Pam Bennett, Barb Bloetscher, Joe Boggs, Jim Chatfield, Erik Draper, Dave Dyke, Dave Goerig, Tim Malinich, Amy Stone, and Curtis Young
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April 06, 2006
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This is the First 2006 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 04, 2006 conference included: Pam Bennett (Clark); Joe Boggs (Hamilton/Piketon); Jim Chatfield (Center at Wooster/HCS); Erik Draper (Geauga); Jane Martin (Franklin); Becky McCann (Agriculture Business Enhancement Center); Dave Shetlar (Entomology); Amy Stone (Lucas); Victor VanBuchem (HCS); 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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Kicking off this year's Weatherwatch are two tables. The first is a year-end summary of weather data from 2005. It provides an idea of how these five locations where the weather data equipment is located ended the year. Table 2 is the weather summary since January 1, 2006. For a link to the OARDC Weather Stations, check out: http://www.oardc.ohio-state.educenternet/weather.htm
Table 1. 2005 Summary
| 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 |
59.0 |
43.0 |
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N/A |
46.76 |
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| Hoytville |
NW |
61.1 |
39.8 |
50.4 |
49.8 |
37.32 |
33.27 |
| Columbus |
Central |
63.6 |
43.7 |
53.5 |
52.2 |
43.23 |
42.25 |
| Miami |
SW |
64.8 |
44.1 |
54.1 |
51.9 |
41.2 |
36.34 |
| Jackson |
South |
65.7 |
41.9 |
53.5 |
52.5 |
36.15 |
42.10 |
Table 2. January 1, 2006 to April 4, 2006 Summary
| 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 |
42.6 |
28.9 |
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N/A |
7.8 |
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| Hoytville |
NW |
43.9 |
27.7 |
35.5 |
30.0 |
8.59 |
6.54 |
| Columbus |
Central |
47.3 |
30.7 |
38.6 |
34.2 |
5.98 |
10.27 |
| Miami |
SW |
48.6 |
30.3 |
39.0 |
34.3 |
9.31 |
7.53 |
| Jackson |
South |
50.3 |
28.4 |
39.5 |
35.6 |
10.67 |
11.17 |
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HORT SHORTS
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GDD (GROWING DEGREE DAYS)
Once again we begin the growing season here on BYGL. By keeping track of growing degree days (GDD) at a number of locations around Ohio. The purpose for publishing these numbers here in BYGL is to emphasize the great differences in heat accumulations and its influence on plant and insect development within Ohio. At times, especially early in the growing season huge differences exist between what is happening in the southern part Ohio compared to the northern part of Ohio and sometimes this can also exist between the western and eastern sides of the state. We need to keep these differences in mind when discussing things that are happening in the landscape because everyone throughout the state is not experiencing these happenings simultaneously.
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 65 to 154. Following is a report of GDD for several locations around Ohio as of April 5, 2006: Painesville, 73; Cleveland, 74; Toledo, 65; Youngstown, 77; Lima, 71; Wooster, 87; Coshocton, 90; Columbus, 96; Springfield, 77; Dayton, 87; Cincinnati, 110; Ironton, 145; Portsmouth, 146; and Piketon, 154.
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; 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; and Apple serviceberry, first bloom, 159.
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PLANT PHENOLOGY
Signs of spring are unfolding daily across the state. Joe Boggs noted that forsythia (Forysythia spp.) in his area are close to full bloom, redbuds (Cercis canadensis) are showing color, and higan cherries (Prunus subhirtella) are nearing petal drop.
Pam Bennett noted that Corneliancherry dogwood (Cornus mas) was nearing petal drop and the following were in full bloom: forsythia, 'Red Sunset' and 'October Glory' maples (Acer spp.), flowering almond (Prunus triloba), daffodils and early tulips, and bloodroot. Star magnolias (Magnolia stellata) were just beginning to show color.
And last but not least, in the northern part of the state, Amy stone noted that crocus and other bulbs were emerging and Erik Draper said that the red maple (Acer rubrum) and Corneliancherry dogwood were just beginning to open.
