Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, David Goerig, Tim Malinich, Amy Stone, and Curtis Young.

June 07, 2007


This is the tenth 2007 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension agents, specialists and other contributors in Ohio.

BYGL is also made available on the Internet from the Ohio State University Horticulture and Crop Science (HCS) in Virtual Perspective website ( Additional fact sheet information on any of these articles may be found through the OSU fact sheet database (

BYGL is a service of OSU Extension and is aided by major support from the Ohio Nursery and Landscape Association (ONLA), with additional funding from the Ohio Chapter of the International Society of Arboriculture (ISA) to the OSU Extension Nursery Landscape, and Turf Team (ENLTT).

Participants in the June 05, 2007 conference included: Pam Bennett (Clark); Barb Bloetscher C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPD Clinic); Jim Chatfield (OSU Extension Center at Wooster/Hort and Crop Science); Erik Draper (Geauga); Dave Dyke (Hamilton); Gary Gao (Delaware); Tim Malinich (Lorain); Becky McCann (ABE Center); Joe Rimelspach (Plant Pathology); Dave Shetlar (Entomology); Nancy Taylor (Plant Pathology/CWEPPD Clinic); Curtis Young (Allen); and Randy Zondag (Lake)..

Additional factsheet information on any of these articles may be found through the OSU Factsheet Database (


The following weather information has been summarized from data collected from June 1-6, 2007. BYGLers have selected six locations to highlight different regions of the state to be included each week as seen in the table below. Additionally, there are weather station sites in Avon (Lorain County), Madison (Lake County), Perry (Lake County), at the Muck Crops Research Station (Huron County), at the North Central Research Station (Sandusky County), and at the Western Research Station (Clark County). The weather data collected from all the sites can be seen at

Weather Station
Region of Ohio
Ave. High Temp F Ave. Low Temp F Total Precip " Normal Precip "
Ashtabula NE 77.2 57.8 NA 3.1"
Wooster NE 76.7 57.5


Hoytville NW 78.9 60.0 0.78"


Delaware Central 76.3 58.2 0.57" 3.7"
Piketon South 80.5 60.2 0.35" 4.2"
Jackson South 82.1 58.8 1.34" 3.7"



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 the site below.

The range of GDD accumulations in Ohio from north to south is 639 to 1,037. Following is a report of GDD for several locations around Ohio as of June 6, 2007: Painesville, 639; Cleveland, 689; Toledo, 773; Canfield, 724; Lima, 753; Wooster, 772; Coshocton, 709; Columbus, 792; Springfield, 907; Dayton, 933; Cincinnati, 980; Ironton, 1,012; Portsmouth, 1,016; Piketon, 1,037; Marietta, 977; and Jackson, 1,010.

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 near you from the above list, or visiting the above web site, you can see what could be taking place in the landscape around you.

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; cottony maple scale, egg hatch, 851; panicle hydrangea, first bloom, 856; fall webworm, egg hatch (first generation), 867; mimosa webworm, egg hatch (first generation), 874; fuzzy deutzia, full bloom, 884; winged euonymus scale, egg hatch, 892; spruce budscale, egg hatch, 894; winterberry holly, full bloom, 897; panicled goldenraintree, first bloom, 924; June bride littleleaf linden, first bloom, 953; azalea bark scale, egg hatch, 957; Japanese beetle, adult emergence, 970; rosebay rhododendron, first bloom, 1010; June bride littleleaf linden, full bloom, 1115; and bottlebrush buckeye, first bloom, 1158.

Take some time to go to the GDD website at and see what it offers because it is more than just current GDDs. New additions to the Summary of Phenological Events chart include links to factsheets, bulletins and images related to most of the plants and pests highlighted on the web page. The information covered by these materials includes diseases and insect pests.


Read all about perennials and landscape trees and shrubs in the ONLA publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio." The descriptions and photographs of plants were provided for these publications by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at, for $5.00. Click on "garden store" and then "ONLA plant guides." ONLA members can purchase these in quantities at a reduced price at .

