Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, David Goerig, Tim Malinich, Amy Stone, and Curtis Young.
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August 16, 2007
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This is the twentieth 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
(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 14, 2007 conference included: Barb Bloetscher C. Wayne Ellett Plant & Pest Diagnostic Clinic (CWEPPDC); Joe Boggs (OSU Extension Center at Piketon/Hamilton-Clermont); Jim Chatfield (OSU Extension Center at Wooster/Horticulture and Crop Science); Erik Draper (Geauga); Gary Gao (Delaware); Dave Goerig (Mahoning); Dennis Lewandowski (Plant Pathology); Michael Loos (Cuyahoga); Dave Shetlar (Entomology); and Amy Stone (Lucas)..
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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The following weather information has been summarized from data collected from August 1-14, 2007. BYGLers have selected five 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), Jackson (Jackson 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 http://www.oardc.ohio-state.edu/newweather/ .
| Weather Station |
Region of Ohio |
Ave. High Temp F |
Ave. Low Temp F |
Total Precip " |
Normal Precip " |
| Ashtabula |
NE |
81.5F |
62.3F |
NA |
1.8" |
| Wooster |
NE |
86.1F |
65.5F |
1.57" |
1.7" |
| Hoytville |
NW |
87.6F |
66.0F |
2.85" |
1.7" |
| Delaware |
Central |
88.2F |
66.7F |
1.33" |
1.6" |
| Piketon |
South |
91.3F |
67.5F |
0.13" |
0.8" |
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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 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 http://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 http://onla.org .
*PERENNIAL PLANT OF THE WEEK. Asters are the perennial plants of the week. Some of the more popular Asters are New England Aster (Aster novae angliae), Sky Blue Aster (Aster azureus), and Smooth Aster (Aster laevis). New England Aster grows 3-7' tall and has violet 1" flowers. Sky Blue Aster grows to 24 36" tall and has blue flowers while Smooth Aster gets 2 4' tall and has violet flowers. 'Purple Dome', 'Jenny', and 'Alma Potschke' are some of the popular New England Asters.
*WOODY PLANT OF THE WEEK. Hydrangea paniculata is the woody plant of week. This popular large shrub or small tree is called panicle hydrangea and has been in bloom across the state for several weeks. The best known cultivar of this group is 'Grandiflora' or 'Pee Gee Hydrangea." Typically, panicle hydrangea has white flowers that mature to a pink. Plants bloom from July to September. The flowers form a cone shaped panicle and can be up to 8" long and 6" wide. There are quite a few other cultivars or varieties of Hydrangea paniculata available on the market. Some of them are 'Burgundy Lace,' 'Pink Diamond,''Kyushu,' 'Limelight,' 'Praecox,' 'Tardiva,' and 'Unique.'
 
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THE WEEKLY WEED
SPOTTED SPURGE (Euphorbia maculata) is a summer annual in the Euphorbiaceae family. As such, it exudes milky white sap when injured. Leaves are opposite, oval, about 1/4" in length, and green with a maroon spot at the midrib. The plant is low growing to prostrate forming mats 12" to 16" across. It has a shallow taproot and does well in compacted soils, disturbed sites, and container crops.
PROSTRATE SPURGE (Euphorbia humistrata) is very similar to spotted spurge. However, it has pale green leaves and lower nodes may root where they touch the ground. Due to their similarities, some taxonomists consider these two plants to be the same species.
Flowers are produced July through September in the axils of the upper leaves. The plant dies with the first frost. These matt-forming annuals are easily pulled from the landscape. Burndown, or non-selective herbicides are also effective. Next year's spurge crop will return from seed produced this summer and fall.
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GYPSY MOTH SUPPRESSION APPLICATIONS DUE SEPTEMBER 1ST
Amy Stone reported that the deadline to apply to the Ohio Department of Agriculture (ODA) for consideration to be part of the 2008 Gypsy Moth Suppression is quickly approaching. Those wishing to be considered should submit a completed application form with original signatures of all landowners wishing to participate and submit a map detailing the boundaries of each landowner's property, identifying each with the landowner's name.
The area needs to meet the following requirements to be part of the Suppression Program: be located in a county that has been designated quarantine for gypsy moth by ODA; be no less than 50 contiguous acres; have a tree canopy that covers no less than 50 % of the block; consist of at least 35% tree species either susceptible or resistant to gypsy moth; have an egg mass count of at least 250 egg masses per acre for residential forested areas, or 1000 egg masses per acre for uninhabited forested areas; and receive a favorable assessment from the Ohio Department of Natural Resources and the United States Fish and Wildlife Service.
If the area meets the requirements for treatment, an invoice charging the property owners 1/2 of the cost of the treatment will be mailed to the identified local coordinator. The payment must be received in full by March 1, 2008. If you have any question or desire additional information about ODA's Gypsy Moth Suppression Program, call (614)-728-6400. Additional, information is available on their website at http://www.ohioagriculture.gov/gypsymoth .

