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
|
|
May 05, 2005
|
|
This is the fifth 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 May 03, 2005 conference included: Pam Bennett (Clark); Barb Bloetscher (Entomology, C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Joe Boggs (Hamilton/Center at Piketon); Jim Chatfield (Center at Wooster/Horticulture and Crop Science [HCS]); Erik Draper (Geauga); Dave Dyke (Hamilton); Tim Malinich (Cuyahoga); Joe Rimelspach (Plant Pathology, CWEPPDC); Pam Sherratt (HCS); 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/)
|
WEATHER WATCH
|
Temperatures remain chilly in Ohio. Many BYGLers reported seeing some snowflakes flying, as temperatures remain below normal. Frost and freeze advisories were issued across much of the state on Tuesday night.
Below are the weather summaries from selected OARDC weather stations across the buckeye state. The information is a summary of data collected from May 1 - May 4.
| Weather Station |
Region of Ohio |
Ave. High Temp F | Ave. Low Temp F | Ave. Temp F | Normal Ave. Temp F | Total Precip " | Normal Precip " | | Perry |
NE |
49.5 |
38.1 |
N/A | N/A |
0.19" |
N/A | | Hoytville |
NW |
51.1 |
32.0 |
42.2 |
58.9 |
0.02" |
0.29" |
| Columbus |
Central |
54.4 |
35.6 |
45.7 |
61.4 |
0.00" |
0.49" |
| Miami |
SW |
56.6 |
32.7 |
45.3 |
61.6 |
0.00" |
0.88" |
| Jackson |
South |
56.9 |
33.5 |
46.0 |
57.5 |
0.00" |
0.52" |
For additional information, or to see the locations of all of the OARDC weather stations in Ohio, check out the website below.
|
|
HORT SHORTS
|
PERENNIAL OF THE WEEK
Doronicum orientale - Leopardsbane. This early spring bloomer provides startling yellow color in the garden in late April and early May. The daisy-like blooms are held high on 12-15" stems and make a nice combination with forget-me-nots. Plants tend to deteriorate in the heat of the summer, so interplant with other perennials that have summer features. Magnificum' is a cultivar notable for its 2' tall stems and large blooms.
|
|
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: http://www.oardc.ohio-state.edu/gdd/
The range of GDD accumulations in Ohio from north to south is 139 to 339. Following is a report of GDD for several locations around Ohio as of May 4, 2005: Painesville, 139; Cleveland, 143; Toledo, 182; Youngstown, 170; Lima, 215; Wooster, 213; Coshocton, 232; Columbus, 245; Springfield, 251; Dayton, 287; Cincinnati, 339; Ironton, 337; and Portsmouth, 337.
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.
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; inkberry leafminer, adult emergence, 150; Sargent cherry, full bloom, 151; star magnolia, full bloom, 151; Allegheny serviceberry, first bloom, 153; Manchu cherry, full bloom, 155; Spring Snow crabapple, first bloom, 155; Apple serviceberry, first bloom, 159; spruce spider mite, egg hatch, 162; Bradford callery pear, full bloom, 164; Allegheny serviceberry, full bloom, 169; saucer magnolia, full bloom, 174; PJM rhododendron, full bloom, 178; boxwood psyllid, egg hatch, 179; weeping Higan cherry, full bloom, 179; Koreanspice viburnum, first bloom, 185; regent serviceberry, first bloom, 186; Japanese flowering crabapple, first bloom, 189; eastern redbud, first bloom, 191; gypsy moth, egg hatch, 192; Koreanspice viburnum, full bloom, 205; azalea lace bug, egg hatch, 206; Spring Snow crabapple, full bloom, 209; common flowering quince, full bloom, 214; birch leafminer, adult emergence, 215; Coral Burst crabapple, first bloom, 217; elm leafminer, adult emergence, 219; common chokecherry, full bloom, 221; alder leafminer, adult emergence, 224; honeylocust plant bug, egg hatch, 230; common lilac, first bloom, 234; Ohio buckeye, first bloom, 245; common horse chestnut, first bloom, 251; hawthorn lace bug, adult emergence, 253; hawthorn leafminer, adult emergence, 260; flowering dogwood, first bloom, 263; red buckeye, first bloom, 265; Blackhaw viburnum, first bloom, 269; imported willow leaf beetle, adult emergence, 274; 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; 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; and doublefile viburnum, first bloom, 353.
