Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Hannah Mathers, Pam Sherratt, Amy Stone, and Curtis Young
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April 07, 2005
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This is the First 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 April 05, 2005 conference included: Pam Bennett (Clark); Barb Bloetscher (C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/Piketon); Jim Chatfield (North Region/HCS); Erik Draper (Geauga); Dave Dyke (Hamilton); Dave Goerig (Mahoning); Hannah Mathers (HCS); Dave Shetlar (Entomology); Amy Stone (Lucas); Nancy Taylor (CWEPPDC); and Curtis Young (Allen).
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 year's weather report has a new look; highlights from five OARDC (Ohio Agricultural Research and Development Center) weather stations will be summarized weekly. In addition, unusual or out of the ordinary anecdotal information will be shared when appropriate. You are urged to take particular notice and keep a summary of the weather in your area. Nothing beats putting a shovel into the soil and really seeing how wet, or dry, an area is. A weekend snow event took place in northeast Ohio. Twelve inches of snowball-sized flakes fell in northeast Ohio. Erik Draper was hoping that the 60F temperatures forecasted this week would melt winter away fairly quickly. Can things change quickly in the Buckeye state or what? Weekly summary April 1 - 5 from the OARDC Weather Stations Weather Station
| Weather Station | Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry | 60.9 | 37.9 | N/A | N/A | 0.05" | N/A | | Hoytville | 60.4 | 34.5 | 47.2 | 48.9 | 0.27" | 3.25" | | Columbus | 60.2 | 38.2 | 49.7 | 51.1 | 0.5" | 3.74" | | Miami | 63.2 | 38.3 | 51.4 | 51.3 | 0.29" | 3.87" | | Jackson | 64.4 | 34.9 | 49.1 | 52.4 | 1.21" | 3.81" |
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HORT SHORTS
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PLANT PHENOLOGY
Spring is here, despite the recent weather. Plants seemed to burst this week with the onslaught of a few warm days. There is a difference in bloom status between what was reported on Tuesday and what is in bloom now. Following was the status of plants on Tuesday morning.
In the northwest area of the state, Curtis Young reported that crocus, jonquils, and silver maple (Acer saccharinum) were in full bloom. In the northeast, Dave Goerig reported that, despite the snow, crocus and silver maples were in bloom. Jim Chatfield reported that Trilium grandiflorum was just about ready to bloom in his area.
In the Clark County area, Corneliancherry dogwood (Cornus mas), daffodils, crocus, early tulips and hepatica were in full bloom and forsythia and cut-leaf toothwort were just starting to show color. Skunk cabbage was ending its bloom period.
Forsythia, star magnolia (Magnolia stellata), Nanking cherry (Prunus tomentosa), Siberian squill, and spring beauties are in full bloom in southern Ohio. Corneliancherry dogwood was at petal drop.
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GDD (GROWING DEGREE DAYS)
GDD is a measure of the daily maximum and minimum temperature and directly relates to growth and development of plants and insects. The GDD of any zip code location in Ohio is estimated using the GDD of ten OARDC weather stations and available on the web at the site below.
The range of GDD accumulations in Ohio from north to south is 50 to 133. Following is a report of GDD for several locations around Ohio as of April 6, 2005: Painesville, 50; Cleveland, 50; Toledo, 54; Youngstown, 57; Lima, 61; Wooster, 69; Coshocton, 66; Columbus, 70; Springfield, 77; Dayton, 101; Cincinnati, 133; Ironton, 127; and Portsmouth, 127.
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.
Silver maple, first bloom, 34; corneliancherry dogwood, first bloom, 40; silver maple, full bloom, 42; red maple, first bloom, 44; northern lights forsythia, first bloom, 58; red maple, full bloom, 75; star magnolia, first bloom, 83; border forsythia, first bloom, 86; eastern tent caterpillar, egg hatch, 92; Manchu cherry, first bloom, 93; northern lights forsythia, full bloom, 94; Norway maple, first bloom, 116; border forsythia, full bloom, 116; chanticleer callery pear, first bloom, 123; sargent cherry, first bloom, 127; larch casebearer, egg hatch, 128; saucer magnolia, first bloom, 133; bradford callery pear, first bloom, 142; European pine sawfly, egg hatch, 144; weeping Higan cherry, first bloom, 145; P.J.M. rhododendron, first bloom, 147; Chanticleer callery pear, full bloom, 149; Norway maple, full bloom, 149; and inkberry leafminer, adult emergence, 150.
