Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Jane Martin, Hannah Mathers, Pam Sherratt, Amy Stone, and Curtis Young
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July 21, 2005
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This is the Sixteenth 2005 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
(http://bygl.osu.edu). Additional fact sheet information on any of
these articles may be found through the OSU fact sheet database (http://plantfacts.osu.edu).
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 July 19, 2005 conference included: Barb Bloetscher (C. Wayne Ellett Plant and Pest Diagnostic Clinic-CWEPPDC); Joe Boggs (Hamilton/Piketon); Jim Chatfield (Center at Wooster/ Horticulture and Crop Science Department-HCS); Erik Draper (Geauga); Dave Goerig (Mahoning); Dan Herms (Ohio Agricultural Research and Development Center-OARDC);Tim Malinich (Cuyahoga); Dave Shetlar (Entomology); Amy Stone (Lucas); Nancy Taylor (CWEPPDC); Curtis Young (Allen); and Randy Zondag (Lake)..
Additional factsheet information on any of these articles may be found
through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
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WEATHER WATCH
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It remains hot and dry. Even though the state appears to be above the normal precipitation level, this statistic can be misleading. Most of the state has received drenching downpours and thunderstorms; however, much of this deluge runs off of the extremely dry soils. The rain is a welcome relief, but if a hole is dug in the ground, one will discover it is still powder dry not too far below the moist surface. Below is the weather summary data from July 1 - 19, 2005.
| Weather Station |
Region of Ohio |
Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry |
NE |
83.4 |
64.7 |
N/A | N/A |
4.62 |
N/A | | Hoytville |
NW |
87.0 |
62.6 |
73.9 |
72.8 |
3.21 |
2.32 |
| Columbus |
Central |
86.0 |
66.5 |
76.0 |
73.9 |
3.68 |
2.93 |
| Miami |
SW |
86.1 |
66.4 |
75.6 |
74.0 |
1.6 |
2.36 |
| Jackson |
South |
86.4 |
65.7 |
75.2 |
73.2 |
2.92 |
2.81 |
For additional information, or to see the locations of all of the OARDC weather stations in Ohio, check out the website at http://www.oardc.ohio-state.edu/centernet/weather.htm
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HORT SHORTS
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PERENNIAL OF THE WEEK
Acanthus spinosus - Spiny Bear's Breeches. This is a dramatic perennial, that grows 3 to 4 feet tall. The plants are blooming now with spikes of pink flowers with purple bracts. Leaves are purple, leathery and deeply cut. Though the leaves appear spiny, they are not prickly. The cultivar, A. spinosissimus, does have prickly foliage. The plant performs best in full sun and will tolerate poor soils. May require some winter protection in zone 5.
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WOODY PLANT OF THE WEEK
Summertime and the clethra is bloomin'. This increasingly popular shrub SUMMERSWEET CLETHRA (Clethra alnifolia) is now displaying its very fragrant, narrow upright flower panicles which freshen entire areas of the garden. This 6-8 foot shrub also sports attractive lustrous green leaves (yellow fall foliage) and delicate persistent woody fruits effective in winter. Clethra thrives in wet sites but tolerates dry soils. There are many popular cultivars, including ‛Hummingbird‛ a 3-4 foot dwarf with 6 inch white flower panicles, 'Ruby Spice' with very ornamental rose pink flowers, and 'Sixteen Candles'.
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BUG BYTES
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EMERALD ASH BORER FOUND IN DELAWARE, OHIO
Dave Shetlar and Dan Herms reported that several ash trees located in a housing development just south of Delaware in Delaware county, Ohio, were confirmed last week by the Ohio Department of Agriculture to be infested with emerald ash borer (Agrilus planipennis) (EAB). This Asian native was first found in the United States in southeast Michigan in 2002, and in parts of Ohio in early 2003.
The Ohio Department of Agriculture (ODA), in conjunction with the United States Department of Agriculture Animal Plant Health Inspection Service (USDA APHIS), has pursued an aggressive eradication plan to halt the spread of EAB. Thus far, all but one of the EAB infestations in Ohio have remained confined to the extreme northwest corner of the state. In November, 2003, an EAB infestation was found in the Easton area of Columbus, Ohio. That infestation was apparently eradicated successfully as was an infestation in Hicksville, Ohio, that had also been discovered in 2003.