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PLANTS OF THE WEEK
Read all about perennials and landscape trees and shrubs in the publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio" published by the 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 [http://Buckeyegardening.com] for $5.00. Click on "garden store" and then "onla plant guides." ONLA members can purchase these in quantities at a reduced price at [http://onla.org]
*PERENNIAL PLANT OF THE WEEK. Bulbs! It is the time when the long-anticipated work that occurred last fall finally pays off. Spring bulbs are emerging and blooming every day and are a true sign that winter is almost over. In central Ohio, daffodils and squill (Scilla siberica are in full bloom at this time as well as the early blooming tulips. Winter aconites are just finishing up their blooms and snowdrops have been long gone. After the blooms fade, cut them off and allow the foliage to remain until it dries for best results next spring.
*WOODY PLANT OF THE WEEK: Forsythia - Forsythia bloom is as erratic as the weather around Ohio this spring. In some areas of the state there is bloom only at the base of the plants, where snow or mulch protected them. In other areas, forsythia is in full bloom. Here is a look at an overall profile. Forsythias (Forsythia x intermedia and other hybrids) are highly popular, sunny-yellow flowering shrubs (5-10' tall) with excellent adaptability to most soils and good urban landscape tolerance. Plant them in full sun in mass plantings and shrub borders. Good for forcing cut stems to bloom in indoor arrangements in late winter. Many cultivars are available, including 'Lynwood Gold' and 'Spring Gold' which have been selected for dense flowering. 'Meadowlark' and 'Northern Sun' were selected for their cold hardiness and 'Arnold Dwarf' was selected for its low habit (3' by 7').
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A SWEET SEASON FOR SYRUP
Erik Draper reported that it has been a very good season for crazed collectors of sugar maple (Acer saccharum) sap. The typical sugarbush, the name given to a grove of sugar maples growing together, consists of maple trees that yield buckets of sap averaging 2-2.5% sugar. Therefore, these sappy collectors boil down or condense about 48 gallons of the clear dripping liquid in order to produce just one gallon of the finest, pure maple syrup! Sugarhouses are specialized structures with large ventilated roofs which hold an extremely hot, wood-fired evaporator used to quickly boil off 47 gallons of water. The resultant quality of syrup depends upon the skill of the operator, as well as conditions during the maple season and the time during the season when the sap is collected.
Temperatures are responsible for sap flow and the best flows occur when temperatures fluctuate between below freezing at night and rising up to 40-45F during the day. When warmer temperatures occur (50-60F), tree buds begin to swell and develop. As buds begin to develop in the spring, the syrup tends to become darker and develops a noticeable "woody" or "tangy-bud" flavor. Other maples, like reds, silvers, blacks or Norway's, may also be tapped and used; however, sugar maples have the longest period of sap flow before buds develop. Sugar maples also have the best tasting sap, as attested to by millions of pancake eaters.
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BUG BYTES
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EMERALD ASH BORER UPDATE
Since the last BYGL of 2005, many changes have occurred in the world of emerald ash borer (EAB) (Agrilus planipennis). The following is a recap and background information, and then highlights of some of the changes. There are also links along the way for readers to obtain additional information.
EAB is an exotic beetle that was discovered in southeastern Michigan, near Detroit, in June of 2002. It is thought that the insect arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating from Asia. Experts believe that the insect arrived 8-10 years prior to its discovery.
EAB has also established itself in Windsor, Ontario, and was first found in Ohio in February 2003. The following year, the insect was detected in northern Indiana. New finds often lead to the expansion of the quarantine area to include those infested trees. The current Ohio quarantine includes: All of Williams; Defiance; Fulton; Henry; Lucas; Wood; and Sandusky counties; portions of Erie, Ottawa, Hancock, Huron, Lorain, and Auglaize counties; the entire state of Michigan; and infested Indiana counties including Adams, Hamilton, Huntington, LaGrange, Marion, Steuben, and Randolph Counties. A map of the quarantined area and information on regulated items can be found at: [http://www.ohioagriculture.gov/eab/]. It is important to remember that quarantine lines change as infestations are detected in unregulated areas outside of the leading edge. Be sure to stay tuned for updates.