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NEW FEATURE! PLANT OF THE WEEK
Each week, BYGL participants will select and highlight a perennial and woody ornamental of the week. The selections come from the newly updated "Landscape Plants for Ohio" and "Perennial Plants for Ohio," both published by the ONLA (the perennials book will be available in May). The descriptions and photographs of these plants were provided for these new publications by the OSU ENLTT with great help from friends such as Bill Hendricks and Fred Hower.
*PERENNIAL OF THE WEEK - Helleborus orientalis and hybrids (Lenten rose). This genus has interesting species that bloom in late winter and early spring; some cultivars are still in bloom at this time. Flowers vary in the pink, maroon, and white ranges and are either single or double. Be sure to get down on your knees to really appreciate these flowers! Hellebores require soils high in organic matter, moisture, and shade. This is an excellent plant for woodland areas and was in full bloom at the Governor's home last Friday.
*WOODY ORNAMENTAL OF THE WEEK - Cornus mas (corneliancherry dogwood). This zone 4 plant is an excellent early-flowering, multi-stemmed, rounded to oval habit, shrub or small tree growing 15 to 20' tall. Masses of bright yellow flowers jump-start spring in the landscape; excellent for mass plantings and is adaptable to different sites. Features include dark green leaves, flaky brown bark, small cherry-red fruits, and good adaptability. In some years, this plant first flowered as early as late February or early March in northeast Ohio, but Dan Herms reported that its first bloom this year did not burst forth until the last week of March in Wooster. It is in full bloom there now and is a wonderfully cheery sight.
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PUBLICATIONS PAR EXCELLENCE
Two new publications are now available for Ohio horticulturists and gardeners.
* "Landscape Plants for Ohio" is 40 pages of color photographs and descriptions of trees, shrubs and ground covers, from Acer campestre to Wisteria floribunda. Also included are plant selection tips, plant installation and care suggestions, and a cold hardiness zone map. Plant descriptions include popular cultivars, size and form information, ornamental features and site considerations. "Landscape Plants for Ohio" is a brand new publication of the ONLA and plant descriptions and photos were developed as part of the partnership agreement between ONLA and the OSU ENLTT.
Copies are sold in bulk (minimum of 50) to ONLA members at the following costs: 50-100 are $2.50 each; 101-300 are $1.80 each; 301-600 are $1.70 each; and 601 or more are $1.60 each.
Company imprinting is available for a fee. To order, contact Vivian at ONLA (614)-899-1195; (800) 825-5062; fax (614) 899-9489; (800) 860-1713; or onla.org
Individual copies can be purchased for $5.00 each from ONLAs BuckeyeGardening.com website.
* "Ornamental Plants: Annual Reports and Research Reviews: 2004." It is now here! This OSU publication, typically available in late January at the OSU Nursery Short Course and ONLAs Central Environmental Nursery Trade Show, was late this year. But, it is better than ever this year in all its 228 pages. There are plant evaluation trials from Springfield, Columbus, Cincinnati, and Wooster. There are great research articles such as Hannah Mather's article on retractable roof liner production, a number of turf insect and disease control studies, updates on insects such as emerald ash borer, gypsy moth, viburnum leaf beetle and periodical cicadas, and much more.
Even better, this publication is free! During the next few weeks, BYGL participants listed above will be getting some copies. In addition, you can also order from April Martin in Communications and Technology at OARDC in Wooster. Call 330-263-3780 or email martin.881@osu.edu to order.
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TRANSPLANT SHOCK ISSUES
Bare root plants especially suffer from transplant shock. However, in the spring, transplant shock on materials planted last fall and late summer that suffered from cold injury to the roots and crowns can be observed. Transplant shock with these materials occurs with ball and burlap (B&B) plants, bare root and containerized material.
Transplant shock refers to a period of reduced growth following transplanting. The impact of transplant shock is often worse in the first year; however, effects can occur up to three years after transplanting. Transplant shock can be expressed the same way root injury from cold is expressed. These effects are: plants flush much later than normal in the spring, growth is retarded throughout the growing season, increased susceptibility to root rot or other disease pathogens, shoot dieback and death (if severe enough).