* WOODY ORNAMENTAL OF THE WEEK. (Cornus kousa var. chinensis). Kousa dogwoods are blooming throughout the state now. Here is a description of this lovely small tree from ONLA's Landscape Plants for Ohio:

"Small (15-20 feet) trees with showy white flower bracts, appealing multi-colored bark of grays, browns and tans, stratified horizontal branching pattern, attractive dark-green leaves (red-purple fall color), and colorful, roundish raspberry-like fruits. Vase-shaped plants grow rounded with age. Prefers moist soils, but is better adapted to drought than C. florida. Flowers three weeks later and has blossoms elevated above the foliage by short flower stalks.

There are many cultivars with white and pink flower forms, variegated foliage, and other features. 'Satomi' is one popular cultivar with pink floral effects. 'Milky Way' has an abundance of flowers and fruits. Rutgers hybrids are crosses of C. kousa and C. florida with intermediate characteristics and improved disease resistance over some C. florida cultivars. Examples are 'Constellation' and 'Stellar Pink' with exceptional flowering."


Brown or black spots appearing on cars had some people seeing red this week. The suspect was ARTILLERY or SHOTGUN FUNGUS (Sphaerobolus). This fungus is commonly found in mulched gardens. It is one of the many organisms responsible for decomposing organic matter in the landscape. Mulched beds provide perfect conditions for it to thrive. The problem arises when the fungus produces small cup-shaped fruiting structures that shoot spore masses high into the air. These 1/10" diameter black globules remain stuck to anything they touch. They can pepper houses, decks, grills or any outdoor surface with tiny black marks resembling spots of tar.

In this case, however, the spots on the car were irregular in size and shape - some oval, others linear. This was enough to lay blame on local roadwork. Tim Malinich mentioned a similar problem last year when a property manager was getting complaints about such spots on cars parked at his commercial property. At Tim's urging, white sign boards were placed along the borders between parking areas and garden or turf areas. After a couple weeks the boards were collected and examined for the offending spots. This simple diagnostic tool not only offered proof that complaints were legitimate, but it provided insight as to where the problem was the worst.

To correct the problem, landscapers and gardeners can use a non-organic mulch, such as stone. Be sure not to let excess mulch accumulate in garden beds. Also, cultivation can speed decomposition of organic matter already accumulated in the beds.



No! It's two bugs in one! It's a FLEA WEEVIL! Curtis Young discovered and reported on insect damage he observed on SIBERIAN ELM (Ulmus pumila) that initially appeared to be elm leaf beetle feeding. But there were no elm leaf beetles to be found on the trees. What was found were numerous tiny brown beetles that jumped like a flea beetle when disturbed. Closer examination of the beetle revealed that it has a weevil's proboscis. Dave Shetlar suggested that the flea weevil was a leaf miner on elm. Ultimately the beetle has been identified as the EUROPEAN ELM FLEA WEEVIL (EFW) (Orchestes alni). Adult EFW skeletonize the leaves of elms producing a shot hole window pane effect mostly from the undersides of the leaves. The larvae of EFW are leaf miners. The adult female EFW chews a hole in the midrib vein of the leaf and lays an egg in it. The larvae hatch, chew through the midrib vein, and start a serpentine mine in the leaf that eventually becomes a blotch mine toward the margin of the leaf. After completing their feeding, EFW larvae pupate in the mine in a pupation chamber constructed by the larvae. New adults emerge and feed again after pupation. Reports from other states indicate there is only one generation of EFW per year. The population that Curtis observed is currently emerging as new first generation adults, which may also be the adults that will overwinter till next spring.

EFW is a relatively new introduction into the US. Curtis spent many years closely examining elms while researching the elm leaf beetle in Columbus, Ohio (1982-1988) and had not seen EFW during that time. It has only recently been reported in Illinois and Wisconsin (2003).