|
|
BUG BYTES
|
HATCHING OF GYPSY MOTH BEGINS
Pam Bennett observed first hatch of gypsy moth in Clark County over the weekend. The gypsy moth has been detected in 43 of Ohio's 88 counties. This insect event of first hatch has been observed to be closely timed with the first bloom of Eastern redbud (Cercis canadensis).
The Ohio Department of Agriculture (ODA) is monitoring hatch and population levels across the state and has Suppression, and Slow-The-Spread treatments scheduled in the following counties: Clark; Defiance; Delaware; Fayette; Franklin; Highland; Jackson; Logan; Madison; Meigs; Ottawa; Paulding; Pickaway; Pike; Seneca; and Union. For more information about these treatments, check out their website below.
|
|
SPUDS ATTACKED UNDERGROUND
Home gardens sometimes become infested with unusual insect pests. One example of this occurrence is the presence of WIREWORMS. Wireworms are the larvae of CLICK BEETLES (Family: Elateridae). Wireworms resemble a jointed piece of wire, thus their common name. Most wireworm larvae are hard, chestnut brown, smooth, varying from 1/2 - 1-1/2" in length when grown. Some species are soft, and white or yellowish in color.
In home gardens, wireworms will attack a number of different vegetables, including beans, carrots, beets, celery, lettuce, onions, sweet potatoes, turnips, potatoes, cabbage and mustard. They damage vegetables by puncturing and tunneling stems, roots and tubers which can then become colonized by opportunistic fungi and bacteria.
Management of wireworms can be difficult for the home gardener, as no pesticides are available. Depending on the species, wireworms require 2-6 years in the soil feeding on the roots of grasses and other plants to complete larval development. Crop rotation can help by moving susceptible crops to new locations, but many home gardeners have very little room to do so. Another technique is trap cropping, in which carrots are planted to attract the wireworm. Plant nearly full grown carrots every 3' in the garden, then pull the carrots every 2-3 days, remove and kill the wireworms, and replace the carrot. Pieces of potato may also effectively attract wireworms.
|
|
FOREST TENT CATERPILLARS BRIGHTEN THE DAY
Participants at this weeks special Cincinnati BYGLive! held in northern Kentucky at the Boone County Arboretum, were treated to an impressive collection of trees and shrubs, most of which were free of plant problems. However, all was not lost, thanks to a discovery in the surrounding woods. The group happened onto an impressive infestation of forest tent caterpillars (Malacosoma disstria) feeding on sugar maple.
Despite its common name, forest tent caterpillars construct only rudimentary mat-like silk nests on leaves or bark. The caterpillars are gregarious during early instar stages - indeed, the BYGLive! group observed colonies containing 100-300 individuals! The caterpillars remain in colonies during the day, and feed on leaves at night. When disturbed, they may spin down on silk threads. Later instar caterpillars disperse from the colonies and become solitary.
Forest tent caterpillars have short grayish-white hairs, and distinct white markings running down their backs. These markings have been variously described as looking like "foot prints," or as being "keyhole-shaped." The markings are flanked by cobalt blue lines running the length of the caterpillars bodies. The caterpillars are sometimes mistaken for other hairy caterpillars, such as EASTERN TENT CATERPILLAR (M. americanum), or GYPSY MOTH (Lymantria dispar). Eastern tent caterpillars have a distinct, unbroken white stripe down their backs. Gypsy moth caterpillars have 5 pairs of blue spots followed by 6 pairs of red spots running down their backs.