Young roots are often on the outside edge of the container, or the ball with B&B, and the first injured by cold temperatures, that is why transplant shock shows up in the spring after fall planting because of injury to these young tender roots. Young roots are required for Ca uptake; however, Ca is necessary for young root formation. Once young roots are injured it is hard to correct the problem, plants flush later, show retarded growth, etc. Overwintering practices need to be sufficient to protect mature and young roots from injury especially when newly transplanted on to a site in the fall. Watering the plant in well in the fall can also reduce the impact of transplant shock.
Plants suffering from transplant shock and/or root injury may leaf out, but wilt and desiccate later, once the plant needs to draw on its conducting tissue (roots) to transport water. Other common winter injury problems found in inadequately overwintered plants are bark splitting, root kill, and collar injury.
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HOLY MOLEY ... OR IS THAT HOLY VOLEY?
Many homeowners are observing large numbers of raised ridges crisscrossing their lawns and raised mounds of soil from the excavation of these runways. Those lawn disfigurations and disturbed plant roots, are usually the extent of direct mole damage to the landscape. However, this is the time of year that many homeowners also observe dead and damaged shrubs in their landscape. Closer inspection reveals lower bark damage and gnawed roots. They also notice that bulbs planted last fall failed to appear. This damage is often blamed on moles as well.
However, moles do not eat plants (they are carnivores) but they can contribute indirectly to this damage by providing ready-made tunnels for VOLES (which are herbivores). These are the critters that are actually causing the plant damage. We might even say that the emergence of the PERIODICAL CICADA in many areas of the state has also contributed to that same damage. Those insects provided a ready food source for moles, which resulted in large numbers of moles this spring in those areas. This potentially increases vole problems by providing ready-made tunnels and hiding places for voles. Isnt nature fascinating?
The vole damage has not been limited to the landscape. Joe Boggs reported that a number of container-grown rose bushes in a cold frame were destroyed this winter by voles eating the bark off of their crowns, and to a lesser extent, their roots and stems. Hannah Mathers also related that she had a report from a nursery in the same area that had experienced similar vole damage to liners in their overwintering houses. The most unusual vole damage report received this spring came from Hal Kneen, OSU Extension Educator, Meigs County. In early March, Hal reported that voles had devoured a rather large quantity of ornamental spikes and seedlings of plants such as cabbage and peppers in greenhouses in his neck of the woods.
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BUG BYTES
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THE BORER BATTLE CONTINUES
In June of 2002, an exotic insect was detected and identified in southeastern Michigan. Today, the battle against the borer, the EMERALD ASH BORER (EAB) (Agrilius planipennis), continues in Michigan, Ohio, Indiana, and Ontario, Canada.
EAB eradication projects continue in Ohio in Lucas, Fulton, Henry, Wood, and Hancock counties. Updated findings maps, quarantine maps, and regulatory information can be found at the Ohio Department of Agriculture's website below.
It is estimated that this insect has killed nearly 15 million ash trees in Michigan, and continues to search for its next ash meal. Stay alert, keep your eyes open, and continue to monitor ash trees in your area. Check out some of OSU Extension FactSheets, including F-55-04, "Are My Trees Ash," HYG 2048-05, "Should I Treat My Ash Tree?," and HYG 2049-05, "Emerald Ash Borer Diagnostic Check-Off List" to assist you in monitoring efforts across the Buckeye state. A regional website is being developed and will provide users with the latest information and links to all states battling the borer. The factsheets mentioned above will be linked to this site. It should be posted within a few weeks.
The message of not moving firewood, Don't Move Firewood - It Bugs Me, is a uniform message that all three states want to continue to communicate to the masses. A USDA billboard campaign across northern Ohio, northern Indiana, and Michigan is slated for the spring and should be popping up on a highway billboard near many of you soon. EAB Awareness Week is the week of May 23, leading up to the Memorial Day holiday weekend (lots of travel).
Stay tuned to the BYGL as EAB will probably be a frequent flyer in upcoming BugBytes.
