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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September 01, 2005
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This is the twenth-second 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 August 30, 2005 conference included: Pam Bennett (Clark), Barb Bloestcher (C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)), Joe Boggs (South Region/Hamilton), Jim Chatfield (Center at Wooster/HCS); Erik Draper (Geauga); Dave Dyke (Hamilton); Dave Shetlar (Entomology); 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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Some areas of Ohio were very dry while others had adequate moisture. This was the weather summary for the state this past week. BYGLers discussed how variable the drought conditions were. For instance, Joe Boggs and Dave Dyke live in Hamilton county, about 15 miles apart. Joe noted that he may have to re-seed his lawn due to drought damage and Dave's lawn hasn't even gone dormant.
Clark county is extremely dry. Pam Bennett noted some statistics from the Ohio Agricultural Research and Development Center (OARDC) weather station in Clark county that were quite eye-opening. The following numbers really tell the tale about why some plants are suffering. Since June 1, the area has received a total of 5.06" compared to the normal of 11.75". That doesnt seem so bad. However, add the fact that there have been 24 days over 90F and 23 days between 85 and 90F. This is 47 out of 92 days with temperatures greater than 85F. These numbers make it easy to understand why plants are suffering.
Many areas of Ohio received a well-needed rain on Tuesday.
Following is the weather summary from August 1 - 29, 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 |
83.2 |
65.0 |
N/A
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N/A |
1.98 |
N/A | | Hoytville |
NW |
85.9 |
60.9 |
73.1 |
70.6 |
0.89 |
2.73 |
| Columbus |
Central |
87.9 |
65.1 |
76.0 |
72.7 |
3.52 |
3.44 |
| Miami |
SW |
87.3 |
66.7 |
76.2 |
71.9 |
2.99 |
2.50 |
| Jackson |
South |
88.7 |
63.5 |
75.2 |
72.2 |
3.68 |
3.44 |
For a link to the OARDC Weather Stations, check out: http://www.oardc.ohio-state.edu/centernet/weather.htm
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HORT SHORTS
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PLANTS OF THE WEEK
Read all about perennials and landscape trees and shrubs in the new publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio" published by the Ohio Nursery & Landscape Association (ONLA). The descriptions and photographs of plants were provided for this new publication by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at Buckeyegardening.com for $5.00. Click on "garden store" and then "onla plant guides." ONLA members can purchase these in quantities at a reduced price at onla.org
* PERENNIAL OF THE WEEK - Miscanthus sinensis - Japanese maiden grass. This beautiful, upright grass is beginning to bloom in central Ohio. The clumps are 3 - 4' tall with arching leaves. Flowers are pint to reddish and are held in loose clusters that are about 8 - 10" long and held above the foliage. Miscanthus is very adaptable to soil conditions. There are also numerous cultivars available with a variety of features. For instance, 'Strictus' is upright, compact, and grows to about 8' tall with horizontal yellow bands on the green leaves. 'Variegatus' has leaves with white margins and tolerates light shade and 'Malepartus' is know for its sliver flowers that become white and fluffy as they dry.
*WOODY PLANT OF THE WEEK. Hibiscus syriacus - Rose-of-Sharon. Various cultivars of this popular shrub or small tree (8-12 foot) are still brightening the state. It has open, showy flowers ranging in color from white to red to purple with many color variations and combinations. Rose-of-Sharon is adaptable to both alkaline and acid soil and most soil types. Avoid sites with severe moisture extremes. This shrub provides a welcome colorful landscape effect with flowers in mid- to late-summer. The wide range of cultivars include 'Diane' with pure white flowers, 'Helene' with white-throated, plum-colored flowers, and 'Blue Satin'.
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BUG BYTES
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KATYDIDS DID!
Katydids have been common in some parts of Ohio this August. They are recognized by their large, green, leaf-like wings positioned side-by-side on top of their backs, and the familiar "Katy did, Katy didn't" chorus on late summer evenings. Although not considered to be a pest in the landscape, these Orthopterans cause concern by depositing a line of eggs just under the epidermis of small diameter branches. The eggs look like small, flat, round 1/8 - 1/4" brown disks, which lay in a row, slightly overlapping each other. The eggs hatch the following spring, but the lengthwise scar along the slender branches remains until callous tissue grows around it.
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WHEEL OF MISFORTUNE A HAZARD TO CATERPILLARS
Jim Chatfield and Joe Boggs reported observing a large number of WHEEL BUGS (Arilus cristatus) while teaching at last week's Master Gardener Advanced Training Diagnostic-Walkabout at the Wilmington College Hazard Arboretum. The bugs were cavorting among the leaves of a number of deciduous trees. Their marauding presence partially explained the conspicuous absence of FALL WEBWORM (Hyphantria cunea) caterpillars in a number of otherwise normal looking silk nests. Caterpillars and sawfly larvae are a favored prey of wheel bugs.