The caterpillars are general defoliators and feed on a wide variety of deciduous trees including ash, sweetgum, oak, birch, cherry, aspen, elm, basswood, and sugar maple. Baldcypress has also been listed as an occasional host. The caterpillars will do little feeding on red maple and sycamore. The caterpillars are capable of producing significant defoliation during population outbreaks. Last year, we reported localized high populations in southwest Ohio, with significant defoliation observed on baldcypress (BYGL 2004-08, 5/20/2004). This year, isolated pockets are being reported again in southern Ohio, as well as the central part of the state.
|
|
EASTERN TENT CATERPILLAR WANDERLUST
In BYGL 2005-01 (4/07/2005), we reported that participants at the April 4th Cincinnati BYGLive! observed freshly hatched EASTERN TENT CATERPILLARS (Malacosoma americanum). This week, BYGLers in southwest Ohio reported that larval development is nearing completion. Late instar caterpillars were observed leaving their nests in search of food after plundering their hosts. Where populations are high, the departing caterpillars left behind trees shrouded in silk.
The traveling caterpillars retain their distinctive, unbroken white stripe down the backs, however, their hairs typically develop a reddish-brown color. Their wanderlust behavior may present a caterpillar identification challenge since observers may not connect the crawling caterpillars with their abandoned tents found in the branch forks of trees. Also, the caterpillars may be found on plants that are not listed among its preferred hosts. When populations are high, marauding hordes may "suddenly appear" on surrounding vegetation and cause damage to unusual hosts. But more often than not, they fail to find usable plant material, and simply wander until pupation. Only one generation is known to occur per year.
|
|
ROSE SAWFLIES SLUGGING IT OUT
The distinctive "windowpane effect" caused by rose sawflies is now appearing on the leaves of their namesake in southern and central Ohio. Early instar larvae of three rose sawfly species will produce this characteristic damage. The species are: ROSESLUG (Endelomyia aethiops), CURLED ROSE SAWFLY (Allantus cinctus), and BRISTLY ROSESLUG (Cladius difformis). The larvae of these species are somewhat similar in appearance. They have black to reddish-tan head capsules, and their bodies sport some variant of a green color motif. Determining exactly which rose sawfly is responsible for the damage is more than an insect identification problem, it is essential to making effective management recommendations.
The pale yellowish-green roseslug feeds as a skeletonizer on the upper leaf surface. The lower epidermis is left intact, and eventually turns white. This produces the obvious "windowpane" symptom. The roseslug is not a true "slug-sawfly." The common name is based on the shimmering effect created by the sawflys semi-transparent body. True slug-sawflies shimmer like slugs because they cover themselves with their own excrement. Roseslugs only have one generation per season, so feeding symptoms are not long lasting. Plants quickly outgrow the damage making this sawfly the least significant of the three species. Indeed, damage caused by this sawfly seldom warrants control of this pest.
Curled rose sawfly larvae are dark green in color. They have rows of small white spots, arranged in bands around their bodies. True to their common name, the larvae curl when disturbed. Early instar larvae feed on the lower leaf surface, and produce characteristic skeletonizing damage with veins remaining untouched. However, they may occasionally leave behind the upper leaf surface, producing the "windowpane" damage similar to that produced by roseslugs. Later instar larvae consume entire leaves, leaving only the midvein. Mature larvae bore into the pith of pruned canes to pupate. There are at least two generations per season in Ohio, so this sawfly can cause recurring significant damage.
The bristly roseslug is pale green in color and closely resembles the roseslug, but as the name implies, it is covered with short, hairlike bristles. These bristles are difficult to detect without magnification. Early instar larvae feed as leaf skeletonizers on the underside of leaves. The upper epidermis is left intact, and eventually turns white producing the "windowpane" symptom that superficially resembles that caused by roseslug and curled rose sawfly. Later instar larvae feed between the main veins which produces holes in leaves. Plants covered with "see-through-leaves" is a good indicator of this pest.