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DEGREE-DAY CRYSTAL BALL DIVULGES HATCH
Participants in the Cincinnati BYGLive! learned first-hand the value of using GDD to predict insect pest activity. Prior to embarking on their diagnostic walk-about, the participants gathered to review anticipated insect pest activity based on degree-days. See above information for accessing GDD websites. A print-out of the table of Phenological Events and GDD from the website indicated that the GDD for the BYGLive! location was 111. Notable phenological events that were listed included first bloom of star magnolia (83 GDD); first bloom of border forsythia (86 GDD); full bloom of corneliancherry dogwood (98 GDD); first bloom of Chanticleer Callery Pear (123 GDD); and egg hatch of ETC (EASTERN TENT CATERPILLAR) (Malacosoma americanum) (92 GDD).
Looking around, the participants observed that the plant phenological events certainly appeared to match the predicted events. After walking a short distance, they also discovered recently hatched first instar of ETC still clustered around their egg masses on a crabapple. As one participant noted, with the accuracy of growing degree days, it is tempting to become an armchair entomologist! Of course, the real lesson learned was how growing degree days allow for more efficient monitoring of plant pests and more cost-effective scheduling of pest management decisions.
In 2001, ETC captured national attention by being linked to Mare Reproductive Loss Syndrome (MRLS). The malady caused widespread loss of thoroughbred foals in Kentucky and cost the industry more than $336 million. The caterpillars prefer to feed on trees in the family Rosaceae, particularly those in the genus Prunus, such as cherries. They occasionally feed on ash, birch, maple, and oaks. As their name implies, these caterpillars eventually produce very obvious silk tents or nests at limb and branch forks. They live inside the nests, but carouse about the branches of their host tree feeding on expanding foliage. High populations produces rapid defoliation. Since loss of leaves typically occurs early in the season, trees must set out new leaves at considerable energy expense.
The nests currently are very small, and colonies can be easily eliminated digitally using "smash and/or smear" techniques. Less hands-on methods include an application of an insecticide, such as Bt (Bacillus thuringiensis) or other products labeled for caterpillar control. Make applications to plant foliage while larvae are small. Numerous predators and parasites also attack this pest, but in some years these agents do not arrive in sufficient numbers to adequately control tent caterpillars.
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BOXWOOD MAJOR MINERS
Cincinnati BYGLive! participants also observed heavy damage caused by BOXWOOD LEAFMINER (Monarthropalpus flavus) on the English versions of their namesake host plants. The yellow to orangish-brown leaf damage was severe enough to be seen from a distance, and could easily have been mistaken for winter injury, or possibly a nutrient deficiency. However, close examination revealed the affected leaves were riddled with blister-like leaf mines. Leafminer populations were so high that the mines had coalesced, allowing an easy parting of the upper and lower leaf epidermis to expose the legless, yellowish-orange leafminers. Some leaves had as many as 10 miners and virtually every leaf from last season was infested
The boxwood leafminer is a midge fly. Adults superficially resemble miniature mosquitoes; however, they have bright orange abdomens. Winter is spent as 3rd instar larvae (maggots) inside the blister mines. In the spring, larvae continue to feed, develop through a 4th instar, and pupate by mid- to late April. Adults emerge from late April through early May. Shortly after emergence, adults mate and lay eggs to start the next generation. During the remainder of the growing season, the leafminer develops from egg hatch to 3rd instar larvae, to produce the mine in which they feed and overwinter.
Control options include an application of imidacloprid (e.g. Merit) made as a soil drench in the fall or very early spring prior to the plants breaking winter dormancy. This kills overwintering larvae, and the fall application limits leafminer damage to the plants. This strategy has proven to be very effective and will also control BOXWOOD PSYLLIDS (Psylla buxi). A more traditional approach involves applying acephate (e.g. Orthene) as a foliar systemic spray once egg laying is completed in the spring. However, timing of the application is critical and requires close monitoring of leafminer activity.
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UP YOUR NOSE THE MIDGE FLY GOES
As spring temperatures rise, so do billowing clouds of gnat-sized flies. These are midge flies and the clouds are mating swarms. Midge flies are grouped into several fly families representing a wide range of life styles, from the aforementioned leafminers, to gall-makers, to biting midges (e.g. no-see-ums). However, the swarms are NON-BITING MIDGES (Family Chironomidae).