On February 15, of this year, Governor Bob Taft announced a change in Ohio's EAB program initiatives, in response to limited federal funding for 2006. The revised program now focuses on the containment of the ash tree-killing pest to northwest Ohio through quarantine regulation, statewide detection, and when funding is available, eradication efforts of extreme outlier infestations.
Last year, Taft supported the President's proposed $32 million EAB budget for 2006, knowing Ohio alone would need at least $24 million. The federal agriculture appropriations budget however, allotted only $10 million this year for the entire regional program which funds EAB efforts in Indiana, Ohio, and Michigan. To date in 2006, Ohio has received $1.25 million in federal funding for EAB efforts.
Due to the limited federal resources, Ohio Department of Agriculture (ODA) has revised its strategies and developed containment plans focused on the following areas:
*Regulation and enforcement of state-quarantined areas. It is illegal to move nonconiferous firewood and ash tree materials out of quarantined counties. Violators face fines of up to $4,000.00. Businesses and individuals that have regulated items (i.e. logs, firewood, and/or ash material) that need to leave a regulated area may want to contact ODA to learn more about a compliance agreement. It is important to note that there are requirements as far as the timing of the movement and proper disposal of material. ODA will be able to answer any questions that you have regarding compliance agreements and can be contacted at 888-OHIO-EAB.
*Statewide monitoring efforts, emphasizing an expanded detection tree program. Detection trees, ash trees that are girdled to attract EAB adults in an already infested area and are later cut down in search of larvae, are key in monitoring and early detection efforts. State officials aim to set more than 15,000 detection trees across the state before adult emergence begins in May. This compares to 1,800 detection trees established in northwest Ohio in 2005 whose objective was to determine the leading edge of the natural spread of the insect. This means that this year, wherever you are in Ohio, there are sure to be detection trees in your area. The objective of this years detection tree program is to have a better handle on where this insect might be across Ohio. Outlier populations have been the result of the artificial movement of infested ash material by humans.
*Eradication of extreme outlier infestations, aiding in EAB containment to northwest Ohio. Outlier infestations will be addressed as federal funding becomes available. Current priorities are the southernmost and easternmost points of infestation. Current eradications in Delaware and Auglaize counties are being paid for with monies from 2005 and will be winding down as the adult flight season is quickly approaching.
*Statewide educational efforts through private and public partnerships, focusing on detection and halting the artificial movement of EAB. This includes billboards, road signs, campground signage, other outdoor messages and outreach events, mailings, public service announcements and more.
In addition to the changes mentioned above, OSU Extension members of the OSU ENLT Team, in consultation with ODA officials, have developed the following two sets of pesticide recommendations for EAB - one for the contiguous quarantined area of northwest Ohio, and another for the rest of the state.
Within quarantined areas, there are several insecticide options available for people in northwest Ohio who elect to treat their trees, including systemic insecticides that are applied as soil treatments, trunk injections or trunk implants, as well as protective sprays that are applied to the trunk, branches and foliage. Some formulations can be purchased and applied by homeowners, while others can be applied only by professional applicators.
It is important to note that insecticide applications will have to be done annually, and in some cases, it may be more cost effective to remove and replace the tree. It is also important to realize that, while some treatments appear promising, success is not assured. Trees have continued to decline from EAB attack despite being treated over successive years in some research trials. In other trials treatments have failed completely. This inconsistency of control, coupled with the fact that insecticides cannot prevent emergence and spread of insects from trees that are already infested, is why insecticides are not used for eradication.
For those outside of the quarantined area, it is important to maintain perspective on the problem and stay updated and alert. Given the current status of the infestation, and the continued policy of the "Cooperative Emerald Ash Borer Program" to eradicate infestations that are detected outside the quarantined areas of northwest Ohio, insecticide treatments are not warranted and cannot be justified throughout the rest of Ohio. If additional monies are made available, eradication efforts outside of the quarantine will continue.
A fact sheet describing chemical treatments is currently being finalized and will be available very soon. BYGL readers will be alerted to its availability as soon as it is posted to the web and available in local county Extension offices.
Stay tuned to more updates including woodland and urban tree management plans.
