This is the 7th 2008 edition of the Buckeye Yard and Garden Line (BYGL).  BYGL is developed from a Tuesday morning conference call of Extension Educators, Specialists, and other contributors in Ohio.

BYGL is available via email, contact Cheryl Fischnich [ This e-mail address is being protected from spambots, you need JavaScript enabled to view it ] to subscribe.  Additional Factsheet 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 ONLA (Ohio Nursery and Landscape Association) [ http://onla.org/ ] and [ http://buckeyegardening.com/ ] to the OSU Extension Nursery, Landscape and Turf Team (ENLTT).  Any materials in this newsletter may be reproduced for educational purposes providing the source is credited.

BYGL is available online at: [ http://bygl.osu.edu ], a web site sponsored by the Ohio State University Department of Horticulture and Crop Sciences (HCS) as part of the "Horticulture in Virtual Perspective."  The online version of BYGL has images associated with the articles and links to additional information.

Following are the participants in the May 13th conference call:  Pam Bennett (Clark); Barb Bloetscher (Entomology/C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Joe Boggs (Hamilton/Piketon); Cindy Burskey (Clermont); Jim Chatfield (OSU Extension Center at Wooster/ Hort and Crop Science);  Dave Dyke (Hamilton); Gary Gao (Delaware); David Goerig (Mahoning); John Lloyd (Rainbow Tree Care, Minneapolis MN); Michael Loos (Cuyahoga); Tim Malinich (Lorain); Joe Rimelspach (Plant Pathology); Dave Shetlar (Entomology); Amy Stone (Lucas); Curtis Young (Allen) and Randy Zondag (Lake).

The following weather information summarizes data collected at various OARDC Weather Stations spanning the dates: May 1-13, 2008, with the exception of the soil temperatures which are readings from Wednesday, May 14 at 12:05 a.m.

OARDC Weather Station

The range of GDD accumulations in Ohio from north to south is 299 to 493. Following is a report of GDD for several locations around Ohio as of May 13, 2008: Painesville, 299; Cleveland, 311; Toledo, 318; Canfield, 319; Lima, 328; Wooster, 336; Coshocton, 363; Columbus, 406; Springfield, 376; Dayton, 383; Cincinnati, 451; Ironton, 469; Portsmouth, 472; and Piketon, 493.

To put these GDD accumulations into perspective, the following is an abbreviated listing of plant and insect species with their respective phenological event and average GDD accumulations at which these events occur. Due to variations in weather, temperature, humidity, etc., these events may occur a few days earlier or later than predicted by the average GDD. By looking at a city, town, or village near you from the above list, or visiting the above web site, you can see what could be taking place in the landscape around you.

Sargent crabapple, full bloom, 298; red horsechestnut, first bloom, 304; pine needle scale, egg hatch - 1st generation, 305; cooley spruce gall adelgid, egg hatch, 308; eastern spruce gall adelgid, egg hatch, 308; common lilac, full bloom, 315; pink princess weigela, first bloom, 316; blackhaw viburnum, full bloom, 322; redosier dogwood, first bloom, 323; dwarf fothergilla, full bloom, 325; winter king hawthorn, first bloom, 328; lilac borer, adult emergence, 330; slender Deutsia, first bloom, 338; Japanese kerria, full bloom, 342; common horsechestnut, full bloom, 344; red chokeberry, full bloom, 351; doublefile viburnum, first bloom, 353; Pagoda dogwood, first bloom, 363; red Java weigela, first bloom, 365; black cherry, first bloom, 368; common sweetshrub, first bloom, 371; lesser peach tree borer, adult emergence, 372; Ohio buckeye, full bloom, 374; holly leafminer, adult emergence, 375; euonymus scale (1st generation), egg hatch, 406; Ohio pioneer thicket hawthorn, first bloom, 406; Vanhoutte spirea, full bloom, 406; winter king hawthorn, full bloom, 407; Catawba rhododendron, first bloom, 407; Tatarian honeysuckle, full bloom, 410; beautybush, first bloom, 417; black cherry, full bloom, 419; Miss Kim Manchurian lilac, first bloom, 422; white fringetree, first bloom, 435; locust leafminer, adult emergence, 437; red horsechestnut, full bloom, 440; boxwood leafminer, adult emergence, 440; doublefile viburnum, full bloom, 444; bush cinquefoil, first bloom, 444; snowmound Nippon spirea, first bloom, 445; red prince weigela, first bloom, 446; pink princess weigela, full bloom, 446; redosier dogwood, full bloom, 448; scarlet firethorn, first bloom, 459; black locust, first bloom, 467; Ohio pioneer thicket hawthorn, full bloom, 470; red buckeye, full bloom, 471; common ninebark, first bloom, 478; pagoda dogwood, full bloom, 479; umbrella magnolia, full bloom, 480; sweet mockorange, first bloom, 482; oystershell scale, egg hatch, 497; Miss Kim Manchurian lilac, full bloom, 498; and smokebush, first bloom, 501.