Non-biting midges look like miniature mosquitoes and are around 1/8" in length. Adults are humpbacked, multicolored (many are tan to brown and gray), and males have large, feathery antennae. Most notably, both males and females lack the piercing/sucking mouth parts of true mosquitoes.
Swarms of these midges may appear as pillars of smoke mysteriously hovering a few feet above the ground and can be most easily seen when the sun is low in the sky. Some species are aquatic and swarms are found near or over water. Larvae of other species are terrestrial, but are associated with wet habitats that are rich in organic matter. Non-biting midges are considered beneficial as they consume algae, plankton, and decaying organic matter. However, when swarming masses of midges are encountered by cyclists or joggers, their beneficial status may depreciate as they disappear up a nostril.
Of course, the midge flies are not seeking nasal encounters, they are instead looking for love! Midge adults are short lived and converge at dusk to mate. The males gather in large swarms to await with amorous anticipation the arrival of females. The females attempt to fly through the swarms...use your imagination. After mating occurs, the females quickly drop their egg masses on or near larval feeding material. Both males and females die (happily?) shortly after mating. Larvae eat and develop for several weeks, then pupate to emerge as swarming adults.
There are no practical control options for these midge flies. The midges are a valuable source of food for bats, birds, fish, frogs, and other creatures, and they are important members of several types of ecosystems. Although the swarming cycles may repeat throughout the season, they are relatively short-lived events. The swarms are strictly a curiosity to see, or at most a moderate nuisance. Indeed, discussing what is going on with the swarms can create topics for conversation much more interesting than the weather.
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PINE WEEVILS WOBBLING
The warmth of spring and yellow forsythias summons the reminder to treat white pines, other pines, and spruces, for the WHITE PINE WEEVIL. After 2-3 days of temperatures around 65F, the adult females emerge from the duff under the trees, and climb to the leader of the favored host. Here, she chews a circle of holes around the top of the leader to bleed out the sap, then lays eggs in the leader, just above the area where the holes were made. Protected from being drowned by sappy goo, the legless larvae begin tunneling down the leader to the whorls of branches below. Left untreated, the leader begins to wilt and brown by July, causing the pine or spruce to produce multiple leaders, thus losing its shape.
Now is the time to treat preventively by drenching the base of the trunk with imidacloprid (e.g. Merit for commercial applicators, Bayer Advanced Tree and Shrub Concentrate for homeowners). However time is quickly running out, as the insecticide takes 30 days to circulate throughout the tree. Nurseries and Christmas tree growers can still use dimethoate and Dursban for this pest. Permethrin Pro, Astro or Onyx can be applied to the leaders of susceptible trees until mid April. For more information, refer to the PEST Newsletter or Dr. Dave Shetlars FactSheet on white pine at the website below.
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WHITE PINE DIAGNOSTIC CHALLENGE
Dave Leonard (Consulting Arborist, Lexington, KY) shared an interesting diagnostic challenge with participants of the BYGLive! in Cincinnati. Dave showed the group a section taken from the main stem of a white pine. The sample was about a foot long and 4" in diameter. It had two holes approximately 3/8 to 1/ 2" in diameter through the bark that lead to equal diameter tunnels bored into the xylem. The tunnels were bored straight into the xylem for about an inch, then turned 90 degrees to run parallel to the wood grain for the entire length of the sample. Within the tunnels were several distinct chambers, separated by thin panels of wood. Some of the chambers appeared to have cast pupal skins, and one chamber had what appeared to be a large ball of pollen grains.
The group offered several speculative identifications as to what type of wood-boring insect could have caused the damage. However, none of the common wood boring beetles or moths found on white pine matched the damage seen in the sample. That was, until Dave indicated the tree was dead! Armed with this important piece of information, several participants correctly identified the insect culprit as a CARPENTER BEE. The sample clearly showed how this wood boring insect behaved before people created lumber! In fact, the dead stem was nothing more than a two-by-four wrapped in bark.
In the spring, female carpenter bees drill perfect holes 3/8 to 1/ 2"in diameter into wood. The wood most commonly associated with this insect is in the form of exposed horizontal strips of cedar, pine, or fir wood used on or around buildings. Once inside the wood, the females turn 90 degrees and tunnel parallel with the wood grain for 6 - 10". As they tunnel, the females create chambers that they pack with balls of pollen grains stuck together with nectar. A single egg is laid on a pollen ball, and the resulting larva feeds on the ball until it completes its development in the fall.