Elm hosts of EFW include Siberian elm and several elm hybrids with U. pumila parentage such as 'Homestead'. One disturbing note in the host list is that EFW can utilize the true Chinese elm (U. parvifolia) as a suitable host. This is unfortunate since U. parvifolia has very few known insect pest. Curtis made some additional observations on local elms including 'Homestead' and U. parvifolia and found EFW activity on both. Plant managers may need to look at elms under their care for EFW. EFW may be becoming a greater problem in landscapes than what many may realize.


Dave Shetlar received phone calls regarding damage to shrubs that had been attacked by aphids, such as twisted and curled leaves on terminal growth of winged euonymus caused by the black bean aphid. However the critter that was described to Dave did not match any aphid that he had seen feeding on the shrubs. What were described to Dave were the larvae of multicolored Asian lady beetles (Harmonia axyridis). These larvae have an orange and black colored pattern on their bodies with multiple spiny protrusions down their back. The shape of the larvae is usually described as lizard-like or gator-like. These are the 'good guys' that devoured the aphid populations, are continuing to patrol the shrubs for any additional aphids and should not be treated with an insecticide.

On the other hand, not all plant managers can afford to be patient enough to allow biocontrol agents to take care of aphid populations feeding on trees and shrubs, because the damage caused by the aphids to the plants, before they are killed by the biocontrol agents may not be acceptable. For most aphids in plant production areas, an application of the pyrethroid Talstar mixed with a 1-2% horticultural oil solution will be quite effective. Some aphids are more difficult to control and survive the Talstar treatment. For these aphids, one will have to switch to products such as Simitar or Dursban to clean up the aphid populations. No matter which insecticide is used, plant managers should watch these treated plants closely for potential flare-ups of spider mite populations.


Dave Shetlar observed several different species of sawflies feeding on their respective host plants in the Columbus area. Among the sawflies observed were those described as "slugs". Two slug sawflies that were the OAK SLUG SAWFLY (Caliroa annulipes) feeding on oak leaves and the PEAR SAWFLY (Caliroa cerasi) was damaging Amelanchier (serviceberry). Slug sawflies are so named because of their resemblance to true slugs with a slimy, unsegmented appearance. Included among the non-slug sawflies were the BLACKHEADED ASH SAWFLY (Tethida barda) feeding on ash and the WILLOW SAWFLY (Nematus ventralis) feeding on willow and poplar. Some of these sawflies have only one generation per year while others have two and more generations per year. Unmanaged populations of sawfly larvae can lead to extensive defoliation.

Management of sawflies is not difficult. Many general use insecticides work very well include acephate (Orthene), bifenthrin, carbaryl (Sevin), insecticidal soap (M-Pede), malathion (Malathion), and permethrin. Note that even though these sawfly larvae look like caterpillars, they are not true caterpillars. True caterpillars are the larvae of butterflies and moths. Sawfly larvae are the immature stage of primitive wasps. Thus, Bacillus thuringiensis (BT) based insecticides will not control sawflies. Strains of this biological insecticide are effective against various Lepidopteran larvae, but will not control sawfly larvae.


BYGLers also ran into a few other insects this week including:

* Randy Zondag reported that BLACK VINE WEEVIL (BVW) adults (Otiorhynchus sulcatus) have begun to emerge in Lake County nurseries. Randy wanted to remind producers that timely and early treatments of infested plants will decrease the number of BVW adults quickly and before much egg laying occurs.

* Randy also reported that BAGWORMS (Thyridopteryx ephemeraeformis) are hatching in Lake County. Management practices to control bagworm can be instituted in the near future.

* Dave Shetlar reported observing the first JAPANESE BEETLE (Popillia japonica) adult in the Columbus area this past weekend. This is just the start of the onslaught. This sighting also seems to be a bit early for Japanese beetle.

* Curtis Young reported LIGHTNING BEETLES (Family Lampyridae) beginning to flash across the evening skies. Dave Shetlar mentioned that the number of lightning beetles seen each season depends upon the previous year's growing conditions. Specifically, how plentiful food resources were for developing larvae. Larvae of lightning beetles feed upon the eggs of snails and slugs in the soil. When breeding conditions for snails and slugs are good, the eating for lightning beetle larvae will be good.