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BUG BYTES
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ITCHY ITCHIES
BYGLers reported that Extension offices are receiving calls from homeowners itching for answers to biting questions. Most of the calls centered on chiggers, but itch mites are also suspected.
Although chiggers are usually associated with spring and early summer, they can undergo three generations per year in warm climates. Contrary to popular belief, chiggers do not burrow into the skin. Once climbing onto a person, the larva crawls to a hair follicle that is usually located where clothes fit tightly such as under socks, or the waistband. The larva then injects enzymes to dissolve skin cells, and it feeds on the resulting cell-slurry.
Some people are highly sensitive to the chigger's feeding activity, and their skin will swell and surround the larva. This usually kills the chigger, and the dead larva found within the swollen skin gives rise to the burrowing misconception. Fortunately, the larva is the only stage of the mite that seeks human hosts, and it only stays on the person for a few days. Prolonged itching occurs when scratching the skin causes a local infection.
STRAW ITCH MITES (Pyemotes tritici) are tiny mites that normally are considered beneficial as they are parasites of grain pests, such as the Indianmeal moth, rice and granary weevils and pea weevils. However, when their host disappears, the mites will seek any other host, including people. When people come in contact with infested straw, hay, or grains, they are often bitten by these microscopic mites.
Another closely related mite (P. herfsi) is currently making news in Chicago. In 1994, this non-native mite was found to be a parasite of midge fly larvae (Contarinia sp., Family = Cecidomyiidae) that produce galls on oak leaves. This link to oak galls gave rise to the common name for the mite of "OAK LEAF GALL MITE." Unfortunately, the name implies the mites are the gall-makers rather than their midge fly hosts. Also, it is suspected that the mites may not be confined to feeding only on midge flies that produce oak galls. They may also parasitize midge flies that produce galls on other trees.
The mites feed on both the larvae and pupae of the midge fly gall-maker, and it is deadly to the fly. Female mites are capable of producing over 300 off-spring, so it is suspected the mites may have a significant impact on midge gall-maker populations. The mites can also have an impact on people. Apparently, once the mites leave the galls, they can rain down on and bite people. In 2004, the mites were linked to itchy outbreaks in Kansas, Nebraska, Missouri, Oklahoma and Texas. The phenomenon appears to be happening again this season with the Chicago Tribune reporting this week that over 100 people have arrived at area hospitals complaining of itchy bite-like symptoms. The oak leaf gall mite is the suspected culprit, but has not been confirmed as the itchy source.
 
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PREDATORY BUG PARADISE
Barb Bloetscher reported an upswing in samples and calls to the Clinic concerning predatory bugs (Order = Hemiptera). There are a number of Hemipteran families that are populated by insects that suck the life out of other insects. These bugs come equipped with piercing-sucking mouthparts that are used to inject paralyzing and pre-digestive enzymes into their prey. They then use their mouthparts like soda straws to suck the essence-of-insect from their hapless victims.
The bugs in the Hemipteran family Reduviidae are collectively known as assassin or ambush bugs. Both names clearly convey how these insect killers make a living. This is a large group with more than 160 North American species, and both the adults and nymphs are predators. We've highlighted various members of this family in past BYGLs, such as the descriptively named WHEEL BUG (Arilus cristatus).
The small, slender members of the Nabidae family (DAMSEL BUGS) will stalk and nab any insect that comes within reach of their long, spindly legs. The sneaky members of the Anthocoridae family are collectively known as MINUTE PIRATE BUGS, and many species hang-out on flowers to snag unsuspecting insect visitors. While they lack a patch over one eye, with a little imagination, observers may hear an "arrrr" as they dispatch their insect victims. STINK BUGS (Family Pentatomidae) are generally vilified as plant suckers, but a few species, such as the SPINDED SOLDIER BUG (Podisus maculiventris) are villainous to insects, particularly caterpillars and sawfly larvae.
Pest populations can be diminished by the assaults of these lions of the insect world. However, their effectiveness can be dramatically reduced by applications of insecticides. Look closely before spraying, don't kill the bio-allies.
 