Carpenter bees are commencing their spring activity. At this time of the year, overwintered females emerge and begin to construct their tunnels in wood. They may initiate new tunnels, or simply take-up residence in pre-existing carpenter bee tunnels. These big bees are often confused with bumblebees; however carpenter bees are black with a yellow thorax. They have a hairless, iridescent blue abdomen, instead of a fuzzy black abdomen like bumblebees. As the females busily tunnel and provision their wood chambers, the males have an annoying habit of buzzing back and forth around nesting sites, and occasionally dive-bombing unsuspecting homeowners. They are jealously guarding their mating territory. Although this behavior understandably causes alarm, it should be remembered that males lack stingers...they are all bark and no sting.
Carpenter bees seldom cause enough damage to produce structural weakening of the wood. However, one control option is to spray a pyrethroid insecticide labeled for home structural use into the openings and then plug the holes with silicone caulking. Follow the pesticide label directions closely and avoid direct contact with the insecticide. Another option is to replace heavily tunneled wood with fir. The bees appear to prefer cedar and spruce, with pine coming in second and fir a distant third. Also, unpainted wood is preferred over painted wood. A final and more entertaining control option is to apply the Wimbledon method: use a tennis racket, and pretend the bees are a fast serve. This approach does wonders to improve your backhand.
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DISEASE DIGEST
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BACTERIAL BLIGHT
Pseudomonas syringae pv. Syringae produces a variety of symptoms including flower blast, dead dormant buds, leaf spots, blackened leaf veins and petioles and shoot tip dieback, which appears as blackened stem cankers. The most susceptible genera include Cornus, Corylus, Vaccinium, Magnolia, Syringa, Pyrus, Populus, Tilia and Prunus. Control of bacterial blight on lilacs requires a copper spray program. Sprays of fixed coppers should be applied before bud burst. Two or three more applications at ten day intervals should follow but at a reduced rate. Too much copper, especially under slow drying conditions in the spring, causes severe leaf injury.
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TURF TIPS
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WHITE GRUB PROBLEMS?
Dave Shetlar reported concerns over several calls he has received recently in reference to how to control white grubs in turf early in the spring of the year. Apparently, Ricky Raccoon and Pepe La Pue are already digging up lawns in search of tender morsels to eat. Many homeowners and some professionals immediately associate this behavior with white grub infestations in turf. However, most species of white grubs have not yet returned to the soil surface from their overwintering depths in the soil to where they feed on the accumulation of organic materials that collect at the soil/thatch interface under turf. The exception is the European chafer grub. European chafer grubs feed longer into the fall than other species of white grub and return to the soil surface earlier in the spring. The range of this species of white grub in Ohio is relatively limited to the northeast portion of the state. The more likely candidates on which the raccoons and skunks are feeding are earthworms, but the recommendation is to do nothing. Earthworms are highly valued for their recycling of nutrients and organic matter in soils. Eliminating earthworms from lawns causes more problems than it solves.
Even if one discovers that the target of the raccoons and skunks is white grubs, management of white grubs in the early spring is not very effective. Though the grubs feed during the spring, they are quite large and the span of time for treatment is short. If a spring application is deemed necessary, check to make sure that the grubs are actively feeding at the soil/thatch level. Trichlorfon containing products (e.g. Dylox, Proxol) are the most effective pesticides at this time.
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TIME TO PRE-EMERGE!
It is not too late to apply a pre-emergent herbicide for crabgrass to turfgrass, thanks to the cooler temperatures and low soil temperature. Normally agronomists recommend applying pre-emergent from March 1-April 1 in southern Ohio, March 15-April 15 in Central Ohio, and early April to late April in the northern counties. However, the true demarcation is the soil temperature. Crabgrass begins to germinate once the soil temperature remains at 52-54F for 5 consecutive days, so the blanket of herbicide protection will still prevent most crabgrass seedlings from germinating. Remember to water the turfgrass after treating and avoid disrupting the turf once the herbicide is applied to maintain the layer of protection.
