Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Jane Martin, Hannah Mathers, Pam Sherratt, Amy Stone, and Curtis Young
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October 06, 2005
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This is the twenty-seventh 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 October 04, 2005 conference included: Pam Bennett (Clark); Barb Bloetscher (C. Wayne Ellett Plant and Pest Diagnostic Clinic); Joe Boggs (Hamilton/Piketon); Jim Chatfield (Center at Wooster/HCS); Erik Draper (Geauga); Dave Dyke (Hamilton); Tim Malinich (Cuyahoga); Dave Shetlar (Entomology); Amy Stone (Lucas); Curtis Young (Allen); and Randy Zondag (Lake)..
Additional factsheet information on any of these articles may be found
through the OSU Factsheet Database (http://plantfacts.ohio-state.edu/)
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HORT SHORTS
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*** IMPORTANT NEWS
As the days shorten, so will BYGL ... in frequency, not length. There will be NO BYGL next week (October 13). The BYGL will return on October 20. The much anticipated, always exciting, annual BYGL survey will arrive on October 27. The survey is your opportunity to tell the writers what you think. Each year we look forward to the comments and appreciate everyones suggestions for improvements. After October 27, the BYGL will retreat to its doghouse for a long winter nap. The 2005 BYGL season went too fast, doggone it!
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PLANTS OF THE WEEK
Read all about perennials and landscape trees and shrubs in the new publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio" published by the Ohio Nursery & Landscape Association (ONLA). The descriptions and photographs of plants were provided for this new publication by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at Buckeyegardening.com for $5.00. Click on "garden store" and then "onla plant guides." ONLA members can purchase these in quantities at a reduced price at onla.org
* Ceratostigma plumbaginoides, (Plumbago or leadwort). This plant makes a great border adding color to the fall garden with the dark blue blooms as well as the foliage. It grows to around 8- 12" tall and is a spreading groundcover that blooms in September and October in central Ohio. In addition, it takes on a striking reddish fall leaf color.
* WOODY PLANT OF THE WEEK: Nyssa sylvatica (Black gum). This week‛s plant is a tree that may have the most spectacular reds of any fall foliage tree in the world-class fall foliage spectacle of our Buckeye State. Black gum, also known as sourgum is a medium-sized (30'-50') native tree, though it can grow much taller. In youth it is often regularly pyramidal in form but it often opens over the years. It has outstanding lustrous green leaves in spring and summer and fabulous fall foliage color with shiny bright oranges to intense reds. Sourgum thrives in wet sites.
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TIM'S TERRIBLE TREE PLANTING TIPS
On a recent street tree evaluation, Tim Malinich ran into a plethora of problems affecting the performance of newly planted trees. The visit brought to mind the following tree torturing tips:
- Plant deeply in heavy soil, cover with several more inches of heavy compact soil.
- Add 8" of mulch, then stake with wire or nylon straps around the trunk and leave it there long after the stake is removed.
- Don't forget to damage the bark during shipment and subsequent handling.
Should you desire to KEEP your or your client's investment for a long time, avoid the aforementioned errors. Plant with the trunk flare at grade level into a well prepared hole; never let mulch accumulate more than two or three inches deep; remove all wire baskets, burlap and twine; remove all stakes and ties after one season; and protect the trunk like it is the life blood of the tree (it is!).
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SEASONAL NEEDLE YELLOWING OF EVERGREENS
Every fall BYGLers are reminded of the need to trot out one of our favorite quotes from Wisconsin naturalist and conservationist Aldo Leopold. Namely, his eloquent quote regarding the normal seasonal inner needle yellowing of evergreen conifers such as pine and spruce. We get questions about why these inner needles are yellowing, browning and eventually dropping. Here is Aldo Leopold‛s answer:
* " Pines have earned the reputation of being evergreen by the same device that governments use to achieve the appearance of perpetuity: overlapping terms of office. By taking on new needles on the new growth of each year, and discarding old needles at longer intervals, they have led the casual onlooker to believe that needles remain forever green."
" Each species of pine [and spruce, and fir, etc.] has its own constitution, which prescribes a term of office for needles appropriate for its way of life. Thus the white pine retains its needles for a year and a half; the red and the jack pines for two years and a half. Incoming needles take office each June and outgoing needles write their farewell addresses in October. All write the same thing, in the same tawny yellow ink, which by November turns brown. Then the needles fall, and are filed in the duff to enrich the wisdom of the stand. It is this accumulated wisdom that hushes the footsteps of whoever walks under pines."
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EIGHTH ANNUAL BLUEGRASS BYGLIVE!
