Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, Dave Goerig, Dan Herms, Tim Malinich, Jane Martin, Pam Sherratt, Amy Stone, and Curtis Young.
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July 22, 2004
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This is the Sixteenth 2004 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 20, 2004 conference included: Barb Bloetscher (Entomology and C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/Center at Piketon); Jim Chatfield (Center at Wooster/Horticulture and Crop Science Department); Erik Draper (Geauga); Dave Dyke (Hamilton); Dave Goerig (Mahoning); Tim Malanich (Cuyahoga); Joe Rimelspach (Plant Pathology); Pam Sherratt (Horticulture and Crop Science); Dave Shetlar (Entomology); Nancy Taylor (C. Wayne Ellett Plant and Pest Diagnostic Clinic); Curtis Young (Allen); and Randy Zondag (Lake).
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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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This week Ohio settled into what many say is typical mid summer weather: hot, humid, and localized sporadic shower activity occurred throughout the state. Randy Zondag reported the high relative humidity is showing up in Lake county as excessive dews. These dews are keeping all plant material (trees, shrub and turf) foliage wetter, longer. He went on to say this situation is cause for concern. Dave Goerig's account of the Mahoning Valley show that area starting to dry out after excessive rainfall events over the last few months. The Youngstown area is +3.47" above the recorded average for the year, while falling -0.56" below recorded rainfall average for the month.
Joe Boggs reported that rainfall for Greater Cincinnati is 0.93" above average for the year. The area has received 2.85" of rainfall thus far for July, which is 0.42" above average. However, Joe stressed the numbers are somewhat deceptive since rainfall has been boom or bust. Much of the rainfall has been in the form of spotty thundershowers, with some localized areas receiving far less than the "official" rainfall totals.
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HORT SHORTS
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TEN THINGS YOU NEED TO KNOW ABOUT LICHENS, PART IV: ARE LICHENS GOOD EATING?
After a few week's hiatus, here is the promised next chapter on lichenology. To review, remember that lichens are dual organisms, a symbiosis composed of a fungus and an alga or cyanobacterium, with the Latin name of the fungal symbiont assigned as the official Latin name of the dual organism. Also remember that lichens do not cause plant problems.
But are lichens good eating? Well, caribou, and their European cousins, Rudolph and the rest of his reindeer friends, certainly think so. They have a rumen digestive system and the bacterial flora to properly digest the complex carbohydrates that lichens have in rich abundance. Overgrazing of lichens can even result in periods of starvation and population crashes for herds. In some cases over 90% of winter food for caribou is derived from lichens. Many species of deer, mountain goats, flying squirrels and voles also use lichens as an important food. In some cases, western North American wildlife managers fell trees to deliberately make arboreal lichens more accessible for winter food. Finally, there are many mites, springtails and other smaller fauna that consider lichens as food substrates.
As for humans, lichens have several disadvantages. It is tough for us to digest the complex carbohydrates and a few lichen species are even poisonous. So "extreme cuisine" afficionados need to follow the usual precautions familiarized by the old saying re "there are old mushroom hunters - and bold mushroom hunters - but no old, bold mushroom hunters." Lichens are not mushrooms, but we trust that you get the point. There are some reports of native cultures eating certain species of lichens in times of famine.
Sometimes lichens are made palatable by going to great extreme, from adding wild onions and saskatoon berries in barbecue pits to the ages-old trick of adding them to sugar, raisins and apples (just about everything tastes good with these additives). There is even the practice of arctic populations mixing partially predigested lichens from caribou stomachs with raw fish eggs to make what is called "stomach ice cream". We well pass on that one. And yes, certain lichens have also been used on occasion as laxatives.
Finally, lichen history includes use for various value-enhanced beverages, from a bitter flavoring for beer in Siberian monasteries to fermented corn beverages in Mexico to a source of sugar for Swedish brandy distillers. All in all, though, lichens as a food source is pretty limited, except for animals and their role in the food web. Next time: types of lichens. Source: once again the wondrous "Lichens of North America".
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BUG BYTES
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CSI - WHITE PINE
Several BYGLers reported that they are receiving calls concerning dead or dying eastern white pines. The topic generated a spirited discussion regarding challenges with determining the exact cause of death of an eastern white pine tree in Ohio. All agreed that the most daunting task confronting a hort-crime scene investigator is separating primary killers - the true felons - from secondary miscreants.