For more information, see:

• Growing Degree Days and Phenology for Ohio
• Understanding and Using Degree-Days

*PERENNIAL PLANT OF THE WEEK. DIANTHUS OR PINKS - (Dianthus spp.) Many varieties of Dianthus are showing-off around the state this week. This low-growing ground cover plant is great for rock gardens, perennial borders or placed along the edge of the garden. The foliage forms a mound of green, silver or blue-green and the flowers range from white to pink to red; the flowers of some varieties are fragrant. These plants do great in poor soil conditions and prefer hot dry weather; they may "melt-out" or rot in the center during rainy and humid seasons. There are a number of cultivars that provide excellent color in the garden. When the plants finish blooming, shear the dead flowers and the foliage looks great all season. 'Tiny Rubies' has a tiny rose-pink flower on a 3-4" stem; the plants form a very tight mound that grows about 8" wide. 'Firewitch' is a newer cultivar with incredible raspberry-red flowers that are around 6-8" tall.

*WOODY PLANT OF THE WEEK. DWARF FOTHERGILLA - Fothergilla gardenii. Dwarf fothergilla is in full bloom in central Ohio. It is a small shrub, reaches 3‑5', and has unusual bottlebrush‑like 1‑2" frilly white fragrant flowers blooming before or as foliage emerges. Attractive foliage is dark green in summer and turns to combinations of yellows, oranges and reds in fall. 'Mt. Airy' is one of many cultivars with excellent flower and fall foliage. Plant in moist, acidic, well‑drained soil. It is an excellent ornamental shrub for partially shaded areas.

For more information, see:

• Deciduous Trees and Shrubs with All‑Season Interests

*THE WEEKLY WEED. This week's weed is currently gracing some landscapes and farm fields in central and southern Ohio with a smattering of canary yellow. The weed producing the display is CRESSLEAF GROUNDSEL (Packera glabella), (a.k.a. BUTTERWEED (Senecio glabellus)). This member of the aster family (Asteraceae; a.k.a. Compositae) sports flowers that are daisy-like and seed heads that look like miniature dandelion puff-balls. The flowers are borne at the ends of thick, erect, stems that are green with reddish-purple streaks. The plant's cress-like leaves are responsible for the common name.

Cressleaf groundsel is a native winter annual found in the northern United States. It is a heavy seed producer, and the seed can remain viable in the soil for a number of years. For reasons that are not clearly understood, this weed has become unusually common in Ohio in recent years in cultivated fields, nurseries, and landscapes. Past reports indicate the weed may have some tolerance for 2, 4-D and may require high rates of glyphosate to be controlled. Hand pulling is an effective option in landscapes, but plants must be destroyed prior to seed maturation. Cultivation prior to flower production is also effective. Both approaches will reduce future infestations.

For more information, see:

• USDA Plant Profile

As interesting as they are, mushrooms can become a nuisance in landscapes. Large colonies can seriously impact the quality of turf. Homeowners are often concerned about risks to children or pets. There are no fungicides available to control these microbes. Control in the landscape involves manipulation of the food source or the mushrooms themselves.

*Remove individual mushrooms as they emerge. They will, however, continue to be produced until conditions change or until their food source is exhausted.

*Remove the organic food source on which they are feeding. This may be an old tree stump, buried construction material, overly thick mulch or even accumulated thatch in turf. In the case of thatch, core aerifying can speed up the decomposition process reducing the organic matter available to the mushrooms.

*Do not eat the mushrooms you find. Deaths and serious health problems occur every year to people who guessed wrong when identifying mushrooms. Do not make a casual identification of mushrooms and do not recommend eating wild mushrooms; leave the identification to the experts. Remember, "There are old mushroom hunters and bold mushroom hunters, but there are no old, bold mushroom hunters."