Bristly roseslug is the most damaging of the three rose sawflies. It is a "season-long" pest, and may have as many as six generations per season in Ohio. Control requires multiple applications of foliar insecticides. Systemic insecticides may also require more than one application, depending upon the product.
|
|
WINDSHIELD WIPES
Joe Boggs reported that Cincinnati BYGLive! participants engaged in a prickly debate on the best time of the year to apply imidacloprid (e.g. Merit) to suppress the depredations of SPINY WITCHHAZEL APHIDS (Hamamelistes spinosus) on birch. Some pointed towards spring as working well (the Boggs faction), while others counter-pointed that fall was the best time (the Larry Hanks (Pampered Properties, Lexington, KY) faction)). Feeding activity by this aphid produces characteristic leaf corrugations on birch leaves which are becoming very evident in central and southern Ohio, as well as northern Kentucky, the scene of the BYGLive!
Dave Shetlar settled the thorny issue. On birch, the aphid spends the winter as an immature female. Dave noted that since the females feed heavily before overwintering, the best time to apply imidacloprid is in September to early October. Joe bristled a bit at hearing this recommendation, but was a good sport and declared: Larry 1; Joe 0 ... for those nettlesome individuals interested in keeping score!
|
|
DISEASE DIGEST
|
BOTRYOSPHAERIA DIEBACK ON VIBURNUM
Dieback of shoots on doublefile viburnum is common in landscapes now and in many cases this is due to infection by the Botryosphaeria fungus, presumably in conjunction with stresses, from earlier winter injury to summer drought stress. The first symptoms of the BOTRYOSPHAERIA DIEBACK is the wilting of leaves on affected shoots. As the disease progresses on the stem you can note the extent of damage by checking internal stem tissue for discoloration. Also note rough and cracked areas on the affected stems. Prune out the affected shoots back of the area that shows discoloration of the vascular tissue in the stem.
|
|
SHREDDED PERENNIAL RYEGRASS
Recently, perennial ryegrass (Lolium perenne L.) has been shredding. Some perennial ryegrass lawns with a whitish cast have actually been shredded by the mower. Many of the new perennial ryegrass cultivars do not shred as much as the older cultivars, for example, "Lynn" were so tough that getting a clean cut was like chopping down a redwood with a hand axe. At the moment however, some of the newer cultivars are showing some signs of shredding. This may be attributed to the unseasonably cold weather. To read this article in full, visit Ohio States Buckeye Sports Turf website below.
|
|
TURF TIPS
|
SPRING FERTILIZER APPLICATIONS
If a late season fertilizer application was made last Nov/December, the lawn should have had quick spring green-up and good color until around mid-April. At that time, most lawns will have been fertilized again in conjunction with the pre-emergent herbicide application. If the pre-emergent herbicide did not contain any nitrogen however, now is the time to apply fertilizer to maintain color and density. The recommended rate for spring is 0.5 lbs N/1000 ft2 with a proportion of the nitrogen from a slow release source.
|
|
APRIL SHOWERS CAUSE TURF SOURS
With the cool temperatures and copious amounts of rainfall, the anticipated diseases are appearing. PINK SNOW MOLD, caused by Microdochium nivale is showing its symptoms of tan patches with rusty edges, in shaded areas on golf courses. This disease continues as long as the temperatures hover below 65F and moisture is present.
Although it can develop on other grasses, it is most distinctive on short cut bentgrass and annual bluegrass. The pink snow mold which is being diagnosed presently, developed without snow, and forms patches 6-8", instead of the 8-12" experienced when the disease is under snow cover. Although golf courses may require a preventive treatment in the fall for this disease, high cut turfgrass will usually outgrow the disease, once the temperatures rise and the leaf blades are able to dry. Raking the patches and fertilizing with a slow release source of nitrogen will help to encourage new growth.
ANTHRACNOSE is mostly a golf course turfgrass disease that can kill annual bluegrass, if the fungus, Collectotrichum graminicola grows in the basal area. This disease is noticed when patches of grass turn a rusty orange-tan color. Close inspection of the grass will reveal blackened stems and crowns. In advanced cases, the grass plant may pull right out of the ground. The disease is diagnosed by finding black, spiny acervuli on the lower sheaths and crowns.