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MAGGOTS IN THE LANDSCAPE: CRANE FLIES AND MARCH FLIES
Dave Shetlar reported that he has been receiving a number of inquiries about accumulations of robust maggots (larvae) in turf and mulched bedding areas from Kentucky, Ohio, Pennsylvania and New York. The types of maggots found are not your typical white house fly maggots but grayish-brown, heavy-bodied maggots 1/2" to 1" in length. These maggots are the offspring of either March flies or crane flies. Another term that is used to describe them is LEATHER JACKET. Typically the areas in which the critters are found in the landscape are moist to wet and rich in organic matter. Dave suspects that turf specialists and Extension educators might receive a lot of calls about these maggots this year as a result of a build up of dead turf (organic matter) from the impacts of billbugs and drought last year. When soaked by rains in the fall and spring, this decaying organic matter is highly attractive to the adults of crane flies and March flies. They may lay many eggs into concentrated areas resulting in the development of rather large populations of maggots in those spots. One point to emphasize here is that both the crane fly and March fly larvae are there to consume the decaying organic matter left behind after some other cause killed the turf.
With that said, there is a possibility that the turf could be damaged or killed by a crane fly. A couple of introduced species can cause problems in turf. These are the European species of crane flies that have caused major turf problems in the Pacific Northwest. The European species (Tipula paludosa and T. oleracea) feed directly on the living grass leaves and crowns and large populations can destroy well maintained turf. Recently, these species were also detected in Ontario, Canada in the 1990's and in 2004 they were discovered to have moved into the Buffalo, New York region. However, surveys in Ohio and surrounding states have not yet detected these foreign invaders, so any crane fly larvae found in Ohio are most likely native species.
There are several dozen native crane fly species that commonly infest turf that has been killed by white grubs, billbugs, disease, or inundation by water (wet sites) in Ohio. Like the European species, there are spring-flying and fall-flying species, so dead turf can be infested at either time. Fall-emerging species lay eggs in October that hatch within a week or two. The tan larvae hatch and feed during the fall until the ground becomes frozen. These larvae finish their development in the spring, often attaining a length of slightly more than one inch. By June, these mature larvae dig into the soil when the weather turns hotter and dryer. These larvae hang out until the fall, at which time, they pupate and emerge as adults. Spring-emerging species lay eggs in late April through May. Their larvae feed into June and may continue feeding during cool and wet summers or they go into a summer dormancy until the fall rains return. They then finish most of their feeding by the time the soil freezes. In March and early April, these larvae pupate.
Since there are numerous species of crane fly in Ohio, it is not uncommon to find lots of crane fly larvae within or under dead turf that remains in the spring. They are not the cause of this dead turf, but are taking advantage of the food.
March fly larvae are much smaller than crane fly larvae, but these larvae also feed on decaying plant material. One can often find dozens of them balled together under patches of dead turf. These flies emerge in May and early June in Ohio. The adults commonly lay eggs under piles of grass clippings or in thatchy turf. While the larvae generally feed on this decaying plant material during cool and wet periods of the year, there is a fair amount of evidence that the larvae may actually damage living grass stems and roots when they run out of decaying organic matter.
Since the European species of crane flies have not yet been detected in Ohio, there are currently no recommendations to apply controls when crane fly larvae are discovered. However, Dr. Dave Shetlar and Dr. Curtis Young are both interested in hearing about infestations of crane flies in turf. Dave is interested from the perspective of the turfgrass entomologist specialist for Ohio and Curtis is interested because he is conducting insect surveys of exotic pests in Ohio including looking for European crane flies. Please contact Dave or Curtis if you find crane fly larvae in turf.
If you need to preserve specimens, drop the live larvae into boiling water for about a minute, and then place the larvae into alcohol to preserve them. Send an e-mail to Dave [shetlar.1@osu.edu] or Curtis [young.2@osu.edu] to get instruction for shipping, delivery or pickup.
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FOREST TENT CATERPILLAR PREDICTION
Participants at the Cincinnati BYGLive! held on Monday at Spring Grove Cemetery and Arboretum discussed the large number of overwintered forest tent caterpillar (Malacosoma disstria) egg masses found on trees in southern Ohio and northern Kentucky. Is this a portent of things to come?