Wheel bugs get their very descriptive common name from a peculiar morphological feature that rises from the top of the bugs thorax. The structure looks like half of a cog-wheel, with the gear teeth clearly visible. The bugs are big, measuring over 1 1/4" long. Their color varies from light gray to bluish-gray to grayish-brown.
These bugs belong to the hemipteran family Reduviidae, which is represented in North America by over 160 different species. Members of this family are collectively known as assassin bugs or ambush bugs. Both names describe how the bugs make a living -- they are stealthy hunters. The bugs come equipped with piercing-sucking mouthparts that are used to inject paralyzing and pre-digestive enzymes into their prey. They then suck the essence-of-insect from their hapless victims. While these are beneficial insects, they should not be handled. All members of the family are capable of delivering a painful bite to people. The pain of a wheel bug bite has been described as being equal to or more powerful than a hornet sting, and taking over a week to heal.
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DISEASE DIGEST
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VERITABLE VEGETABLE RIDDLE
What grows in the garden on vine crops, turns leaves white, then yellow, then brown, and causes plants to die? The answer to this perplexing riddle as to what is shutting down pumpkins, cantaloupes, cucumbers, and all types of squash in northeast Ohio is simply POWDERY MILDEW. Erik Draper reported that this has been a banner year for this fungal disease which can hit a field of pumpkins, causing most of the leaves to collapse within about two weeks. There are two fungi responsible for wreaking havoc on vine crops, Sphaerotheca fuliginea and Erysiphe cichoracearum. S. fuliginea is the most common in Ohio.
This disease reduces overall yields by causing the plant to shut down from a lack of leaves, resulting in either a decrease in the size or number of fruit or by shortening the harvest period. As the fungus overwhelms the leaves, causing them to wither up and die, it results in the premature exposure of the fruit to the sun. This sudden exposure often causes the fruit to sunburn or ripen prematurely, forming dinky fruit with poor taste, or ripening incompletely due to one side of the fruit being overheated by the sun. It is especially annoying on pumpkins because the rind color does not develop consistently and the affected pumpkins don't seem to store as well or as long as unaffected fruit. It is a particularly annoying trait of infected pumpkin peduncles or "handles" to become dry and pithy, and then snapping off when harvested.
Powdery mildew develops quickly under favorable conditions. Favorable conditions include high relative humidity, warm temperatures, low light (due to canopy density), high plant fertility, and succulent plant growth. Powdery mildew spores are most often blown into Ohio during the spring from warmer southern areas where the disease overwinters on plants. The older, mature foliage is most susceptible to infection, while very young leaves are nearly immune. The length of time between infection and the appearance of symptoms is usually only 3 - 7 days. Large numbers of spores are produced in a short time. Control of these fungi is best achieved with genetic resistance; however, that resistance is prevalent mainly in cantaloupes and cucumbers. Fungicides are effective, but must be applied when the first symptoms of powdery mildew are found and every 7 - 10 days thereafter, depending on the chemical, until harvest.
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SCAB-RESISTANT OR IS IT?
At the Hazard Diagnostic Workshop in Wilmington, attendees were faced with an interesting quandary. Looking at a tree, attendees noticed that the leaves had classic scabby lesions, yellowing and defoliation. It was identified as apple scab, caused by the fungal pathogen, Venturia inaequalis. Yet, only some of the leaves had the lesions. Other whole areas of the tree had clean, scab-free leaves. In fact, those leaves not only were scab-free, but they were larger than the leaves on the parts of the tree that exhibited scab. Further, those branches with the scabby leaves had tiny crabapples fruits, while the other scab-free branches had apples larger than the threshold of what are classified as crabapples (less than two inches in diameter). Whazzup?
As it turned out, the tree was really two plants in one. The large crabapple-sized (in reality apples) portion was an overgrown rootstock with the crabapple portion being the scion that had been grafted onto the apple rootstock. The apple rootstock was a cultivar with excellent scab ressitance, the crabapple scion happened to be a scab-susceptible cultivar. Together they were a nifty illustration of the difference in genetic resistance to scab between these two Malus.
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MOIST CHAMBER
Other diseases reported by BYGLers this week included downy mildew on Rudbeckia, powdery mildew on a wide range of ornamentals from Norway maple to English oaks, anthracnose on euonymus, and increasing late-season development of black spot on roses which has emerged with the wetter conditions in certain areas of the state.