The Eighth Annual Bluegrass BYGLive! was held on Monday at Three Chimneys thoroughbred farm in the Lexington, KY area. Thanks to Larry Hanks (Pampered Properties, Inc., Lexington, KY), who organized the event, the program was an outstanding success. Participants were intrigued by research updates, courtesy of a cadre of University of Kentucky (UK) and OSU Extension specialists, and they were captivated by beautiful thoroughbred horses, courtesy of Three Chimneys.
Three Chimneys is a premier Kentucky thoroughbred farm, offering a range of services from "total care" boarding, thoroughbred development, to mare breeding. Their stallions are considered among the best in the thoroughbred world, and have included Triple Crown winner
Seattle Slew. Bluegrass BYGLive! participants were treated to a showing of Three Chimney's top stallions. Of course, the show was stolen by Smarty Jones, the farm's best known resident. The 2004 winner of the Kentucky Derby and the Preakness, two of the three legs of the Triple Crown, Smarty is the fifth richest American thoroughbred of all time.
The group moved from the awe inspiring " business end" of the thoroughbred horse industry to the cutting edge of turf and landscape research. Participants heard many research and Extension updates from UK and OSU Extension Specialists including: Dan Potter (UK, Entomology) on Japanese beetle management; John Hartman (UK, Plant Pathology) - bacterial leaf scorch research; Julie Beale (UK, Plant Pathology) - problems arriving at the UK Plant and Pest Diagnostic Clinic; Bill Fountain (UK, Horticulture) - tree management challenges; and our very own Jim Chatfield on apple scab of crabapples.
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BUG BYTES
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ETC UPDATE AT THE BLUEGRASS BYGLIVE!
Given the location of the Bluegrass BYGLive!, one of the most apropos research updates was presented by Bruce Webb (UK, Entomology). Bruce lead the ground-breaking research effort that connected EASTERN TENT CATERPILLAR (ETC) (Malacosoma americanum) to the equine disease known as Mare Reproductive Loss Syndrome (MRLS). The syndrome includes early fetal loss, late fetal loss, uveitis, pericarditis, and encephalitis. Simply put, the MRLS causes thoroughbred horse mares to lose foals. During the springs of 2001 and 2002, the central Kentucky horse industry suffered economic losses from this disease totaling more than $425 million dollars. During the spring of 2001, the early fetal loss was estimated at between 25-35%, with some farms experiencing a 60% loss of foals to MRLS. The average thoroughbred fetal loss per year is 3-5%.
Bruce updated the group on the detection and monitoring of the ETC baculovirus, Malacosoma americanum nuclear polyhedrosis virus (MaNPV). He reported the results of a recent survey of natural infection during a regional epizootic of the MaNPV baculovirus in ETC populations in central Kentucky. His team found that the mean percentage of ETC tents infected by baculovirus was 59%, and the mean percentage of larvae infected by baculovirus within diseased tents was 89%.
The rate and efficiency of infection appeared to be helped by two ETC behavioral traits. First, the caterpillars do not remain attached to a single nest within an infested tree. They will move from nest to nest. Second, the caterpillars lay down silk trails on twigs and branches which they use as "trails" connecting the nests. As infected caterpillars contribute to the silk trails, they also contribute baculovirus to the trails. Thus, an uninfected caterpillar can become infected by following the trails left by other infected caterpillars. And, infected caterpillars move from nest to nest, further spreading the virus. The devastating nature of the virus coupled with behavior of the caterpillars makes the MaNPV baculovirus an effective potential tool for suppressing ETC populations.
 
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RUDBECKIA ROUNDUP
Tim Malinich reported that Rudbeckia was the sample of the week in Cuyahoga county. Three samples were submitted from across the county. The stalks had areas of sawdust like material being exuded near their bases. Upon closer inspection the sawdust was actually frass being pushed out from holes in the stems. Splitting the sample revealed a larva chewing its way through the center of the of the Rudbeckia stem. Dave Shetlar reported that there are three culprits commonly found chewing through perennials: the lizard beetle, European corn borer or the common stalk borer. Control for any of these tunneling troublemakers is removal of the infested material before the larva completes its lifecycle. Destroying the offending insect in this manner reduces next season's population. Application of the systemic insecticide imidacloprid earlier in the summer will also control these borers, however it may affect nectar feeding butterflies and other pollinating insects.
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ANTS UNDER PLANTS
Pam Bennett observed large ant mounds beneath several perennials in the OSU Extension, Clark County Gateway Gardens. Soil was heaped high on the stems, and affected plants showed symptoms of dieback and decline. Pam excavated some of the mounds to collect the culprits for identification; however, the mounds she probed appeared to be abandoned. No insecticide applications had been made, so she could not account for the ant no-shows.