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ARACHNOPHOBIA
Several BYGLer's reported that calls to Extension offices concerning spiders are ballooning. This is the time of the year when spiders tend to become more evident. As meat eaters, spider populations take a bit longer two increase during the season compared to plant eaters. Also, males of some species are marching about in search of female companionship, and some will invariably stroll into homes looking for love. Finally, spider webs tend to last longer and become filled with dust making them more noticeable during the dry dog-days of summer.
Some of the more interesting spiders currently being seen include FUNNEL WEB SPIDERS (Family: Agelenidae) and the ORB WEAVERS (Family: Araneidae). Funnel web spiders produce large, flat, sheet-like webs spun across grass, under rocks or boards, or over the branches of shrubs such as yews and junipers. The webs slope gently towards a narrow funnel or tube where the spider resides, awaiting its next victim. The spiders are medium-sized and resemble small wolf spiders. Funnel webs can become very evident when covered by early morning dew, or when they snare dust during droughty conditions.
Orb weavers are the true master engineers of the spider world. They spin vertical round gossamer webs with radiating spokes of structural silk covered by a spiral of sticky silk. Travelers in Ohio may be treated to the beautiful early morning view of dew-covered orb weaver webs shimmering in fields along roadways.
Ohio is also home to two species of BLACK WIDOW SPIDERS, the common black widow (Latrodectus mactans) and the northern black widow spider (L. variolus), although both are more common in the southern part of the state. Indeed, Joe Boggs reported that he received two calls this week regarding these intimidating spiders. The widow spiders are grouped with "cobweb weavers," and produce a small, tangled web. They are medium-sized spiders with bulbous abdomens. A covering of short, fine surface hairs give them a shiny or satiny sheen. Of course, black widows are... black.
The old saying, "hour-glass red, you are dead," is based on a two misconceptions. First, the deep red marking on the underside of the abdomen is not always shaped like an hour-glass, and it may be orangish-red or yellow. Some individuals have no markings, while others sport a red line on the top of the abdomen. The second misconception is that black widows represent a serious threat to Ohioans. While a black widow's bite is very serious, the spiders are not aggressive and they seldom venture into occupied homes or buildings. The widows in Ohio prefer to live outside in old abandoned buildings, barns, and wooden outhouses. In fact, painful encounters declined with the widespread adoption of indoor plumbing.
Although there are several insecticides labeled for spider control, this is not a recommended practice. There are over 600 species of spiders found in Ohio, and most primarily feed on insects. 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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ANT WARS
Dave Shetlar reported recently observing two colonies of black pavement ants (Tetramorium caespitum) engaged in a full-blown, no-holds-bared ant war. The battling ants appeared as a single undulating mass of black bodies spilling onto a sidewalk. However, a close examination revealed that every ant within the melee was locked mandible-to-mandible with another ant in mortal combat. Individual victories are often marked by the decapitation or dismemberment of the foe.
Black pavement ants are small and have pale legs, a brown to black thorax, and a black abdomen. Their habit of locating their underground colonies beside or beneath sidewalks gives rise to their common name. Mounds of loose soil particles emerging from sidewalk expansion joints are often the work of pavement ants. The ants scavenge for a wide variety of food including live and dead insects, honeydew from aphids, grease, etc.
The ants are very protective of their feeding territory, and very intolerant of nearby colonies. They are well-known for their bare-tarsal brawls with battles sometime spilling across the entire width of sidewalks. Some wars arise as territorial disputes generated by scavenging workers from adjoining colonies continually bumping into each other. These disputes are settled on a neutral battlefield between the colonies, presumably with ant-drums pounding and bugles blowing. Other wars occur because one colony simply decides to raid a nearby colony. These engagements occur right on top of the colony that's experiencing a bad ant day.
Dave noted that as with most ant fights, the brutal contest was settled quickly and cleanly. The fray was over in a few hours and nothing was left on the battlefield to mark the epic confrontation. That's because the spoils of war for ants includes the bodies of the defeated...an odd twist on the carry-out concept.

