Home, Yard & Garden Newsletter article from U. of Illinois

7. WEATHERWATCH.

The following weather information summarizes data collected at various Ohio Agricultural Research Development Center (OARDC) Weather Stations spanning the dates from January 1- June 1, 2011, with the exception of the soil temperatures which are readings from Thursday, June 2, 2011 at 6:05 a.m.

Weather Region of Ave. High Ave. Low Total Normal Soil Temp F Station Ohio Temp F Temp F Precip." Precip." 2"/3"

Ashtabula NE 46.3 30.5 18.24 13.0 62.17/67.25

Wooster NE 49.4 32.1 19.67 16.2 71.50/72.23

Hoytville NW 48.4 30.9 20.5 12.8 63.24/67.31 Columbus Central 53.1 35.8 20.74 18.0 81.85/80.82 Piketon South 55.3 35.5 29.09 17.7 73.03/76.70

For a link to the OARDC Weather Stations, visit: http://www.oardc.ohio-state.edu/centernet/weather.htm

8. COMING ATTRACTIONS. A. SCHOOL INTEGRATED PEST MANAGEMENT SEMINARS SCHEDULED.

When it comes to pesticide use in schools, Ohio has new school rules. Is your school in compliance? Ohio State University (OSU) Extension is available to assist Ohio schools with Ohio laws on pesticide use in schools and integrated pest management. In addition to website resources and free consultation, there are three scheduled seminars.

Toledo Seminar (Lucas County) - June 9, 2011 Collins Seminar (Huron County) - July 21, 2011 Mt. Orab Seminar (Brown County) - August 2, 2011

Registration information is available on the website: http://bugs.osu.edu/schoolipm/ .

For more information, see:

IPM Website

9. BYGLOSOPHY.

"Why try to explain miracles to your kids when you can just have them plant a garden....Robert Brault

APPENDIX - ADDITIONAL WEBSITE RESOURCES:

Ohio State University Department of Horticulture and Crop Science Plantfacts The C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC) Buckeye Turf Ohio State University Extension Master Gardener Volunteer Program Emerald Ash Borer Information

Following were the participants in the May 31st conference call: Pam Bennett (Clark); Joe Boggs (Hamilton); Julie Crook (Hamilton); Dave Dyke (Hamilton); Craig Everett (Wood); Dave Goerig (Mahoning); Tim Malinich (Lorain); Bridget Meiring (C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Cindy Meyer (Butler); Dave Shetlar (Entomology); Amy Stone (Lucas); Nancy Taylor (CWEPPDC); Curtis Young (Van Wert); and Randy Zondag (Lake).

BYGL is available via email, contact Cheryl Fischnich [email protected] to subscribe. Additional fact sheet information on any of these articles may be found through the OSU FactSheet database http://plantfacts.osu.edu/ .

BYGL is a service of OSU Extension and is aided by support from the ONLA (Ohio Nursery and Landscape Association) http://onla.org/ ; http://buckeyegardening.com/ to the OSU Extension Nursery, Landscape and Turf Team (ENLTT). Any materials in this newsletter may be reproduced for educational purposes providing the source is credited.

BYGL is available online at: http://bygl.osu.edu, a website sponsored by the Ohio State University Department of Horticulture and Crop Sciences (HCS) as part of the "Horticulture in Virtual Perspective." The online version of BYGL has images associated with the articles and links to additional information.

Where trade names are used, no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

Ohio State University Extension embraces human diversity and is committed to ensuring that all research and related educational programs are available to clientele on a nondiscriminatory basis without regard to race, color, religion, sex, age, national origin, sexual orientation, gender identity or expression, disability, or veteran status. This statement is in accordance with United States Civil Rights Laws and the USDA. Keith L. Smith, Ph.D., Associate Vice President for Agricultural Administration and Director, Ohio State University Extension, TDD No.800-589-8292 (Ohio only) or 614-292-1868.

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Where trade names are used, no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

OSU Extension embraces human diversity and is committed to ensuring that all educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, age, gender identity, or expression, disability, religion, sexual orientation, national origin, or veterans status. Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension, TDD No. 800-589-8292 (Ohio only) or 614-292-1868.

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