Last season, localized high populations of this general defoliator produced noticeable leaf loss to trees in southern Ohio and northern Kentucky. The caterpillars feed on a wide variety of deciduous trees including ash, sweetgum, oak, birch, cherry, aspen, elm, basswood, and sugar maple. Baldcypress also serves as an occasional host.
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 with 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 feeders.
Forest tent caterpillars have short grayish-white hairs and distinct white markings running down their backs. These markings have been 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 back.
The high numbers of egg masses indicate populations may again be significant this coming season and noticeable defoliation may occur. Eggs usually hatch in mid- to late April in southwest Ohio; however, defoliation may not become evident until the caterpillars reach late instar stages. Trees should be closely monitored. Effective treatments include the naturally occurring bacterium, Bacillus thuringiensis (Bt), applied to early instar stages, as well as other insecticides listed for general caterpillar control in the OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" http://ohioline.osu.edu/b504/index.html.
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HOME INVADERS RE-EMERGE
Several BYGLers reported that they are getting phone calls regarding a number of home invading nuisance insect pests. The home-crashers include: BOXELDER BUGS (Boisea trivittatus); WESTERN PINE CONE LEAFFOOTED BUGS (Leptoglassus occidentalis); and most notorious of all, MULTICOLORED ASIAN LADY BEETLES (Harmonia axyridis). Seeking a cozy place to spend the winter, these insects actually invaded the walls of homes in the fall. As spring temperatures warm, the insects attempt to reverse their direction and exit to the outside. However, confusion occasionally reigns and miss-directed, overwintered insects emerge into the home.
Boxelder bugs are 3/4" in length, narrow, and flat-backed. They are dark brownish-black and have three red stripes running lengthwise on the pronotum, the area behind the head. The bugs spend the growing season sucking sap from the leaves, tender twigs, and developing seeds of their namesake. As fall temperatures cool, they may appear in large numbers near overwintering sites, which include cracks and crevices in foundations, openings around windows and doors, and gaps beneath siding.
Adult western pine cone leaffooted bugs are 1/2" to 3/4" in length. They are light brown in color with patches of reddish-brown highlighted by yellow markings. The bugs are named for the flat leaf like structures found near the end of the hind legs. In Ohio, these insects prefer to feed on Scotch, pitch, and red pine cones. Homes near high concentrations of these trees may be more likely to experience a visit from these footloose nomads.
The multicolored Asian lady beetle's habit of invading homes in the fall may seriously challenge this insect's "beneficial" status. This introduced predator tends to congregate on homes and other buildings in the fall and with little inducement, the aggregations may move inside. This good-lady-gone-bad has become a familiar nuisance pest in many Ohio homes.
Although both the Boxelder and leaffooted bugs sport unusually long sucking mouthparts, they are not a threat to homes or homeowners. Likewise, the Asian lady beetle poses no threat to home structures or furnishings. However, the lady beetles are meat-eaters and they occasionally try to sample unsuspecting homeowners to assess their potential as a giant food item. The lady beetles cause no harm as long homeowners do not act like aphids.
The best way to deal with these home invaders is to prevent them from gaining entry in the first place. Wait until late spring to make sure these insects have left the home, then find and seal off entry points such as cracks around windows, doors, or utility pipes. Poorly attached home siding and rips in window screens provide an open invitation. Check homes for unprotected vents, such as bathroom and kitchen vents, or unscreened attic vents. In addition, while in the attic, look for openings around soffits.
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SPRUCE SPIDER MITE DAMAGE PERSISTS
Joe Boggs reported that he is receiving phone calls concerning spruce spider mite (Oligonychus ununguis) feeding damage observed on a number of conifers. However, this cool-season mite has yet to hatch from overwintered eggs, so the damage currently observed occurred either last spring or last fall.
Hosts of this mite include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, true firs, and sometimes other conifers. The mites feed by rupturing individual cells of the host's foliage, producing characteristic tiny yellow spots, or "stippling." As the stippling coalesces, foliage becomes bleached and eventually bronze-colored. Inner foliage is generally affected first.