Dave Shetlar noted that quick charges are often brought against conifer bark beetles because they leave behind clear evidence of their visits to the crime scene: characteristic shotgun pellet-sized holes, or "shotholes," in the victims bark. While there may appear to be solid evidence for prosecution, it is far from an open-and-shut case! There are several species of conifer bark beetles that occur in Ohio. All are in the beetle Family Scolytidae, and most are in Genera Dendroctinus, Ips, or Scolytus. However, the conifer bark beetles found in Ohio attack stressed conifers. Weakened conifers cannot defend themselves because they lack the ability to produce enough sap, or gum, to "pitch-out" borers trying to enter through the bark.
Dave indicated that some of the misplaced blame may be based on knowledge of other conifer bark beetles found elsewhere in the U.S. Indeed, there are some truly nasty herbicidal maniacs in the Scolytid hort-crime family, such as the SOUTHERN PINE BARK BEETLE (D. frontalis). This bark beetle is a true killer, and is known to take down relatively healthy conifers. It does this by mass-attacking in huge numbers to overwhelm the victim's sap-based defense mechanism. In effect, the conifer becomes a poor sap because of the lack of sap pour.
Usually, when white pines in Ohio are under attack from conifer bark beetles, it means the trees are in serious trouble because of some stress-inducing factor, such as root decline, moisture stress, etc., that predisposes the tree to bark beetle attack. This leads to a far more complex investigation involving physiological /environmental problems. However, a tree riddled with conifer bark beetle holes cannot be "saved" using an insecticide approach. The proper treatment for such infested trees is "basal pruning,".... another name for tree removal.
 
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CONIFER SAWFLIES
Dave Shetlar noted that several late season conifer sawflies are now appearing on the scene in Ohio. These include: REDHEADED PINE SAWFLY (Neodiprion lecontei); INTRODUCED PINE SAWFLY (N. similis); and WHITE PINE SAWFLY (N. pinetum). Redheaded pine sawfly larvae have red head capsules, and their bodies are yellowish-white with six rows of black spots. The sawfly overwinters in cocoons in the soil as late instar larvae, or pre-pupae. Adults emerge, mate, and lay eggs on conifers in the spring. The larvae are gregarious feeders, and their colonies may be found on Scotch, white, red, mugo, and jack pines, as well as on larch, cedar, and Norway spruce. The larvae feed on new and old needles, and occasionally on the tender bark of young twigs. Thus, this sawfly is considered to be one of the most destructive of the pine sawflies. There are at least two generations per year in Ohio.
Introduced pine sawfly larvae favor eastern white pine, but it may also be found on Scotch, jack, red, and Swiss mountain pines. The larvae have shiny black head capsules. Their bodies have a double black stripe bordered by yellow along the dorsal midline, and their sides are dark with numerous yellow and white spots. Winter is spent as cocooned larvae on the bark of their host tree. In the spring, adults emerge, mate, and lay eggs. The first generation larvae feed on the pervious years foliage. Early instars feed gregariously, but later instars feed singly. Second generation larvae feed on both new and old needles. Like the redheaded pine sawfly, larvae of this sawfly will occasionally consume bark tissue when needles are exhausted; however, high populations sufficient to cause this feeding behavior is a rare event.
White pine sawfly has a distinct preference for its namesake host. However, the sawfly may occasionally be found on pitch, shortleaf, red, mugo, and Swiss mountain pines. Adult wasps emerge in spring, mate and the females deposit eggs in the needles. Larvae are present between mid-June and late-July, and sometimes for a second generation between mid-August and late-September. The black headed larvae are yellow to white in color with four rows of square black spots running along the length of the body. Mature larvae migrate down, or drop out of the tree, to the soil or duff under the tree, where they spin brown, oval cocoons. The larvae will either pupate immediately, or remain larvae and overwinter as pre-pupae. There is one, and sometimes a partial second generation each year.