Eradication of the Delaware infestation will be vigorously pursued using the same tactics successfully employed in Easton and in Hicksville, Ohio. Currently, the ODA and USDA APHIS are working to determine the source and extent of the infestation. Once the delimitation survey is complete, all ash trees within one-half mile of visibly infested trees will be removed and destroyed. This is a critical component of the EAB eradication program because several intensive research studies have found asymptomatic trees in early stages of infestation within one-half mile of visibly infested trees.
Since the discovery of EAB in Ohio, OSU Extension has worked closely with the ODA and Ohio Department of Natural Resources to develop websites, educational materials, and training events to raise awareness of this potentially highly destructive pest. The fruits of this labor were evident in the way the Delaware County infestation was discovered. A homeowner had noticed that the top of an ash tree had failed to leaf-out this season and contacted the landscape management company that holds the contract for the development. A representative of the company visited the tree and made a preliminary diagnosis of EAB based on observing characteristic "D-shaped" emergence holes. The landscaper contacted the OSU Extension, Delaware County office who immediately steered them in the direction of the ODA through the ODA EAB Hotline: 1-888-Ohio-EAB (1-888-644-6322).
At each step of the way, from homeowner to Green Industry to Extension to ODA, the plan to discover and eradicate EAB in Ohio worked! BYGL readers should stay-tuned for updates on this infestation, and to visit the ODA EAB website at: [ http://www.ohioagriculture.gov/eab/ ]. Also, check-out the OSU EAB Ash Alert website at [ http://ashalert.osu.edu/ ] for EAB diagnostic and management factsheets, information on EAB research, frequently asked questions regarding EAB, and more.
 
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BAGWORMS BAGGING FOLIAGE
In BYGL 2005-09 (06/02/05), we reported that overwintered bagworm (Thyridopteryx ephemeraeformis) eggs had hatched in southern Ohio. This week, several BYGLers noted that feeding damage by these moth caterpillars is now becoming very evident. Populations appear to be sporadic throughout central in southern Ohio, with some heavy localized populations. Both Dave Shetlar and Joe Boggs reported they were able to clearly see this season's bagworm damage from their cars while motoring through the central and southern Ohio.
Less mobile closer inspections revealed that a high percentage of the bags in both parts of the state are now greater than 3/4" long. Larvae possessing bags greater than this length will be less susceptible to the biological insecticide, Bacillus thuringiensis or Bt (e.g., Dipel, Thuricide, or Caterpillar Attack). More traditional insecticides will now be needed; however, this control window will also draw to a close as bags reach the mature lengths of 1 1/4" to 1 1/ 2". As bagworm caterpillars near pupation, exposure to insecticides can induce early pupation allowing the caterpillars to dodge the insecticide bullet. Since there is only one generation per year, no additional damage will occur this season and populations will not be reduced for next season.
Monitoring for bagworms should extend beyond the coniferous plants that are generally considered to be preferred hosts, such as arborvitae, spruce, cedar, and juniper. Bagworms also attack numerous deciduous plants. While injury to these hosts is generally not nearly as severe as on evergreens, infested deciduous plants can serve as bagworm population reservoirs in landscapes for next season.
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MORE GALLS
Joe Boggs reported that two insect galls were the subjects of phone inquiries to his office this past week. The first were galls induced by the SPINY WITCHHAZEL APHID (Hamamelistes spinosus). This insect is most often observed in landscapes on its alternate birch hosts, where it produces corrugated leaves. However, as described by its common name, the aphid also induces the growth of spiny galls on its namesake host. These galls are now mature and very apparent.
The aphid has an interesting life cycle. It overwinters either as an egg on witchhazel twigs, or as an immature female on birch twigs. A "stem mother" aphid hatches from the eggs on witchhazel in early spring. She migrates to new buds where she feeds and lays eggs. Her feeding activity coupled with the activity of her offspring causes affected buds to develop into a light-green woody galls that is covered in spines. The young aphids develop in a chamber within the gall.
On birch, the overwintering immature females travel to expanding leaves in the spring where it gives birth to large numbers of aphids. Her offspring induce the formation of corrugations on the birch leaves, in which the aphids hide from predators. Although the galls on witchhazel and the corrugated leaves on birch may appear unsightly, neither condition is considered damaging to the health of the host trees.