Rainfall can have a significant impact on population numbers and the subsequent damage produced by this mite. Heavy rainfall reduces populations by washing mites from the needles. Conversely, long periods of dry weather allow numbers to build rapidly and substantial damage to occur.
As spring progresses, it is important to monitor for this tiny mite, and a "beating tray" is the most effective tool for discovering and assessing mite populations. This tool can be a purchased piece of equipment or simply a stick and an 8.5" x 11" tablet of white paper. No matter what you choose, the idea is the same. Hold the white target beneath the conifer foliage and strike the foliage several times with a stick or rod causing the mites to drop onto the white target. Next, tilt and lightly tap the collection paper or tray to allow plant debris to fall off.
Look closely for small, slow-moving dots, not much bigger than the period at the end of this sentence. These are the spider mites. The faster moving dots are likely to be predaceous mites, the good guys that feed on the spider mites. A finger can be used to "smash and smear" the mites to further help distinguish the good mites from the bad. Greenish-brown streaks are "pate de spruce spider mite."
Effective management efforts include simply washing (syringing) mites from the foliage using a heavy stream of water, applications of soaps and oils, or applications of traditional miticides. Syringing conserves predaceous mites, but may be a difficult endeavor on large trees. Soaps and oils are also kind to predators, but oils wash away the blue color on Colorado blue spruce.
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TURF TIPS
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SPRING INTO LAWN CARE
As the temperatures begin to climb and buds begin to swell, turfgrass greens up and thoughts turn to... taking care of that dang lawn. Lawn care can be very successful or a disaster, depending upon whether a few horticultural principles are ignored or followed. Following are recommendations for spring lawn care practices that lead to a quality stand of turfgrass.
*Soil pH - Start with a soil test to determine whether the soil pH is too low (acid) or too high (alkaline or basic). Most turfgrass species prefer to grow in soils with the pH between 6.2 and 6.8. Do not add lime just because Dad always added lime in the spring and it seemed to work. Find out if you really need to be adjusting the pH of the lawn.
*No Rolling - Rolling home lawns in an effort to even them out or make them smooth is an antiquated practice and only serves to compact the soil, causing more problems for turfgrass. Yes, golf courses do roll their greens and fairways; but, these areas are usually composed of sand and they also core aerate these areas numerous times each year Compaction due to rolling the lawn results in decreased oxygen available to roots, which in turn, decreases the turfgrasses ability to root and grow. The lack of pore spaces in the soil also decreases water movement or drainage through the layers of soil and turf doesn't do well in water puddles.
*Cutting height and frequency - Two of the easiest ways to weaken and ruin lawns are mowing infrequently and mowing too low. Often in springtime, people try to mow only on nice sunny days and when all of the grass is dry. This may lead to only having to mow once every 2-3 weeks, which is big MISTAKE. It is better to mow wet grass than allow it to grow too high and then cut off too much of the green photosynthesizing tissue.
The complete or almost total removal of all the green is affectionately known as scalping and severely weakens the turf. These scalped areas are perfect for allowing weeds and crabgrass to move in and begin to compete with the turf.
Sharpen the mower blades and never take off more than one-third of the total height of the grass. If the grass is 3" long, then only 1" of turfgrass should be removed. Turfgrass in home lawns should never be mowed less than 2" because there is a direct correlation between root mass and shoot length. More roots mean healthy and vigorous turfgrass plants, which are then more capable to cope with the stresses.
*Repairing dead spots -- When filling in the dead spots, try as much as possible to match the species to what is already there. If you mix species, like fescues with ryegrass, ryegrass with bluegrass, etc., you may end of with a "patchwork quilt" effect in the lawn.
When seeding, prepare the soil for best results. Rough up the dead area to make good soil-to-seed contact and use a light mulch, like straw, to keep moisture available for the tiny seeds and seedlings. Remember, if you intend on repairing spots in the lawn, do not use crabgrass-controlling herbicides on the lawn. These crabgrass herbicides cannot distinguish between bad grass seedlings (crabgrass) and good grass seedlings (turfgrass), they prevent all grasses from growing! Select a crabgrass pre-emergent product that contains siduron that is safe to use on newly and recently (last fall) seeded lawns.