White pine sawfly feeding can result in branch or tree mortality following complete defoliation. Thus, management may be required when populations are large and the potential for extensive defoliation is high. White pine sawfly is easily managed with many common materials such as acephate, azadirachtin, carbaryl, and spinosad. Applications should be made when larvae are young or as soon as they are discovered. Remember, Bacillus thuringiensis var. kurstaki (Btk) does not work on sawfly larvae. Btk is only effective against the larvae of moths and butterflies.
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YELLOWNECKED CATERPILLARS REAR THEIR UGLY...NECKS
Joe Boggs and Dave Shetlar reported observing colonies of yellownecked caterpillars (Datana ministra) munching crabapple leaves in southwest, and central Ohio, respectively. Colonies typically defoliate single branches before the hungry hairy hoards focus their collective gastric attention on another branch. Yellownecked caterpillars possess a cosmopolitan palate, feasting upon walnut, hickory, and oak, as well as crabapple, cherry, maple, elm, beech, linden, birch, black locust, azalea, sumac, and boxwood.
Yellownecked caterpillars pass through three distinct color phases during their development, meaning that the larvae change color patterns. This trait may present an identification challenge. First instar caterpillars are copper colored with no distinct lines. The next color phase begins with the second instar caterpillars. They have distinct alternating longitudinal yellow and orangish-red lines. Last instar caterpillars show the third color phase with caterpillars having alternating longitudinal black and yellow lines.
All instars share some common traits. They are all covered with white to yellowish-white hairs, although the hairs are most evident during the third color phase. All instars have black head capsules and a characteristic bright orangish-yellow segment behind the head, from which this insect gets its common name. Finally, regardless of instar stage, when the caterpillars are disturbed, they lift their heads and tails causing their bodies to become "U" shaped. Yellownecks have two, and possibly three generations per year. Since they feed in colonies, the caterpillars generally defoliate their hosts one branch at a time, unless populations are high and numerous colonies occur on a single host. With multiple generations, this caterpillar can potentially completely defoliate its host in one season.
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ALONG CAME A SPIDER
Several BYGLers noted that spiders seem to be everywhere! This is the time of year when populations of a number of predators seem to explode, including spiders. There are over 600 species of spiders found in Ohio. Only three, the black widow spider (Lactrodectus mactans) and two "fiddle-backed" spiders, the brown recluse (Loxosceles reclusa) and the brown spider (L. rufescens), are considered dangerous. Readers should remember that all spiders are predators, and all species in Ohio feed primarily on insects. Beyond their beneficial status, spiders are also fascinating creatures that exhibit a wide range of beautiful color patterns and some spectacular engineering feats.
Some of the interesting spiders currently being seen include the FUNNEL or SHEET WEB spiders (Family: Agelenidae) and the ORB WEAVERS (Family: Araneidae). The funnel and sheet web spiders produce large, flat, sheet-like webs across grass, under rocks or boards, or over the branches of shrubs such as yews and junipers. These webs are made more evident when covered with morning dew. The funnel weavers include a funnel-shaped tube in their web construction. On shrubs, the tube leads down into the plant material and serves as a place of concealment for the spider. When the spider senses vibrations from a trapped victim, it darts out, grabs the prey, injects a toxin, then carries its victim back into the tube. The sheet web spiders await the entanglement of their food by standing upright on the surface of the web or by hanging upside down on the underside of the web, depending upon the spider species.
The weavers spin orb shaped webs and they are the master engineers of the spider world. Two Ohio species are remarkable for both their web spinning ability and their colors. The MARBLED ORB WEAVER (Araneus marmoreus) is a rotund, medium-sized, conspicuously marked spider that may be found in tall grasses or on buildings. Its legs are bright orangish-red with white bands and the bulbous abdomen has a marbled pattern of brown or purple on a field of orange or yellow. This beautiful spider is found at the edge of its large, spiraling web at night. In the morning, it consumes its web and hides until nightfall. In the early evening hours, it spins a new web.
The GARDEN SPIDER (Argiope aurantia), another orb weaver, is a large spider with a leg span that can exceed two inches. The legs are black with reddish or yellow bands. The mostly black abdomen is conspicuously marked with yellow or yellowish-orange spots and bands. This spider is active during the day and usually spins its web in tall weeds. The spider can be found resting in the middle of the web atop a zig-zag pattern of coarse webbing that reflects ultra-violet light and attracts insects.