The second insect gall-maker that was responsible for generating calls to the OSU Hamilton County office is the tiny midge fly (Thecodiplosis ananassii) that directs the growth of CYPRESS TWIG GALLS on baldcypress. The galls are cone-like, white to bluish-green in color, and range in size from 1/8" to 1/ 2" in length. A portion of this season's growth usually extends beyond the gall, and the new growth may become withered, turn brown and die. This only causes aesthetic injury.
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BASSWOOD LEAFMINER ADULTS EMERGING
While conducting a "bug walk-about" with Hancock County Master Gardeners in Van Buren State Park, Curtis Young and the Master Gardeners observed several AMERICAN BASSWOODS or LINDENS (Tilia americana) in which the leaves on the trees were more brown than green. Upon closer examination, the cause of the browning was the mining done by basswood leafminer larvae (Baliosus nervosus). The blotch mines produced by the larvae had coalesced into one large mine that in some cases consumed over half of the leaf area. Holding the mines up to light revealed that the miners were still inside of the mines. Ripping the mines open exposed a few larvae and several pupae. After searching a short time more, newly emerged adults were discovered on the trees as well.
In an earlier discussion about the basswood leafminer, Joe Boggs had asked how far south in the state does the basswood leafminer conduct this type of heavy feeding. In past years, most of the basswood leafminer's activity was mostly observed in NW Ohio counties such as Lucas and Wood Counties. With the Van Buren State Park observation, it is apparent that the damage caused by this leafminer extends into Hancock County. Curtis has also searched for the beetle in Allen, Hardin and Van Wert Counties and has only found scattered populations of a couple of adults in woodlots and limited leaf feeding. Have you checked your basswoods? How far into the state does this damage occur? Let us know by e-mailing Curtis Young at YOUNG.2@OSU.EDU.
If you do look for the leafminer, be sure that you find the larvae, pupae or adults associated with the damage. Browned basswood leaves are not proof enough because Japanese beetles are also feeding heavily on basswoods and lindens in a number of counties throughout the state.
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WINDSHIELD WIPE
BYGLers also ran into a few other insects and mites this week, including:
* Joe Boggs reported that fleecy PLANTHOPPER nymphs in southwest Ohio have now matured into less noticeable adults. The nymphs of several planthopper species cloak themselves in a dense tangle of waxy, white "fluff." A profusion of this white flocculent materials covering colonies of nymphs draws attention to this insect. The jumping adults (planthoppers) are much less dramatic looking. They are around 1/4" to 3/8" long, purplish blue, lime green, or powdery white. They are most easily recognized by the broad wings held vertically in a tent-like fashion and covering the sides of the body and legs.
* Dave Shetlar noted that second generation MIMOSA WEBWORMS (Homadaula anisocentra) are now appearing in central Ohio. Larvae of this moth feed gregariously within webs spun over honeylocust foliage. They feed as skeletonizers and their damage causes leaves to turn orangish-brown and appear fire-scorched. Female moths often deposit their eggs on nests from which they developed, so nests continue to expand and become more dense with silk and spent leaves from one generation to the next. Consequently, damage by this moth becomes more extensive and apparent with each succeeding generation. Once nests become large and tightly woven, control applications usually fail to penetrate the thick webbing.
* Dave also reported that he is observing a direct connection between heavy landscape infestations of TWO-SPOTTED SPIDER MITE (Tetranychus urticae) and fields of soybeans or corn located nearby. This mite has a broad host range which includes a number of field crops. Mite populations often build on surrounding crops, then the mites migrate in damaging numbers to landscape plants. Dave cautioned that landscapers should be aware of this connection, and closely monitor landscapes located next to agricultural crop areas.
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DISEASE DIGEST
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MOIST CHAMBER
SEPTORIA LEAF SPOT with small brown to gray lesions is peppering some of the shrub dogwood species, including Cornus sericea and C. alba, though damage is far less prevalent than what occurred in the wet summer of 2004. Like pears and fireblight, an evaluation plot of dogwoods and their susceptibility to Septoria leaf spot is in the future for OSU‛s Secrest Arboretum in Wooster. Other foliar diseases of ornamentals, from apple scab to rose black spot to Guignardia blotch of buckeyes and horsechestnuts continue to be predictably less prevalent than usual this year.