For more information, see:

• Wild Mushrooms

Many gardeners across Ohio have started planting warm-season vegetables and annuals. Typically, Mother's Day marks the beginning of the planting season for most of Ohio. The biggest concern for the warm-season vegetables and annuals is frost. The date when a killing frost is not likely to occur again for the season, the frost free date (less than a 50% chance of getting a killing frost) in Ohio, is around mid-May. This date might be a little bit later for northern Ohio. Some of the common warm-season vegetables are bush and pole beans, cantaloupes, cucumbers, eggplants, okra, peppers, pumpkins, squashes, tomatoes, and watermelons. Typical warm-season annuals are ageratum, balsam, begonia, celosia, coleus, impatiens, marigold, morning glory, nasturtium, nicotiana, petunia, scarlet sage, verbena, vinca, and zinnia. Hopefully, Mother Nature will not throw a monkey wrench at gardeners this year. There is a wide array of cultivars of vegetables and flowers from which to choose. Visit your local garden center and/or nursery to view your options and purchase some for your landscape. For more information on vegetables and annuals, please visit the Yard and Garden section of Ohioline at: http://ohioline.osu.edu/lines/hygs.html.

For more information, see:

• Vegetable Gardening in Ohio
• Growing Annuals in Ohio

Gary Gao asked BYGLers about the possible occurrence of the shotgun fungus inside a building. Black dots found on the interior walls of an office looked exactly like the black dots produced by shotgun or artillery fungus (Sphaerobolus spp.). The black dots inside of the office were associated with a house plant on a desk. Over the years, there have been reports of shotgun fungus or artillery fungus on house sidings/walls and cars in BYGL. It is quite rare to see shotgun fungus inside a building. Joe Boggs said that he had seen a case of shotgun fungus in a shopping mall. The fungus had shot numerous spore masses creating black dots on walls. In this case the fungus was associated with the interior plantings. The interiorscape managers had altered their mulch around the base of the plantings. Prior to the spotting on the walls, a new mulch that had been added to the interiorscape was a standard hardwood mulch normally used on the exterior of the building, the type of mulch where shot gun fungus thrives. Apparently, in Gary's case, the shot gun fungus was growing in the organic materials in the pot of the house plant.

These black dots are extremely difficult to remove. This fungus is also poorly understood. There is a good website by Dr. Don Davis of Penn State University. The website is entitled "Artillery Fungus ‑ Frequently Asked Questions (FAQ)" at: http://www.personal.psu.edu/faculty/d/d/ddd2/. Hard scrubbing with rubbing alcohol did the job in this case since the black dots were discovered very early. There are other cleaning suggestions on Dr. Davis' website. For more information, refer to OSU Extension FactSheet, HYG# 3304-98, "Control of Nuisance and Detrimental Molds (Fungi) in Mulches and Composts."

For more information, see:

• Control of Nuisance and Detrimental Molds (Fungi) in Mulches and Composts
• Shotgun fungus information from Dr. Don Davis at Penn State
• Cornell’s Fact Sheet on Shotgun Fungus

Ornamental cultivars begin when an alert plantsperson notices a tree, or part of a tree, with a unique growth characteristic (i.e. unusual leaf color, unusual leaf size or weeping growth habit). These atypical plants or shoots arise through a genetic mutation.  Buds or cuttings from the plants are then grafted onto standard trees and, if they remain true to form and have horticultural merit, they ultimately make their way into the nursery trade.  Just as the original genetic mutation occurred to produce the unique character, occasionally a reverse mutation occurs and portions of the plant 'revert' back the species' normal growth.  Some of the more common examples of reversions occur in dwarf spruces and variegated plants such as harlequin maple.  In the case of dwarf spruces, homeowners will often describe "a tree growing out of my tree."

When a reversion occurs, it's time to follow the advice of the wise TV sage, Barney Fife, and "Nip it, nip it in the bud!"  Examine the tree and determine where the reversion originated and prune off the reverted shoots.  Often, reverted shoots grow more vigorously than the rest of the tree.  If left un-pruned, reversions will dominate the tree and the homeowner who paid extra for a dwarf Alberta spruce or variegated maple is eventually left with a plain old white spruce or Norway maple.

On birch, the females move in the spring to newly expanding leaves where they feed, mature and give birth to a new crop of aphids. Aphid numbers expand quickly with each succeeding generation contributing to an ever-expanding aphid population. The feeding damage on birch causes the expanding leaves to pucker and bulge length-wise producing the characteristic leaf corrugations. The aphids cover themselves in a waxy, white, flocculent material and live on the underside of the leaves within the corrugations. The affected leaves will usually turn yellow and may prematurely fall off of the tree.

Eventually, the aphids on birch produce winged females that fly to witch-hazel. They lay eggs on the bark that will hatch into "stem mothers" the following spring. The stem mothers feed on newly expanding buds and inject chemicals that cause the buds to form a hollow, spiny, globular gall around their progeny. The winged aphids arising from the witch-hazel galls fly back to birch.