Although there are several insecticides labeled for spider control, this is not a recommended practice. Spiders are important in reducing insect pest populations. Homeowners are urged to practice restraint, appreciation, and understanding. Aside from providing free Halloween decorations, spiders also provide a great service by reducing the need for controlling more significant pests.
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TIME FOR TICK TALK
Over a dozen ticks were found on a homeowner's leg after working in her urban yard in NW Clermont County. Fortunately, several of them were submitted to the CWEPPDC, for identification, as they were the engorged larvae of the LONE STAR TICK, Amblyoma americana, vectors of ehrlichiosis, tularemia, and to a lesser extent, Rocky Mountain Spotted Fever. Within the last two years, this tick has enjoyed a population explosion, and has been found in 28 Ohio counties, most notably the southeast, southwest, and central parts of the state. The Department of Health (ODH), Vector Borne Disease specialists stated that as larvae, the lone star ticks do not migrate far from where the fully engorged, 7/16" long female lays her eggs, so when a person or other warm blooded animal passes that vicinity, they tend to latch on in high numbers. Panicked "victims", seeing so many ticks on them at once, usually kill the ticks then call a doctor, pest control operator, or County Extension Educator for advice and control. Unfortunately, once dead, the ticks can not be tested to confirm if they were carrying any disease.
Once the 6-legged larvae have fed for 3-9 days, they drop off, molt, and become 8 legged nymphs. At this point, the ticks are carried to other shaded, wild areas, where fox, squirrels, rabbits, skunks, raccoons, cats, and ground nesting birds visit. Engorged larvae are round, reddish, and .2mm long after feeding on smaller animals, while the nymphs seek small animals as well as dogs, deer, and cattle. All three stages will feed on humans.
The lone star tick adult female is relatively easy to identify as she is 1/8" long with fairly long palps and a white spot at the rear tip of the heart-shaped scutum. Males are slightly smaller and reddish brown. Both have oval, shiny eyes on the margin of the scutum.
The most important point regarding any tick attached to a human or pet, is that the ticks should be removed according to ODH's guidelines, to prevent infection or possible transmission of a disease that the tick may be vectoring. ODH advises that the tick be grasped with tweezers at the base of its head, as close to the skin as possible. The tick should then be pulled slowly but firmly, until the tick releases its grip. If forceps are not available and fingers are used, wash hands immediately afterward. The area should then be washed thoroughly with soap and water and the tick kept alive in a medicine bottle, or something similar with a small piece of moist cotton. Label the bottle with the date when the tick was found and keep it cool and in a safe place. If symptoms develop (depends upon the tick that was removed), take the tick to a doctor who can send it to ODH if necessary.
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SPRINGTAILS REBOUND NEAR HOMES
Reports and samples of springtails invading yards and homes continues with the intermittent rainy days this season. Springtails are simple insects with a gradual metamorphosis and require a moist environment to survive. Normally found under leaf litter in woods or under fallen trees, springtails feed on rotting leaves and debris, bacteria, fungi, lichens, pollen, and insect remains, however they are equally at home under mulch, landscape timbers, landscapes with leaking pipes and/or routine irrigation, or in stacks of firewood. Indoors they will frequent bathrooms, damp basements, moldy paper and fabric, or crawl spaces.
Springtails can be recognized by their small (1/8" or less) size, oblong shape, and soft, scaly, appearance. They usually have four segmented antennae and a furcula (spring) coiled underneath them. This furcula stays compressed until the springtail needs to escape. With a quick release of the spring, the springtail bounds up to 15x its length to safety.
To manage this pest when populations rebound, keep mulch less than 2" deep and at least 6-8" away from the parameter of the building. Repair sources of perpetual moisture inside and outside the home and seal cracks and voids where springtails can enter. Talstar can be used around the outside foundation when necessary, following label directions
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WINDSHIELD WIPE
BYGLers also ran into a few other insects this week including:
* Dave Shetlar reported that BAGWORM (Thyridopteryx ephemeraeformis) bags are now 3/4" to 1" long, and the caterpillars are causing noticeable damage in central Ohio. The size of the bags means the caterpillars are now too large to be effectively controlled using Bacillus thuringiensis, or Bt (e.g. Dipel, Thuricide, or Caterpillar Attack). Traditional insecticides will now need to be used; however, applications should be made soon since caterpillars have the ability to skip the final instar stage and pupate when exposed to insecticides. Curtis Young observed bagworms in northwestern Ohio and reported their size to be 1/2" or less currently. Thus, Bt would still be functional in his area.