Dave Shetlar noted that the most likely culprits were either ALLEGHENY MOUND ANTS (Formica excectoides), or BLACK FIELD ANTS (F. subsericea). He indicated that frequent disturbances can cause both species to abandon their mounds and relocate to more quiet areas nearby. Both of these ants are relatively large with foraging workers measuring around 1/4" in length. Both are also associated with aphids, or other plant-sucking insects. The ants protect the sucking insects by fending off predators. In return, the sucking insects provide the ants with high energy carbohydrates in the form of honeydew.
Allegheny mound ants are one of the true mound-builders of the ant world. Their dome-shaped mounds may be several feet in diameter, and reach a dizzying ant-height of 30". Mound ants range in color from chestnut red, to black, to a combination of red and black. The ants are very aggressive, and they can use their powerful mandibles to deliver a noticeable pinching bite to a probing finger. However, their threat to people is inconsequential compared to their impact on plants. Mound ants are capable of killing small bushes and trees by injecting formic acid into wounds created by their mandibles. They use this capability to clear plants that shade their mounds. All vegetation, with the exception of large trees, may be killed within 40-50' of large, well-established mounds. They have a deserved reputation of being a serious nursery and Christmas tree production pest.
Black field ants are much less accomplished mound-builders. They form large, low-profile mounds of loose soil. These ants do not inject formic acid into plants, so they are not direct plant killers. However, they often heap soil over low-growing plants and they will pile soil high onto plant stems. Their plant-smothering mounds have been known to cause plants to decline and die. In particular, they are sometimes considered a serious pest of turfgrass. These large black ants are also very aggressive, and they will attempt to bite using their powerful, well developed mandibles.
Although both Allegheny mound ants and black field ants feed on honeydew producing plant-sucking insects, they are also very effective predators. The ants my be observed dragging (presumably kicking and screaming) their victims back to their mounds to be surgically dismantled for protein. Since both species are considered beneficial insects, management efforts should focus on plant protection. Both species of ants can be persuaded to move by repeated destruction of their mounds. If a more powerful management tool is needed, Dave Shetlar recommended hydramethylnon (e.g. MaxForce Ant Bait). This material has a commercial use label, and applicators should read closely and follow the label directions.
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IT'S AN IPS
Curtis Young reported that he discovered an unusual pine bark beetle infestation. While visiting the grounds of the Rutherford B. Hayes Presidential Center in Fremont, Ohio, he came across an area that was littered with the branch tips (3-6" long) of an Austrian pine (Pinus nigra). The needles on the branch tips were off-color, pale green. When he picked up a sample, he discovered sawdust coming out of small round holes and out of the broken branch end. Further investigation revealed that the tips were still being actively excavated by small red-brown beetles (3/16-1/4" long). The beetles also had an abruptly truncated, sloping tail-end, suggesting that the beetles were a species of bark beetle in the Genus Ips.
Ips bark beetles also called engraver beetles, are dark red-brown to almost black and 1/8-1/5" (3-5 mm) long. They are distinguished from other bark beetles by their scooped-out posterior with 4 to 6 spines on each side. The beetles in the Austrian pine samples had five spines, four were relatively large along the edge of the concaved butt-end and one very small spine toward the center of the back. The probable identification of this beetle would be the FIVE-SPINED ENGRAVER BEETLE, Ips grandicollis.
In southern U.S., Ips engraver beetles kill more pine timber than any other forest insect, with the exception of the southern pine beetle. Ips beetles usually attack injured, dying, or recently felled trees and fresh logging debris. Infestations are particularly common in trees weakened by drought or lightning strikes.
Typically, the five-spined engraver beetle attacks the upper portion of the trunk and out into the major branches. What appears to be atypical about Curtis's sighting is the fact that the beetles were out in the very tips of the branches. This could be an indication of the size of the population in the tree, and the extent of the damage that had already been done to the tree. The infested tree was very tall, crowded by several other non-coniferous trees, and had branches only at the very top of the tree.
The best management of these types of beetle infestations is to maintain good health of the trees. Infested trees should be promptly removed and destroyed to reduce the number of beetles detecting the "stressed tree" pheromone and flying to the site. Insect parasites and predators, woodpeckers, and weather provide some natural control. Chemical control may be used to protect pines in urban or high value areas, if a trees health is questionable.
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CATS IN THE PARSLEY!