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READING BETWEEN THE SLIME
Now that some areas in Ohio have received heavy or moderate amounts of rainfall, and landscapes are beginning to green again, slug damage is reappearing. Slugs are typically associated with spring rainfall and newly planted annuals, or certain perennials such as hostas (a.k.a. "slug chow"). As the summer temperature rise and drought conditions commence, slugs and their annoying chewing damage disappear. However, this year the slugs are enjoying a resurgence of activity.
Slugs become active at dusk, sliding out from under mulch, leaves, and other moist hideouts to chew edges of leaves and make ratty looking holes on the bottom leaves. The best way to determine if slugs are active is to shine a light at an angle on the leaves. A shiny, slightly iridescent coating will be on the leaves where slugs have slimed their way across the leaves. To investigate further, go outside at dusk with a flashlight and examine damaged leaves. You may be able to catch the slugs in the act! Slugs will feed on a wide variety of plants including: marigolds; begonias; beans; the aforementioned hostas; and many shade plants.
The first step in slug management is to reduce environmental conditions favorable to slugs. Irrigation should be reduced and applied in the morning hours to allow the water to evaporate through the day. Both will minimize moisture available to slugs. The next step is to remove the mulch from under the plants being eaten, so that the slugs have no place to hide. This will also help to keep slugs on the move, and more likely to encounter baits.
Fortunately, there are several products available to help curtail slug damage. Metaldehyde, sold as "Bug Getta" and other trade names, is the standard product available. The product is now labeled for vegetable gardens! Diatomaceous earth may slow the common garden slug; however, if the large leopard slug is at work, the small sharp crystals in this product don't even scratch these giant slugs. The tried-and-true method of drowning slugs in stale beer in a pie-plate also works. The plate should be sunk in the soil so the rim is level with the soil surface, and the traps must be dumped and re-charged periodically to remain effective. Of course, handpicking and crushing is also a highly effect and very satisfying method for dispatching for these slimy creatures.

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WINDSHIELD WIPES
BYGLers also ran into a few other insect and mite problems this week including:
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DISEASE DIGEST
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PINE WILT DISEASE
Michael Loos reported that pine wilt disease was confirmed in a Scotch pine in northeast Ohio. The disease is caused by the pinewood nematode, (Bursaphelenchus xylophilus), and the nematode is carried and transmitted (vectored) to pine trees by pine sawyer beetles (Monochamus spp.). Pine sawyer beetles are a type of "longhorned beetle" (Family = Cerembycidae), so named because their antennae are longer than their bodies.
The nematode is vectored by the beetle in two ways. Newly emerged beetles undergo a "maturation feeding" period to gather nutrients that are used to mature their eggs. During this period, they move from tree to tree chewing through bark to feed on phloem. The beetles cause little damage to the trees; however, they can pick-up nematodes from infected trees and move them on their mandibles to uninfected trees. Nematodes introduced during beetle feeding can reproduce rapidly in the sapwood and a susceptible host can wilt and die within weeks of being infested if conditions are favorable to disease development.
The second way nematodes hitch a ride on pine sawyer beetles is by entering beetle pupae that are developing within infected trees. Pine sawyer beetles are attracted to and lay eggs on dead and dying pine trees. If the tree is being killed by the pinewood nematode, the two are brought into close contact during the beetle's development. The nematode can develop into two types of adults: a reproductive type that feeds and remains within the infected tree; and a non-feeding dispersal type that seeks out beetle pupae. The highly specialized dispersal type of nematode only develops in the presence of sawyer beetle pupae, and it enters the beetle pupae through the breathing holes (spiracles) to hitch a ride. The hitchhiking nematodes then infest new trees as the beetle feeds.
The pinewood nematode is not native to the U.S., and infection occurs predominantly on non-native pines such as Austrian, Scotch, and Japanese red and black pine. Feeding by the nematode causes vascular dysfunction. Infected trees can rapidly turn brown under conditions of high temperatures and moisture stress. However, field diagnosing pine wilt disease is problematic since symptoms are mimicked by wide range of problems, including environmental stress. Samples from a tree suspected to be infected should be sent to a pest and disease clinic for confirmation.
Unfortunately, nothing can be done to "cure" a tree infected by pinewood nematode. A tree that is known to be infected should be cut down and destroyed by chipping to limit spread to other trees. Remember, pine sawyer beetles will lay eggs on pine logs. The attractiveness of living pines to the beetle can be reduced by watering during drought to avoid moisture stress.