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TURF TIPS
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BILLBUG BROWN
Dave Shetlar reported that he is seeing a considerable amount of turfgrass mortality in lawns in central Ohio that was caused earlier in the summer by BLUEGRASS BILLBUG (Sphenophorus parvulus). As we noted earlier this season in BYGL 2005-13 (06/28/05), localized populations of this turf pest have been phenomenal.
Dave indicated that the damage appears as areas of browned grass within an otherwise healthy lawn, and the damage may be mistaken for heat/drought dormancy. However, the grass is permanently dormant...it's dead! He noted that as recent rains cause surrounding undamaged grass to begin to green-up, the mortality will become apparent, and homeowners will be seeking ways to repair the damage.
The following tips were developed during a BYGL discussion focusing on the best course of action:
* If at all possible, homeowners should do nothing immediately, and delay re-seeding until early September when declining temperatures and more frequent rainfall provide better support for re-seeding efforts.
* If re-seeding is being done using a broadcast or drop spreader, dead grass should be raked and removed prior to seeding. The dead grass can become matted and interfere with seedling growth and establishment.
* A slit-seeder (slice-seeder) is the preferred method for re-seeding damaged lawns. Dead grass does not need to be removed, and will serve the same function as straw in stabilizing the soil and reducing moisture loss. Also, running slit-seeders through and into surrounding areas of undamaged grass reduces the creation of sharp and noticeable transition zones between juvenile grass plants and the existing mature grass plants.
* The re-seeded grass should be the same species, and if possible the same cultivars, as the existing mature grass. Differences in color, texture, and growth habits between species of cool-season grasses means that re-seeding with a different species will reduce lawn quality by producing a "patch-work" lawn. The patchy areas will always remain evident. For example, many of the "lawn patch-repair" seed mixes take advantage of the rapid germination and establishment qualities of perennial ryegrass. However, unless the existing lawn is perennial ryegrass, the "repaired" areas will always look like they are under construction!
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INDUSTRY INSIGHT
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FREELOADING FUNGI
Dave Goerig reported getting samples of Stinkhorn fungi (Mutinus caninus) in the Mahoning county extension office this past week. After opening up the office windows, the Stinkhorn sample was promptly removed. The commercial landscaper was given information that explained, Mutinus caninus is one of the many nuisance fungi that can appear in mulches and composted organic materials used in our industry. Examples of nuisance fungi include the slime molds (Division Myxomycota), shotgun, or artillery fungus (Sphaerobolus), and of course, the toad stool (Lepiota americana).
Mulch and composted organic materials are useful to us and our gardens by improving soil conditions, which improves plant health. They also help to control weeds. Usually, these materials inhibit undesirable microorganisms that cause diseases of plants. These organic garden top dressings are also known to stimulate the beneficial microorganisms, including mycorrhizal fungi. The good or bad effects of adding mulches and composts to soils is generally determined by the type of organic material from which it was produced, and the degree to which it was decomposed and treated prior to its use in the landscape. The moisture content, pH, and temperature at the time we use these materials also effect the severity of freeloading nuisance fungi.
Once the product is down in the landscape bed, very little can be done to control nuisance fungi should they appear. It is recommended the fruiting bodies of the organisms be removed. Next using a spade or a four prong hook, break up the crust on top of the bed and incorporate it into the soil layer as best you can, then water down the site thoroughly. If fresh dry mulch is applied over the bed that has this problem, it is likely to occur again as soon as it drys out. Mulches should not be applied any thicker than two inches for maximum benefit to the garden.
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COMING ATTRACTIONS
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THE NEXT DIAGNOSTIC WALKABOUT
In the greater Cleveland area is Thursday July 28, in the North Olmsted area. Charles Behnke and Tim Malinich, horticulture agents with Ohio State University Extension will take a look at landscape and turf problems during the early morning walkabouts. Recertification credit available for 8 and 6A. Call 216-397-6023 to request a registration flyer with more information.
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38TH ANNUAL SUMMER FIELD DAY
Is scheduled to be held Tuesday, August 9 at Chalet DeBonne Vineyards 7743 Doty Rd. in Madison. Last year, this event attracted over 170 exhibitors and 650 participants and this year promises to be another quality event. For more detailed information on attending and/or exhibiting, call 440-241-7969, or visit the Nursery Growers of Lake County Ohio, Inc. website at: www.nglco.com
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BYGLOSOPHY
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"Knowing trees, I understand the meaning of patience. Knowing grass, I can appreciate persistence". -Hal Borland
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