Dr. Shetlar noticed varying stages of black, yellow and white striped caterpillars in the parsley and fennel patches at the Master Gardeners vegetable plots. Immediately identifying them as BLACK SWALLOWTAIL CATERPILLARS, Papilio polyxenes asterius, he collected a few then alerted an avid lepidopterist to save the rest from possible demise.
According to " Butterflies and Skippers of Ohio", the black swallowtail butterfly has been seen in every county in Ohio and is one of the few species that has actually benefitted by human intervention, as the caterpillars can eat any member of the carrot family, including wild and cultivated carrot, parsnip, Queen Annes lace, fennel, dill, anise and angelica. Adults can be found nectaring on alfalfa, milkweed, coneflower, clover and ironweed, and are also seen gathering around mud puddles. Two-three broods may occur in Ohio, with major peaks in June, July and August. Extreme cases range from April 4- October 24, however the black swallowtail caterpillars seen munching now will overwinter in the chrysalis to emerge next spring.
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Windshield Wipe
* Male Polistes spp. (paper wasps) are being kicked out of the nest at this time, as their services are no longer needed. Males can be identified by their curled, yellow antennae. These frustrated, hapless, slender wasps can be seen on goldenrod, Sedum spp., and other flowers flitting about, but not really doing any productive collecting. One might expect these desperate wasps to sting, however, remember that stingers are specialized ovipositors (egg laying apparatuses), and since males can not lay eggs, they have no stingers and therefore can not sting! Haha!
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DISEASE DIGEST
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BLUSHING RED DOGWOODS
As autumn approaches BYGL'ers noted the changing fall color of the native dogwoods (Cornus florida). Of course Jim Chatfield took great delight in pointing out the fact that we might all be admiring a fungus rather than true fall colors. Erik Draper also mentioned that if the tree had a two-tone effect, red on the bottom half and green at the top, chances are pretty good that it is... Powdery Mildew of dogwood (Microsphaeria pulchra). As discussed in previous issues of this year's BYGL, powdery mildew can create some interesting diagnostic dilemmas.
Powdery mildew on dogwoods and magnolinas creates a curious effect. Later in the season as the mycelium of the fungus grows on and over leaf and bud surfaces it appears as a white coating. In the early stages of infection, the white fungal growth is often difficult to see and very subtle even though symptoms of infection are severe. Leaves may be stunted, reddened, or have irregular reddish-purple blotches on them and are often puckered by mid-season.
Can powdery mildew create problems for these trees? John Hartman, Extension Plant Pathologist for the University of Kentucky College of Agriculture states "Although it would appear to weaken trees powdery mildew does not appear to be lethal. We have observed that under high disease pressure, flower production is decreased the following year." So, what can be done to help out the dogwood? Hartman said to avoid cultural practices that stimulate succulent growth, such as applying nitrogen fertilizer, heavily pruning and excessively irrigating. Also apply a light layer of mulch over the root system, prune out dead branches, and provide good air movement and light penetration by judicious pruning of nearby vegetation.
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TURF TIPS
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GRUBS BE GONE!
Dave Shetlar reported that the masked chafer grubs have almost finished feeding and are beginning to descend deeper into the soil for the winter. They will return early next spring to finish development, before pupating and emerging as adults in June-July. The Japanese beetle grubs are still in their 2nd instar and may continue to eat organic matter until the first frost, perhaps in 2-3 weeks.
This is important for people who are just NOW discovering patches of brown grass which, upon pulling at the turf, reveal the distinctive C shaped white grubs. Although Dylox (trichlorfon) can still be applied, it is only going to be effective for 1-3 weeks, depending upon the species of grub, and date when the grubs tunnel to warmer depths. It may be cheaper to water the turfgrass and allow it to re-root itself, as fall is the preferred time for turfgrass roots to grow! A fall application of a fertilizer containing 30-50% slow release nitrogen, and plenty of water will help the turfgrass regenerate roots and recover.
Dont assume that brown areas indicate grub problems. Tug at the brown areas, as if pulling up a carpet. If grubs are chewing at the root zone, the turfgrass will pull right up like a piece of carpet and the grubs will be evident. Other problems, such as drought, billbug damage earlier in the season, and weedy dormant grasses may also be contributing to the brown patches.
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INDUSTRY INSIGHT
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TOMATOES CRACKING UP
There are two types of fruit cracks or growth cracks which afflict tomatoes; specifically, concentric and radial. Concentric cracking produces circular splits or cracks around the stem end of the fruit. Radial cracks or splits begin at the stem scar and spread outward. It is possible to have both types on the same fruit. Cracking occurs when the internal cellular expansion of the fruit is faster than the expansion of the epidermis or skin. This differing rate of expansion causes the skin to tear or literally split apart. Cracking can occur at all stages of fruit growth but it is more common as the fruit begins to mature and especially as color change starts.