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DISEASE DIGEST
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THE MOIST CHAMBER
Samples received in OSU Extension offices and the C. Wayne Ellett Plant and Pest Diagnostic Clinic of recent note include:
*DOWNY MILDEW and BLACK SPOT on ROSES. Randy Zondag and others note that the dewy mornings, excessive moisture and high relative humidities this summer continue to plague managers of rose gardens. Prevention of new infections with fungicides as mentioned in earlier BYGLS is essential, as is continuing sanitation efforts. Do not let the amount of fungal inoculum build up in rose gardens: host a garden clean-up party now and do not wait until the entire planting is on the ground.
*Nancy Taylor reports receiving samples of VERTICILLIUM WILT on SMOKEBUSH and SUGAR MAPLE in the PPDC. Often the shoot dieback associated with vascular plugging on these plants reminds horticulturists of the "shepherd's crook" symptoms associated with bacterial fireblight. In fact Nancy recently received smokebush samples in which the senders assumed that fireblight was involved. Smokebush (Cotinus spp.), though, is not in the Rosaceae and is not susceptible to fireblight, so it is a reminder that the symptoms of "shepherd's crooking" are not exclusive to fireblight infections. This is of course not news to those in the 17 year cicada areas of Ohio this season. Oviposition damage from female cicadas causes shepherd's crook symptoms, but is of course not related to fireblight.
*Other diseases noted include Volutella leaf blotch and stem canker on pachysandra, Phytophthora crown and root rot on PG hydrangea which were planted too deep, and considerable apple scab disease on crabapple. Stay tuned in next week's BYGL for a summary of the latest crabapple scab trials from Crablandia at Secrest Arboretum. Even in this heavy scab year there are dozens of cultivars with no scab at all and many more with only moderate scab.
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TURF TIPS
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RUSTY TURF
Pam Sherratt reported that RUST (Puccinia spp.) is becoming a noticeable, as well as a colorful problem on perennial ryegrass and common Kentucky bluegrass in home lawns in many areas of Ohio. The fungal disease gets its name from the production of massive quantities of orangish spores from pustules on the surface of infected blades. The spores stick to shoes, dog feet, dog fur, and any other item contacting the infected turf. Aside from generating questions regarding orange tennis shoes, orange dogs, etc., the spores may also find their way onto home carpets, provoking more colorful language.
Rust is favored by warm summer days with cool nights, and heavy morning dew, or frequent rain showers that keep grass wet. In addition, turf with a reduced growth rate is more heavily affected. Reduced growth may be due to a lack of nitrogen, soil compaction, or any other growth-limiting factor.
The damage from this disease is mostly aesthetic, and is not likely to kill the turf. Thus, fungicidal applications are generally not recommended for home lawns. A fertilizer application, coupled with watering, will stimulate turf growth and allow plants to recover. However, at this time of the year, both carry some risk since improper watering and heavy nitrogen may support the development of other more serious fungal diseases. Rather than trying to fertilize their way out of the immediate problem, home owners should be advised to implement a more comprehensive multi-seasonal lawn fertilization program, coupled with helpful cultural practices such as core aeration in the fall.
A more long-term solution is to avoid the disease altogether by using resistant cultivars of turfgrass. Pam noted that she was amazed at the range of susceptibility of perennial ryegrass cultivars in the National Turfgrass Evaluation Program (NTEP) plots at the OSU Turfgrass Research Center. She indicated some cultivars are virtually free of infection, while others are being hammered! NTEP evaluation results are available online at the following web site: http://www.ntep.org/
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RHIZOMATOUS TALL FESCUES
There has been tremendous interest recently in the tall fescue grasses that purportedly have rhizomes. After one year of research at OSU, we have some preliminary findings to report.