Because it is a root disease, basal rot anthracnose requires management with a combination of good management practices and preventive fungicide applications. Core aeration to open the root zone and regular applications of fertilizer to encourage growth will help to reduce the severity of the disease. Proper irrigation and providing good drainage are vital to manage this disease.
LEAF SPOT occurs mostly on high cut turfgrass, especially susceptible cultivars of Kentucky bluegrass. Leaf spot is a complicated association of several pathogens which attack the sheaths, crowns and leaf blades. Drechslera spp. begin to attack the leaves and sheaths of bluegrass in cool, wet spring conditions, causing elongated darkened lesions which coalesce and spread as the rainfall continues. These lesions envelop the sheaths, killing the leaves, which wither and turn brown. Gradually the area thins as the crown and roots succumb to the continual pressure on the plant. Helminthosporium sorokinanum becomes active in warmer temperatures, causing lesions on leaves and sheaths. These lesions also enlarge and kill the leaf blades from the lesions upward.
Although preventive fungicides can help to abate this disease, replacing the older susceptible cultivars with newer disease resistant ones is often the best remedy. Core aerating to improve rooting and applying a regular, balanced fertilizer containing 30% slow release forms of nitrogen will help to maintain steady growth. Regular mowing to avoid scalping and thus stressing the lawn will also help immensely to curtail symptoms.
|
|
INDUSTRY INSIGHT
|
CHINCH BUGS AND BILLBUGS
Dave Shetlar reported that these two turf pests are now active in Columbus, Ohio. Both chinch bugs and billbugs overwinter in the adult stage. When soil temperatures warm in the spring from 65-70F, the adults resume activity. In regard to plant phenological indicators, it appears that overwintered chinch bug and billbug adults resume activity when flowering dogwoods reach full bloom. At this time, adults begin to feed on grass, find mates and commence egg laying. Both insects may be observed wandering about on pavement, curbs, and sidewalks adjacent to infested grass. Thus, surveys of these areas can help to pinpoint potentially infested sites.
An ounce of prevention now, could be worth more than a pound of cure later, after damage is evident. Prevention of damage from either chinch bugs and billbugs, and can be accomplished now, by treating areas of lawns that showed damage from either of these two insects last year, with an insecticide which will kill the overwintered adults before they have time to lay eggs. The synthetic pyrethroid bifenthrin (Talstar) provides good control of the adults of both insects. In mid-May - early June, imidacloprid (Merit) performs well, and the higher use rates generally ensure that sufficient residual activity will remain to kill grub populations this fall. Check for the presence of either insect before applying the insecticide.
|
|
COMING ATTRACTIONS
|
May 2 PLANT DISCOVERY DAY- OARDC's 11th ANNUAL PLANT DISCOVERY DAY
Secrest Arboretum hosts this plant-oriented full day event in Wooster, Ohio on the OARDC Campus, Saturday, May 7, 2005 from 9:30 a.m. - 3:00 p.m.. The event has activities for the whole family including: the Famous Bug Zoo & Critters Up Close; a Rare Plant Auction, 11:00 a.m. - 12:00 p.m.; a Silent Plant Auction, 9:30 a.m. - 12:30 p.m.; and Research & Extension Exhibits in the Arden Shisler Center, 9:30 a.m. - 3:00 p.m.. For more information visit the arboretum's website at: http://www.secrest.osu.edu or call (330)263-3761.
|
|
The CHADWICK ARBORETUM PLANT SALE
begins Thursday, May 6th with a Friends Reception and auction at 6:30p.m.. Another auction is open to the general public at noon on Saturday, May 8th. Besides the wide assortment of interesting and unusual plants being sold Thursday- Sunday, a Silent Auction will be held Thursday evening - Friday at 6:00 p.m. Please plant to attend one or all three days of fun and fantastic deals!
|
|
BYGLOSOPHY
|
The grass may be greener on the other side of the fence, but you still have to mow it. - Anonymous
|
|