Damage to both plant hosts is usually not severe enough to warrant treatment, particularly on witch-hazel where the galls have little impact on plant health. Frequently, numerous predators will destroy aphid populations on the birch leaves. However, if heavy infestations on birch occur on highly visible plants, aphid populations can be reduced with a fall soil drench application of imidacloprid, or a spring topical application of acephate or insecticidal soap.

However, large numbers of these beetles occasionally produce noticeable leaf damage, and their nocturnal life-style makes them a deceptive defoliator. In 2000, conspicuous defoliation of oaks and maples caused by these beetles was reported in central Ohio and in some areas of Kentucky. In a few cases, the damage literally occurred overnight. The defoliation involved the removal of all of the leaf tissue with the exception of the main veins. Since the beetles are night feeders, casual observers were left in the dark trying to explain the damage. Although damage may appear severe, the beetles only fly for a few weeks, leaving plenty of time for defoliated trees to produce new leaves.

Larvae of these beetles are white grubs, with feeding habits similar to masked chafer and Japanese beetle grubs, but they prefer pasture grasses. Hence, damage to trees most often occurs near pastures. Likewise, significant May/June beetle grub populations are seldom found beneath older lawns, but are sometimes observed where new homes occupy ground which was recently in pasture. Larvae require anywhere from 1 to 5 years to complete their development, depending upon the species.

For more information, see:

• BugDoc Fact Sheet

This Sunday, May 18th, kicks off Emerald Ash Borer (EAB) Awareness Week.  The week traditionally falls just prior to the Memorial Day Weekend - the unofficial start of summer.  Several governors, county commissioners, and mayors in both infested and non-infested states, including Ohio's Governor Ted Strickland, have made proclamations.  The purpose of the week is to raise awareness about the insect that has already killed over 25 million ash trees and threatens billons more across Ohio and North America. 

In the buckeye state, we can play a very important role in slowing the spread of this exotic invader by limiting the movement of ash trees, firewood, and logs and obeying state and federal quarantines.  Campers are urged to buy local firewood at their destination.  Check out this website for additional information - http://goodcamper.info/

For more information, see:

• OSU Extension's EAB Website
• USDA/APHIS EAB Website

Currently, the caterpillars are very small (1st-3rd instar), and can sometimes go unnoticed until later in the season. Extensive feeding by the gypsy moth caterpillars can defoliate even large, mature trees. Oaks are their favorite, but they will feed on over 300 different species of plants.

For more information, see:

• ODA Gypsy Moth Maps

Last week, BYGLers Erik Draper, Joe Boggs and Jim Chatfield went down to Lexington and UK's Plant Pathology Department and the relatively new main campus arboretum, for a short one-day Plant Pathatical with John. What glories?! Oozing masses of jelly-like teliospores from CEDAR APPLE RUST, CEDAR HAWTHORN RUST and CEDAR QUINCE RUST fungi on the stems of junipers, readied for their dissemination to their alternate rosaceous hosts including apple, crabapple, hawthorn and quince. As John pointed out, the maturation of these rust fungi on junipers is ultimately the result of the arrival of spores from their alternate rosaceous hosts in summer and fall about a year and a half ago. It was wet in that late season of 2006 and that is why it is a banner year for those oozing cedar rust spores now on their juniper hosts. Spores are spreading now to hawthorns and crabapples, but only for several weeks time, both in Kentucky and Ohio.

John also noted that SPHAEROPSIS (DIPLODIA) TIP BLIGHT had truly taken its toll on Austrian pine on UK's Lexington campus over the years. Since he  
arrived there and surveyed Pinus nigra in his first years, a full 84% of these pines have been removed by the UK's grounds maintenance professionals.  Not all of those removed were technically dead, but enough damage, especially to lower branches with infections spreading ever upward, had occurred that tree removal was warranted due to these plants being "horticulturally dead" - no longer serving their intended landscape function.  Over the year's John and his graduate students have done a good deal of important work on understanding the disease cycle for Sphaeropsis tip blight of pine, including showing the extent to which latent infections may occur, in many cases, months and years before symptoms and disease expression occurs.