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THE MOIST CHAMBER
BYGLers spotted a few other diseases including:
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TURF TIPS
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TURFGRASS SELECTION: PART II
In last week's installment on turfgrass selection, we covered the value of using turfgrass seed blends versus mixtures where a single species in a turfgrass stand is favored over multiple species. This week, we tackle selecting species, and choosing cultivars.
Turfgrass managers in Ohio typically work with three species of cool-season grasses: Kentucky bluegrass (Poa pratensis); turf-type tall fescue (Festuca arundinacea); and perennial ryegrass (Lolium perenne). Each has positive and negative characteristics; however, the overall negatives for perennial ryegrass have placed this species on the second tier behind bluegrass and fescue in the minds of most turfgrass managers.
Kentucky bluegrass and tall fescue each enjoy fan bases rivaling NASCAR drivers! For good reason, since each can produce outstanding stands of turfgrass throughout Ohio. Old thinking such as tall fescue being thick-bladed and Kentucky bluegrass being unable to tolerate conditions in southern Ohio has fallen by the wayside with continual advancements through plant selection.
Of course, to take advantage of improved genetics, turf managers must do a little homework. The National Turfgrass Evaluation Program (NTEP) is the first place to start. These research-based, non-biased trials are conducted throughout the U.S. and Canada. A summary of trial results is available on-line at: http://www.ntep.org/. Managers should first look at the summaries for overall cultivar performance within the north central region. Managers should also consult cultivar ratings specific to problems that need to be addressed. For example, if a Kentucky bluegrass seed is destined for a lawn with history of dollar spot, the table listing relative dollar spot susceptibility among cultivars should be consulted.
As noted in last week's BYGL (Part I), it is recommended that a blend of at least two cultivars be used, with three being better. The goal is to enhance genetic diversity; however, there is a caveat that must be considered. While there are a number of different named cultivars, some are closely related in terms of representing selections from the same breeding line. Using three cultivars from the same breeding line would provide limited genetic diversity. While the breeding lines are not made available through NTEP, the cultivar sponsors are listed. A phone call can yield help with determining whether or not the cultivars are "cousins."
Finally, there is one difference between Kentucky bluegrass and tall fescue that remains an important pest management consideration. There are endophyte-enhanced cultivars of tall fescue while no such cultivars are available for Kentucky bluegrass. Endophytic fungi live among the cells in the blades of tall fescue, and exude alkaloid toxins that can kill top-feeding insects. The fungi and grass have a symbiotic relationship with the fungi deriving nutrients from cell "waste products," and the plant deriving protection from insect pests. Replacing Kentucky bluegrass with endophyte-enhanced turf-type tall fescue cultivars may be the best answer for a lawn killed this season by billbugs or chinch bugs.
Too much homework? First, remember that it's all about genetics, and the old saying "you can't make a silk purse out of a sow's ear" applies. Second, a little time spent on homework now can save a lot of time (and clients!) in the future. Many turf problems can be reduced or even eliminated by making smart cultivar selections.

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INDUSTRY INSIGHT
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ASH ALERT NEARING A MILLION HITS
Need information on emerald ash borer? Check out the OSU "Ash Alert" website http://ashalert.osu.edu/ . A lot of other people have. Amy Stone reported that between October 1, 2006 and June 14, 2007, there have been 896,833 hits on the website. The site is heading for the million mark! Joe Boggs claimed he'll spend the entire upcoming weekend trying to get the site to roll-over the million-mark!

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COMING ATTRACTIONS
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GREEN INDUSTRY FALL GET TOGETHER
The Associated Green Industries Fall Get Together will be a perennial affair this year. On August 30, 2007 the dinner, tours and presentations will be held at Art Form Nurseries, 16656 Chillicothe Rd., Chagrin Falls, OH. Tours begin at 4:00, with dinner and speakers at 6:00. Topics for the evening include "Identification of Tree Issues" and "New and Valuable Perennials in the Landscape." Registration required by August 17. Go to http://lorain.osu.edu/horticulture/commhort for registration flyer or call 440-350-2582

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BYGLOSOPHY
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"Education is when you read the fine print. Experience is what you get if you don't." -- Pete Seeger
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