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INDUSTRY INSIGHT
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JAPANESE BEETLES STILL ACTIVE
Surprisingly, Japanese beetles are still present in some parts of Ohio. Because they are still active, lawn managers are wondering how to predict the time line of the grubs and the strategy to control them this fall.
Dave Shetlar stated that the Japanese beetle grubs are still in early instars and may continue to forage into late fall, depending upon soil temperatures. Check browned turfgrass for evidence of grubs; tug at the turfgrass near the soil line and pull. If grubs are present to the point that they are damaging the roots, the turfgrass, roots and some thatch peels away from the soil below, like a layer of carpet. The C-shaped white grubs are found laying on the newly exposed soil surface. If 10 or more grubs are present per square foot, and/or the turfgrass wilts easily, control may be necessary.
This late in the season, the control is limited to a few "rescue" grubicides. Contact insecticides such as trichlorfon (Dylox) kills the grubs if the soil is moist and the product is irrigated into the thatch zone. Imidacloprid helps to control grubs if applied by late August. A new product, Arena® (clotheprin) has shown efficacy when applied from mid-May to mid-September. Although a fairly new insecticide, different formulations of this neonicotinoid have shown promise to manage several difficult insect pests.
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WHITE GRUBS STILL ACTIVE IN NURSERIES
Randy Zondag noted that Europe
an masked chafer and Japanese beetle grubs were still active in nurseries. As in the above recommendations for turf, imidacloprid can be used if applied by late August and the new produce Arena® can be used at this time.
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COMING ATTRACTIONS
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DIAGNOSTIC WORKSHOP
OSU Extension, Hancock County and the OSU ENLTT, with teachers Nancy Kronberg, Joe Boggs, and Jim Chatfield announce the next Ohio Plant Diagnostic Workshop, on Wednesday, September 14 in Findlay. The location is The Lodge at Riverbend in Findlay. For a registration form on this program of the latest in diagnostic issues and problems, contact Nancy at (419) 422-3851 or (kronberg.3@osu.edu).or send $30 per person to OSU Extension, 7868 C.R. 140, Suite B, Findlay, Ohio 45840. The program starts at 9:45 a.m. and runs until approximately 4:00 p.m. Rumors are that in addition to a "marvelous lunch" there will be a good deal of screaming by all. The 2nd Annual Hancock County Master Gardener Ice Cream Feast will be included!
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OSU/ONLA NURSERY AND LANDSCAPE RESEARCH DAY
Catch up on the latest and greatest research at OSU by attending this program on September 22 at the Waterman Farm on the Columbus campus. The program starts at noon with lunch (and brief presentations) and continues until 3:45 p.m. Presenters include Dr. Hannah Mathers, Dr. Dan Herms, Michele Bigger, Alejandra Acuna, Enrico Bonello, Alieta Eyles, Don Cipollini, Nathan Kleczewski, Randy Zondag, Heping Zhu, Charles Krause, Mike Redding, Luke Case, and Richard Rathjens. The afternoon includes tours of the Waterman and Howlett Nursery Trials. There is NO COST; contact Dr. Mathers at 614-247-6195 or Luke Case at 614-292-0209 to register.
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SALSA II
The first SALSA (SECREST ACADEMY FOR LANDSCAPE SCIENCES AND ARTS) series is fully enrolled. The first two full days of programming were on July 18 and August 15. The dates for the second series of three full-day sessions are October10, November 14, and December 12. Featured topics include maintenance practices such as fall planting, fertilization and mulching, plant selection for fall landscape appeal, weed management, wildlife management in the landscape, and problems with invasive organisms. This program is held at OSU's Secrest Arboretum at the OARDC in Wooster. It is for individuals with professional or personal interest in an intensive, hands-on landscape learning experience, and is sponsored by OSUs Secrest Arboretum and the OSUE Center at Wooster.
SALSA is a learning experience, advancing knowledge of the arts and sciences of landscape horticulture through linked interactive hands-on programs. SALSA is not a series of isolated single-topic programs, nor it a full-fledged 2- or 4- year degree program. SALSA occupies the landscape between these two; it is rooted in dedication and blooming with creativity. Class size is limited. The cost of SALSA II is $300 for the full three days of programming. This fee includes considerable reference material and class curriculum notebooks, lunches and refreshments. For more information contact Joe Cochran at Secrest Arboretum (330-263-3886 or [cochran.58@osu.edu ].
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BYGLOSOPHY
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As we continue to go about our daily business, take the time to think about those affected by hurricane Katrina. Keep them in your thoughts as they work through this tragedy.
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