At John's desk, using the Mary Blight computer model, John was able to follow the occurrence of conditions for BACTERIAL FIRE BLIGHT OF APPLES, PEARS and CRABAPPLES as they developed across Kentucky.  As with all diseases, infection and disease development depend upon specific factors.  A key for serious fireblight outbreaks is whether or not significant blossom infection occurs; infections of other plant parts can also result in infection later, but major outbreaks are typically due to several days of temperatures in the 60s when petals, pistils and then nectaries of the flowers are out and are infected by the buildup of inoculum during this relatively warm spring weather when moisture is also present.  Temperature averaging 60F for a day after infection is then also a major factor.  All the details are imbedded in John's Mary Blight program that he shares with the growers in the different areas of Kentucky.  We shall miss ye, John!

Anthracnose Leaf Blight is showing up in more southerly parts of the state, especially ASH ANTHRACNOSE and OAK ANTHRACNOSE. PLUM BLACK KNOT was reported by several BYGLers. POWDERY MILDEW OF NINEBARK, namely on the 'Diablo' cultivar was reported by Erik Draper in northeast Ohio, earlier than he had ever remembered. Joe Boggs reported that it had already been "hammering" his 'Diablo' for some time in the Cincinnati area.

Although seedhead production can affect turf quality, it is a short‑term problem.  Eventually the turfgrass will literally out‑grow the problem.  Of course, recovery will occur faster on lawns that have been properly maintained (e.g. proper fertilization, watering, mowing, etc.).  Lowering mowers one-notch for one cutting can improve lawn aesthetics; however, this should not be done for multiple cuttings since low-mowing will stress the lawn. 

The propensity to produce seedheads in lawns varies among Kentucky bluegrass cultivars and this characteristic is evaluated in the National Turfgrass Evaluation Program [ http://www.ntep.org ].  Consequently, a more long‑term solution may involve selecting cultivars that are less inclined to produce seedheads. 

For more information, see:

• Soil Testing

Randy's report demonstrated three challenges with diagnosing a BVW infestation. First, although the weevil is most commonly associated taxus and rhododendrons, it can feed on over 100 different plant species. BVW may be overlooked on plants that are not commonly thought of as being hosts to this pest.

Second, adults feed on foliage and produce notches on the leaf margins. The leaf-notching damage is easy to see on leaves with smooth edges, but hard to detect on leaves with serrated edges. Third, the cream-colored, legless, grub-like larvae consume roots. The damage mimics symptoms caused by other problems including: too little, or too much water; root-rotting fungi; and vole damage. Bottom line: growers should conduct thorough whole-plant examinations of dead or dying plants before drawing diagnostic conclusions.

BVW is currently in the late instar larval stage and insecticides will have little effect on these large-sized larvae. Also, the larvae are nearing pupation. Traditionally, insecticide applications in field production have targeted the adult stage; however, adults are active for an extended period during the growing season, so multiple applications are required. Foliar applications of bifenthrin (e.g. Talstar) or permethrin (e.g. Astro) can reduce the aesthetic impact of adult leaf-notching damage, but there is a risk that some adults will escape treatments to lay eggs.

A BVW management program should also include a mid-August soil drench with imidacloprid (e.g. Merit, Marathon). The application timing targets a "bottleneck" in the life cycle of the weevil: in mid-August, a high percentage of the population is in the first instar larval stage. Management of BVW in container production can be accomplished by using preplant potting mix incorporation treatments of synthetic insecticides, such as bifenthrin (e.g. Talstar 0.2 G)

For more information, see:

• University of Minnesota Fact Sheet
• IPM of Midwest Landscapes

The registration deadline is June 5, 2008.  Space is limited to 80 attendees.  Registration will be accepted on a first come, first served basis.  Late or on‑site registration is subject to a $5.00 late fee.  Please call OSU‑Extension at 740‑833‑2030 to confirm space availability before registering onsite.  Follow this link [ http://delaware.osu.edu/horticulture/upcoming‑programs ] to download a program flyer or email Cindy Kaelber at [ This e-mail address is being protected from spambots, you need JavaScript enabled to view it ] for a program flyer.

Check out this 3 day class consisting of a hands-on approach to learning or refining plant diagnostic skills. These skills include discovering the process to properly diagnose plant problems, identification of woody plant diseases and detecting insect and mite problems. Determine how plants respond to cultural and environmental problems as hundreds of samples will be used to help participants identify symptoms. Diagnostic walks, to learn to really see the entire plant site environment, will also be a feature of this class. This experiential program will be held July 9-11, 2008 at Secrest Arboretum in Wooster, Ohio. Registration deadline is July 1 and classroom space is limited. Registration fee is $250 which includes all meals, snacks and class materials. For more information contact Kathy Smith at 614-688-3421 or visit the link below.

For more information, see:

• Ohio Woodlands Stewards Program