*The tall fescue (Festuca arundinacea) cultivars in our study were: LabarinthRTF®, Grande II, Titan Ltd., Rendition, Kittyhawk 2000 and Winter Active Fescue (WAF). Several of the tall fescue cultivars had dark green, fine leaf textures and a higher sward density, particularly WAF and Grande II. Furthermore, Grande II blended well with Kentucky bluegrass at the 1.5 inch mowing height.
*Percentage of tall fescue plants with rhizome activity were as follows: LabarinthRTF® = 10%, Grande II = 11%, Titan Ltd., Rendition, & Kittyhawk 2000 blend = 13%, Rendition alone = 6%, and Winter Active Fescue = 12.3%.
*The percent of tall fescue plants exhibiting rhizomes is far lower than initial, unpublished research has suggested (i.e. 90-95% rhizome activity). However, testing has previously taken place on spaced plants in non-compacted soils and our study took place in a dense sward of grass on native soil. This would suggest that tall fescue rhizome activity is dependent upon soil compaction and sward density.
*The cultivar in the statistical grouping that displayed the best wear tolerance was Grande II. Labarinth RTF® was not particularly wear tolerant. The Titan Ltd, Rendition + Kittyhawk 2000 blend did not perform as well as the monostand of Rendition, suggesting that a monostand of tall fescue may have better wear tolerance than a blend.
More results will follow as the study progresses.
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TURF BEETLES FLY
While JAPANESE BEETLE populations have been spotty, the NORTHERN MASKED CHAFERS are enjoying a good year in many Ohio counties. If either beetle is found in high numbers, dont panic! Remember that Japanese beetles lay eggs in green, lush lawns and that with adequate amounts of water, turfgrass with small populations of grubs can be hydroponically resuscitated. Grubs of both grubs can still be treated with imidaclooprid (through early August) or halofenozide (mid July). Make sure to water the products well after application.
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CHINCH BUGS SUCKING TURF
The second generation of chinch bugs are out and sucking turfgrass in many Ohio neighborhoods. Assumed to be a problem in dry years only, Dr. Shetlar has discovered that chinch bugs have a tolerance to Beauveria disease and can withstand wet years. Look for reddish yellow patches and 1/8" quick moving black bugs running on the soil surface under the canopy. Several pyrethroids will effectively control chinch bugs, however if the turfgrass manager waits until the damage is present, recovery will be slow. See OSU Bulletin L-187 "Management of Turfgrass Pests" for more information about turfgrass pests.
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INDUSTRY INSIGHT
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PLANT HEALTH CARE WORKSHOP
The 6th annual Plant Health Care Workshop was held last week at the Ohio Agricultural Research and Development Center of OSU in Wooster. The focus was on abiotic disorders of plants. Here are a few highlights.
*We discussed the all important ubiquity of abiotic factors in plant decline. Biotic disorders are those caused by insects and mites that feed on plants and cause damage and by plant pathogens that cause host-parasite infections. In contrast to these biotic organism-to-organism disorders, abiotic factors leading to disorders involve moisture extremes, nutrient deficiencies, environmental factors, and chemical injury. So we discussed pH-related micronutrient deficiencies such as manganese deficiency of red maple and iron deficiency of pin oak and birches. We discussed oxygen deficiency to root systems when transplants are installed too deep, both due to buried root systems coming out of the nursery and due to on-site deep planting below grade.
*We talked about herbicide injury due to drift, due to not carefully following label directions as to which plants are sensitive, and due to volatilization of ester formulations of growth regulator herbicides when applied at high temperatures. We talked about some of the "atypical" types of damage from glyphosate herbicide which sometimes show up on subsequent years if applications are not made carefully, including proliferation of shoots and canker development on thin-barked plants. We talked about lightning injury and we discussed juglone injury to sensitive plants grown too close to the roots of black walnut.
*We often focused on diagnostics. A good example is why pachysandra leaves yellow. Sometimes it is due to biotic causes such as Volutella blight (with accompanying leaf lesions and stem cankers) and oystershell or euonymus scale. Sometimes it is abiotic factors that cause the yellowing, such as iron deficiency in high pH (alkaline) soils. More often than not though it is just due to being planted in overly sunny sites.