Bad news for scabologists Erik Draper and Jim Chatfield is of course good news for the rest of the world. Erik and Jim keep trying to collect samples of the Venturia inaequalis fungus that causes APPLE SCAB from certain taxa of crabapples in their Crablandia plot in Wooster. They are working on a V. inaequalis race study with Janna Beckerman of Purdue. Alas, for these pusillanimous pussyfoots of parasitism, scab is still fairly hard to come by in this relatively dry spring.

Some diseases have been reported throughout the state, including MAPLE ANTHRACNOSE AND ASH ANTHRACNOSE diseases, causing grayish-black water-soaked blotching along leaf veins, WATERLEAF RUST on this common woodland wildflower, and even POWDERY MILDEW ON QUACKGRASS, a case where bad news for the plant is good news for horticulturists not so fond of this pesky weed.

* POWDERY MILDEW on common ninebark (Physocarpus opulifolius). The symptoms include leaf curling which can be confused with herbicide injury.



Red thread is building up in lawns in Ohio. This disease often appears in turf areas of slow growth. The slow growth may be caused by poor soil conditions, dry soils, low fertilization (nitrogen and /or phosphorus) or environmental factors that do not promote optimum growth of the turfgrass. Damage is caused by the fungal pathogen Laetisaria fuciformis. All cool-season grasses are susceptible. At this time, perennial ryegrass, fine fescues and some Kentucky bluegrasses have been infected.

The reddish- to pink colored fungal mycelium (called sclerotia) are visible and are useful for identifying the disease in the field. In some cases, there may be more thread like structures of the fungus and in other cases the fungal growth looks more like fluffy masses of pink mold. Some people describe the fungus as looking like pink cotton candy in the lawn or small pieces of pink bubble gum on leaf blades.

From a distance, red thread symptoms appear as circular to irregular patches of tan or pink turf anywhere from 1-2" in diameter to over 1' across. The pink color is caused by pink mycelium on leaf blades. As the damage occurs and the affected grass blades die, the symptoms appear more of a tan or brown color but close inspection of the leaves may reveal the remnants of the pinkish colored fungus adhering to some leaves. The disease does not kill the turf but causes leaves to die. If nothing is done the turf will eventually grow back.

The most important non-fungicide approach for management is to implement an adequate fertility program. It is important to have adequate nitrogen and phosphorous levels. A good fertility program implemented over two to three years will often drastically reduce red thread problems. Other cultural practices that promote healthy turf and vigorous growth also helps suppress red thread. If a fungicide application is used some products to consider are Iprodione, Flutolanil, Chlorothalonil, Mancozeb, Myclobutanil, Triadimefon, Propiconazole, Fenarimol, Polyoxin D zinc salt, Azoxystrobin, Trifloxystrobin, and Fluoxastrobin. Remember preventative applications made to lawns, before disease occurs, are much more effective than curative treatments. Read the label on the fungicide for correct use procedures.


Although turfgrass in many parts of Ohio had turned brown after the extreme heat experienced last week, the welcome rain and cooler temperatures this week should have revived the turfgrass, enabling it to green up again.

Turfgrass which turned brown last week should be carefully inspected to accurately determine why it turned brown. The following questions should help guide the process to determine the cause of the brown turf: 1) Was the turfgrass newly sodded or seeded? If new turf or sod was used, was the soil properly prepared by removing stones and other debris from the finished bed, and the soil graded to allow even drainage?

2) Using a cup cutter or other device to examine the soil profile, determine the depth of the thatch and examine the texture of the soil. Send a sample of the soil to a lab to obtain the pH and nutrient quality, and adjust as recommended. If large rocks or other materials are below the root zone, the objects should be removed if at all possible.

3) How thick is the thatch layer? If the thatch is 1/2" or more, the lawn should be core aerated as soon as possible. This helps to promote deep root development and encourage microorganisms to degrade the dead layer of roots, stems and organic debris.