*Herbicides for weed control - In order to control the majority of the broadleaf lawn weeds that can occur in a lawn, the absolute best time to control them is when they begin to bloom. This is usually toward the mid- to end of May. To effectively kill most of the lawn weeds, the weeds must be actively growing. This means that weeds under stress will not absorb or translocate chemicals unless conditions favor weed growth. Be careful when using these broadleaf herbicides because they do not distinguish between bad plants (weeds) and good plants (tomatoes, grapes) in the garden or in the flower beds.
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WINTER ANNUALS REAR THEIR UGLY HEADS
Joe Boggs reported that a number of winter annual weeds are blooming in lawns in southwest Ohio. These include: HENBIT (Lamium amplexicaule); COMMON CHICKWEED (Stellaria media); and HAIRY BITTERCRESS (Cardamine hirsute). Winter annuals germinate in late summer to early fall, grow through the winter, and flower and produce seed in the spring.
Their life cycle presents a serious problem to lawn weed management programs since pre-emergent herbicides that may suppress these weeds are most often applied in the spring to target summer annual weeds (e.g. crabgrass). Adding to the challenge is that some winter annuals, such as hairy bittercress, may also behave as summer annuals.
As with most turfgrass weeds, winter annuals are opportunistic plants and are simply exploiting openings in lawns. They are generally poor competitors and fail to become established in thick lawns. Thus, the first line of defense is to work towards producing thick, healthy lawns. However, winter annuals may also exploit opportunities provided during lawn renovation or rejuvenation in the fall. For example, Joe noted that he is observing the heaviest infestations of henbit and hairy bittercress in lawns that were seeded last fall, and the grass plants have not yet fully matured. In such cases, the best option may simply be to give the new lawn a chance to thicken this spring before considering weed control options.
In older lawns, post-emergent herbicides applied now will kill winter annuals, hopefully before new weed seeds are produced. Pre-emergent herbicides that are labeled for the target weed and applied in late summer suppress the germination of winter annuals. However, fall is the best time to over-seed lawns, so product labels should be closely examined to make certain the herbicide will not suppress grass seed germination. Again, the best defense against winter and summer annual weeds, as well as many perennial lawn weeds is a thick, healthy lawn.
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INDUSTRY INSIGHT
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PRE-EMERGENT CHALLENGE
BYGLers located throughout much of Ohio noted that some lawns are in serious need of repair as a result of last season's heat and drought damage. In many cases, dead areas must be over-seeded. However, this is also the time of year when lawn management activities focus on applications of pre-emergent crabgrass control products.
Lawn care professionals should make certain that their pre-emergent crabgrass control products do not interfere with their own efforts, or the efforts of their clientele, to successfully re-seed and repair damaged lawns. Read the label carefully to make certain the active ingredient will not act as a pre-emergent herbicide on newly sown grass seed as well as crabgrass. Products that suppress grass seed germination provide a recommendation for when treated lawns can be re-seeded safely.
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COMING ATTRACTIONS
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UPCOMING OSU EXTENSION PLANT DIAGNOSTIC WORKSHOPS
A number of OSU Extension Nursery, Landscape, and Turf Team workshops are scheduled for the season. Topics at each of the workshops this year include the following and more: Emerald Ash Borer, Diseases and Insects du Jour, Dr. Dendro Diagnostic Case Studies, Digital Diagnostics, Clinic Catharsis Sample Sharing, and Diagnostic Walks. As the season progresses, additional topics will be added. A more extensive program will be developed for the two-day October 5-6 Ohio Plant Diagnostic Workshop for Clinicians.
Dates scheduled include: May 24 - ABE Center, Bowling Green, May 26 - Springfield, June 6 - Burton, June 8 - Wooster, July 10 - Columbus, September 13 - Canfield, and October 5-6 50th Ohio Plant Diagnostic Workshop for Clinicians - Wooster.
More details on registration will be included in upcoming BYGLs.
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BYGLOSOPHY
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"Passing courteous, but slow in speech, Yet sweet are spring-time flowers." (William Shakespeare - The Taming of the Shrew)
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