*One of the components of all the PHC programs is a diagnostic quiz which attendees work on over the two days. This year the group did very well on a mix of abiotic and biotic problems,. distinguishing between the two and honing their skills. Samples included everything from phosphorus-induced iron deficiency on a maple to a look at hemlock woolly adelgid insects.
*The two time returning champion of these quizzes, who won free admission to the last two PHC workshop for his skills was arborist extraordinaire Skip Duncan from the central Ohio area. He was nosed out this year by Nancy Kronberg of OSU Extension in Hancock County. One other notable diagnostic feat this year was the all-time best answer to a sample, the first ever awarded 1 &frac; points out of a possible 1. About half the class correctly identified "Roundup Damage On Poison Ivy".for one of the samples. The transcendent 1 &frac; pointer though, earning an entire can of Almond Roca, for this poison ivy chemical injury, was the pointed cry-from-the heart answer of -- "Not Enough Roundup Damage."
*If you missed this year's Plant Health Care Workshop, do not despair. There is always next year. The topic for the 2005 PHC Worshop, to be held in Wooster on July 13-15, 2005 will be "Weeds", including identification, biology, control, weed ecology, gene drift, and more.
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NATIVE SOIL ATHLETIC FIELDS AND SAND TOPDRESSING
We have had a lot of questions recently about what type of sand topdressing is best for native soil athletic fields. Many athletic fields are topdressed with sand each year because sand does not readily compact, is not influenced by moisture (like native soils), and is considered "free-draining". First and foremost - not all sands are the same! If the wrong sand is used on an athletic field, it can actually create major problems with compaction and drainage. Here is what research has shown us so far:
* Many current recommendations call for sands dominated by particles in the medium-coarse size range, similar to the USGA spec.
* In addition to the SIZE of the sand, it is critical that the UNIFORMITY of the sand meets criteria. Uniform sand is crucial -- for example, if 70% of the particle sizes fell within 2 size classes. This would be classed as uniform sand.
* Shape matters! Sands ideally should be sub-rounded to sub-angular
* Light applications (<25 tones per field per year) may require sands with coarser size range than heavier applications (60-80 tones per field per year).
Anyone considering starting a sand topdressing program should contact the OSU turf group to enquire about sources of sand that meet these criteria. The bottom line: buying cheap sand at $12/ton that does not meet the criteria will probably make concrete and cause the field to fail. The right sand may cost $25/ton, but it will produce a quality field that can be used.
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OHIO PLANT DIAGNOSTIC WORKSHOPS
It is already time to think about the next series of Diagnostic Workshops, coming up this Autumn, so put these dates on your calendars. Details will be forthcoming.
Northwest Ohio, Lima --- September 17
Central Ohio, Columbus --- October 14-15
If you are interested in additional workshops, let Jim Chatfield (chatfield.1@osu.edu; 330-466-0270) or Joe Boggs (boggs.47@osu.edu; 513-260-1474) know and we will try to schedule your area for a workshop yet this Autumn or in Spring of 2005.
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NORTH CAROLINA-TENNESSEE GREENHOUSE/GARDEN CENTER FALL TOUR
As a part of its continuing education program, the Cincinnati Flower Growers Association sponsors a tour of greenhouses and garden centers each spring and fall. The tour this fall was organized by Dave Dyke and will be held from September 21st-23rd. It will include stops in the Asheville, NC and Knoxville, TN. Extension Specialists and Educators have been invited to participate to add to their knowledge and contribute their input.
Businesses to be visited in the Asheville area include: Van Wingerden International Greenhouse, BB Barns Garden Center, Jesse Israel & Sons, and the Biltmore Estate (Parker Andies, director of horticulture, will conduct the tour). Stops in Tennessee will include: Pope's Garden Center and Pope's Greenhouse.
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COMING ATTRACTIONS
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WOSU GREEN SCENE
Join host Tom Wiebell on WOSU's Green Scene gardening and landscaping Q&A radio program again this Friday night from 6:30 to 8:00 Pm. Tom's guests this week will be Joe Boggs and Barb Bloetscher, so try to stump them with your questions by calling 614-292-8513 or just listen in at 820 on your AM dial.
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BYGLOSOPHY
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"There can be no other occupation like gardening in which, if you were to creep up behind someone at their work, you would find them smiling."
- Mirabel Osler
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