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INDUSTRY INSIGHT
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PHYTOPHTORA UPDATE
Phytophthora root rot is without a doubt one of the most serious pathogens in the nursery trades. Phytophthora is a name for a group of soil inhabiting fungi, which attack and kill a wide variety of plants. At this time of the year when new root growth is occurring, symptoms of phytophthora infections are expressed. Diseased plants appear to be lacking water, because the fungus is destroying their water conducting ability. The addition of water only adds to the spread of the fungus. Internal symptoms can be observed by removing the bark near the ground line. Diseased tissue is red-brown in color and sharply contrasted to healthy, whiter tissues.
If containers are recycled, dip each container in boiling water or steam treat. If dipped in chlorinated water, leave containers submerged for at least 10 minutes to kill all pythium and phytophthora overwintering spores. Always place containers on rock or gravel, or other well-drained sites. There are four products registered for chemical control, as soil drenches: Banol, Banrot, Subdue and Truban. Alliette is also registered as a foliage spray.
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CONIFER BLIGHTS
There are several conifer blights that cause losses in container beds, field plantings and landscapes with spring infections. Growers experiencing problems with foliar blights may be well advised to carry out a regular spray program in the affected fields or containers beds. For commercial uses, both copper oxychloride and mancozeb (Fore) have broad enough labels that they can be used without any fear of valid criticism. The most important time for application is from early spring until dry weather arrives. In container beds, irrigation schedules that minimize periods of leaf wetness are validated.
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APHID SCOUTING REMINDER.
April is a good time to begin your aphid-scouting program, especially if it's warm. Remember not to be too aggressive with the use of broad spectrum insecticides like Dursban, Sevin and some of the pyrethroids as these can
make spider mite problems worse later in the year.
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SHIPPING DETAILS
Spring shipping was off to a slow start in all parts of Ohio this year due to the poor weather conditions in March; however, most nurseries are into digging and shipping "full swing" now that April and warmer weather has arrived.
Whether you regularly ship plant material within Ohio, the United States or to foreign countries, or you are looking into the possibility for the first time, you should be aware that depending on where, how and what plant material you plan to ship, there more than likely will be specific restrictions.
When shipping within the US, or to foreign countries, you run into different quarantines, different paperwork and certification requirements, and other specific entry restrictions that must be followed. Realize as well, that shipping restrictions may change from year to year depending on the state, country and the plant material being shipped. There are several sources for the needed information to use when planning on shipping plant material:
* Ohio Department of Agriculture,614-728-6400, or www.ohioagriculture.gov
* American Nursery and Landscape Association, 202- 789-2900, or http://www.anla.org/
* National Plant Board: http://www.aphis.usda.gov/npb/law®.html (obtain the Federal and State Quarantine summary for the USDA, and all 50 states plus Puerto Rico)
ODA also has horticulturists (inspectors) available to review your shipping requests and determine any restrictions. They also have information on shipping from Ohio to other states, as well as receiving plant material from other states into Ohio. A license is a must in order for a grower to sell stock in Ohio and access inspector services.
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COMING ATTRACTIONS
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OHIO PLANT DIAGNOSTIC WORKSHOPS
There are a number of OSU Extension Ohio Plant Diagnostic Workshops coming up in May and June. Typically the workshops run from 10:00 a.m until 4:00 p.m., with several talks, a walking tour, and extensive discussions of diagnostic samples. Here is a list of upcoming dates to get on your calendar. More details to follow in future BYGL issues.
May 19: OSUE - Trumbull County (for Master Gardeners)
June 2: OSUE - Clark County (for Master Gardeners)
June 6: OSUE - Hamilton County (green industry and others)
June 8: OSUE - Lake County
June 24: OSUE - Franklin County (green industry)
June 29: OSU Secrest Arboretum, Wooster (green industry; one hour program)
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BYGLOSOPHY
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"I'm the Cat in the Hat, and I think that you need to come take a look at this thing called a seed. From the giant gum tree to this very small weed, every flowering plant started out as a seed. Plants are so useful to me and to you. Can you think of the ways? I will name you a few." You have to read the book to know the rest of the story! The Dr. Seuss book by Bonnie Worth is one of the best available to teach youth (and adults) about seeds and plants.
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