4) Is it Billbug damage? BLUEGRASS BILLBUGS are enjoying a "good year" and can cause extensive damage if not controlled. The eggs of the white, legless larvae are laid in the lower stems of the grass. As the larvae feed, they tunnel down the stem to the crown. They may feed on several stems before they are too large in diameter to hide within the stems, at which point, they will crawl out and chew the crowns, roots and rhizomes. Significant damage occurs at this stage. The larvae then form a pupal cell in the soil and emerge as adults from August-September.

Once the larvae leave the turfgrass stems, control is not effective, therefore it is important to LOOK NOW for evidence of billbug damage. Tug on a small handful of brown turgrass stems. If the stems break easily, inspect the broken ends for frass, or sawdust, and a hollowed stem. Test several patches of brown turf stems. If billbug tunneling is present, treat immediately with imidacloprid (Merit), Arena (clothianidin) or Meridian (thiamethoxam) and irrigate thoroughly.



Gary Gao and Michael Loos both received a phone call about sour mulch causing damage to tender ornamental plants. Although mulch provides many benefits to garden and landscape plants, occasionally wood mulch that has been improperly stockpiled or composted can lead to plant injury or even death. Plant injury occurs when heat arises from improperly stockpiled mulch or toxic chemicals are released due to improperly composted mulch.

When mulch is stored in tall piles and allowed to stand for long periods, the material in the center of the pile begins to compost anaerobically (without air) and may sour. The term "sour" refers to the extreme acidity that occurs under such conditions. The pH of sour mulch can be as low as 2.5 to 4.8, while that of normal mulch is close to 7.0. Plant damaging byproducts from improperly composted mulch include methane, alcohol, ammonia and hydrogen sulfide. Another possibility is the heat generated from the composting process. This heat can directly injure plants, if the mulch is not allowed to cool first.

Injury to young and tender plants typically occurs within one day of mulch application. The leaves of tender plants might turn yellow or black, and could also drop. Watering the mulch may help wash away toxic accumulations; however, it could be too late if toxic chemicals have already evaporated or leached out into the soil. It is much easier to prevent this injury by simply smelling the mulch. If the mulch has a sharp, astringent-like, vinegar, ammonia, sulfur or silage odor, do not place it around plants. Allow the mulch to breathe and lightly water it to assist in releasing the toxic products. A good aeration will eliminate the toxic compounds in 24 hours, but to be safe, allow 3-5 days. Any mulch stockpile should not be higher than 4 feet, if possible. It is also a good idea to turn them periodically to allow some aeration.



OSU Extension in Delaware County is pleased to offer a landscape and garden diagnostic workshop from 9:30 a.m. to 12:00 p.m. on June 25. This program will be held in room G35 of Hayes Service Building at 140 North Sandusky Street, Delaware, OH 43105. It is open to Master Gardeners, home gardeners, garden center employees and landscapers. Jim Chatfield and his "new side kick", Gary Gao, will be the featured speakers. There is a $15 fee, which includes the program, refreshments and a certificate of completion. Please contact Cindy Kaelber of OSU Extension-Delaware County by phone at 740-833-2030 or email at for a registration form.


40TH ANNUAL NURSERY GROWERS OF LAKE COUNTY OHIO (NGLCO) FIELD DAY is August 14, 2007. The NGLCO Field Day will be held at Holden Arboretum in Kirtland Ohio. The program this year will feature garden tours of the 3500 acre Holden Arboretum - this year featuring a garden railroad. Time and location information will be on the following website . Master Gardeners and students will receive a special price. For further information call 440-241-7969.


"Trees are the best monuments that a man can erect to his own memory. They speak his praises without flattery and they are blessings to children yet unborn." -Lord Orrery, 1749

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 the responsibility of consulting the pesticide label and adhering to those directions.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department o f Agriculture, Keith L. Smith, Director, Ohio State University Extension.
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