Most fruit cracking occurs as a result of rapid growth stimulated by high amounts of rain following a relatively dry period; however, there are other causes of fruit cracking. Wide fluctuations of the fruit temperature can also induce cracking. This is true especially when plants do not have enough foliage to cover and protect the fruit. Exposed fruits heat up dramatically from the direct sunlight. Then at night the fruit cools quickly and the temperature differential is greater than it would have been had the fruit been covered by leaves. The heating causes fruit expansion and the cooling causes contraction and the epidermis cells resulting in the cracks or splits. Succulent plants, those that are grown under a high nitrogen and low potassium regime appear to be more susceptible to cracking.
Tomato varieties also differ greatly in their susceptibility to cracking. Typically the more resistant a variety, the later in the maturation process fruit cracking may occur. The best control is to select tolerant varieties and try to reduce large fluctuations in the moisture content of the soil. Also maintain a good foliage cover over the fruit, because the exposed fruit may be more susceptible to cracking. Wide fluctuations in air temperature may also increase cracking so keep it cool and steady and just say no to fruit crack!
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SCALE MANAGEMENT
BYGLers discussed the management of a number of scale insects that were noted in BYGL this season. The "soft scales" that were spotted by BYGL-eyed observers included: CALICO SCALE (Eulecanium cerasorum); FLETCHER SCALE (Parthenolecanium fletcheri); EUROPEAN FRUIT LECANIUM SCALE (P. corni); COTTONY MAPLE SCALE (Pulvinaria innumerabilis) and the COTTONY MAPLE LEAF SCALE (P. acericola).
These are called "soft scales" because they are not covered by a hardened waxy shield. As with all soft scales, they insert their sucking mouthparts directly into phloem tubes and extract sugar water, along with essential amino acids. These scales void excess sugar water in the form of sticky "honeydew" that may rain down on twigs, branches, and leaves of their host plant as well as other plants growing beneath the infested host. The honeydew may become colonized by black sooty molds creating an unsightly mess.
These soft scales spend the winter in the third instar nymph (crawler) stage on the bark of twigs and branches. This stage has proven to be highly susceptible to soil drenches of neonicotinoid systemic insecticides such as imidacloprid (e.g. Merit, Marathon), clothianidin (e.g. Arena), and dinotefuran (e.g. Safari) made from September into November. Dave Shetlar noted that although we are in the middle this application window, all is not lost if the application is missed. Excellent results may also be achieved by making soil drench applications in late-June to early-July targeting first and second instar nymphs as they settle to feed on leaves.
Dave also reported that research results from Dan Herms (OSU, Entomology) indicate that soil drenches of dinotefuran (e.g. Safari) will provide excellent control of two notoriously difficult-to-control hard scales: OYSTERSHELL SCALE (Lepidosaphes ulmi), and PINE NEEDLE SCALE (Chioinaspis pinifoliae).
These are called "hard" or "armored" scales because the adult females cover themselves with a hard, waxy coating ("test"). This waxy shield is impervious to most topical insecticides. Consequently, insecticide applications have traditionally targeted first instar nymphs (crawlers), the stage that lacks the waxy covering. Of course, timing is critical. Dan's results showed that timing for dinotefuran soil drench applications is much less critical. Indeed, applications made during the crawler stage as well as when the covered stages were present provided equally effective results a nearly total elimination of the scale insects!
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COMING ATTRACTIONS
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AUTUMN DISCOVERY DAY: SATURDAY OCTOBER 8
The flyer for OSUs Secrest Arboretums Fall Discovery Day is subtitled this year "discovering the artful landscape." Its welcoming words include: "Join us on Autumn Discovery Day for fun and educational activities centered around Fisher Auditorium and Secrest Arboretum...on the Ohio Agricultural Research and Development Center Wooster Campus."
The event, in Wooster Ohio (northeast Ohio between Mansfield and Akron) includes plant sales and auctions, an art sale, a bug zoo, guided walks including the new Educational Pathway in the Arboretum, and a seminar titled "The Artful Garden" featuring the noted landscape design consultant and lecturer Bobbie Schwartz. For food, fun and free education for the whole family come to Wooster and OSU‛s Secrest Arboretum this Saturday from 9:00 a.m. - 3:00 p.m. For more information and directions, check out www.secrest.osu.edu
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BYGLOSOPHY
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"Just living is not enough," said the butterfly.
"One must have sunshine, freedom, and a little flower."
- Hans Christian Andersen
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