The following articles were compiled during the last 7 days by members of the Extension, Nursery, Landscape, Turf (ENLT) team to benefit those who are managing a commercial nursery, garden center, or landscape business or someone who just wants to keep their yard looking good all summer. Access the BYGL website for additional information on other seasonal topics at: http://bygl.osu.edu
For more pictures and information, click on the article titles. To contact the authors, click on their names.
Authors Ashley Kulhanek
Published on May 3, 2019
For many, the lawn is a sacred place where nary a clover or dandelion dare venture. For others, lawns are becoming more diverse for the sake of bees, or for the sake of giving up on the battle against weeds. Dandelions and clover may be the first to pop to mind when considering lawn weeds, but this was the first time I had seen violets in turf.
From afar, the untrained eye may assume this purple hue in the lawn is creeping charlie, or dead nettle, both common weeds that carry a purple flower.
But upon closer inspection, these were violets! While I treated this as a pot of gold at the end of a rainbow, one of our turf professors shared that wild violets are actually one of the most notorious lawn weeds and are difficult to manage.
Violets (viola sp.) spread by seed and by rhizome. They come in shades of purple, white, and yellow. Some are bi-color.
Violets attract pollinators and are the primary host plant for the caterpillars of a group of butterflies known as fritillaries. Violets are also the sole food source for the mining bee Andrena violae a specialist bee that only visits violets.
Violets establish well in shady, moist areas where turf is not vigorous and cannot out-compete violets and other weeds. These areas often pose a challenge for turf establishment and so violets may be a welcome option for ground coverage. However, once established they can spread forth from that tough site into your desirable lawn areas.
Violets can also be a sign of thinning lawns overall, and can establish where lawns are mowed too short , competing with that lawns’ chances of growing thick and vigorous once more.
So what to do!?
Of course, the choice is yours! Should they stay? OR should they go? Those found at Chadwick seem to have become part of the display and were a welcome sight to frolic through this spring.
Should you desire to manage your violets in lawns, there are options. If a patch is caught early, it may be best to dig and hand pull them for control. Consider the conditions of the site as well. Is there the option to increase light penetration or create a thicker stand of turf to compete with weeds? Chemical control for violets include the use of post-emergent broadleaf herbicides containing the active ingredient Triclopyr. Two or more applications may be required to make an impact on established violets. Fall application when plants are directing energy to the roots is considered most effective. Even with a solid product, control of violets is difficult. They’re tough little things! When using pesticides, be sure to read all labels and follow instructions. The label is the law for use.
Lawn Talk University of Illinois
Authors Joe Boggs
Published on May 3, 2019
Sometimes we run across bizarre things in Ohio landscapes that simply defy explanation. Such was the case yesterday when I came across “tree moats” (sometimes called “mulch moats”) in a park near my home in the southwest part of the state. I’ve encountered this bizarre practice before and fail to fathom the logic.
As their name implies, tree moats are created by excavating a moat-like ring around trees or shrubs at about the dripline, or slightly beyond. This is done with an edger or a shovel. In either case, there always appears to be a concerted effort to sever roots growing beyond the excavation zone.
If a shovel was used, the excavated turf and soil is often piled over the root zone rather than carting it away. Of course, this can serve as a great foundation to create truly noteworthy mulch volcanos (more on this later).
What’s Wrong with This Picture?
Plants don’t have a cardiovascular system to ship oxygen to the roots. The root cells acquire oxygen directly from their environment. Piling soil on top of the root zone blocks oxygen from infiltrating the soil.
If the primary root system dies, certain trees have the capacity to form a “secondary” root system (even “tertiary”) from buds located on the main stem. However, this elevated root system growing into a mound of soil is subject to a number of tree-debilitating issues including moisture stress. Mounding soil enhances soil drying and the slopes can shed rainwater reducing water infiltration.
When roots reach the edge of the mound, they may turn back towards the main stem; the roots can’t grow into thin air despite needing oxygen! Eventually, these roots encircle the tree trunk and merge with the stem tissue. As these errant roots increase girth, they gradually girdle the trunk and restrict vascular flow. Thus, they are known as “stem-girdling roots.”
Cutting roots that cross the tree moats may harken back to the days when we thought that tree roots are confined to an area within the dripline. We also envisioned tree root systems as being mirror images of the canopy with the roots extending deep into the soil.
Of course, research has taught us that a tree’s root system actually looks like a giant Frisbee. Taproots are rarely present because oxygen levels decline with soil depth. Over 80% of the “feeder roots” are in the upper 6 – 8 in. of the soil; that’s where the highest level of oxygen is found. The horizontal spread of a tree’s root system is 2.5 – 3.0 times the crown spread with more than 60% of the roots growing outside the dripline. Obviously, cutting the roots at the dripline is a recipe for a tree health disaster.
The Great Cover-Up
Tree moats and so-called “volcano mulch” often go hand-in-hand; perhaps to hide the first offense. Volcano mulch is so-named because of its sculpted resemblance to a stratovolcano; like Mount St. Helens before it blew its top.
Frankly, I fail to understand why in the name of all that is horticulturally holey do we continue to see mulch piled around tree trunks to stratospheric heights? What is the appeal? And, why can’t we stamp out these mulch monstrosities despite years of educational efforts?
Volcano mulch does not kill trees outright; if it did, people wouldn’t do it. Instead, it produces many of the same subtle, long-term, ill-effects I’ve described with soil mounded over a tree’s root system during tree moat excavation.
Although bark mulch is at first light and airy, it will ultimately compact as it degrades to interfere with oxygen reaching tree root cells. Trees respond by growing roots into the mulch; however, the roots can become exposed as the mulch further degrades.
As with the soil mounded onto the root system during tree moat excavation, volcano mulch can also cause roots to turn back towards the main stem to encircle the tree trunk. In fact, it is common to see stem-girdling roots associated with volcano mulch, particularly with maples.
As the mulch decomposes and dries out, it will eventually start to repel water; it becomes hydrophobic. You can observe hydrophobicity of dry organic matter when you try to moisten a bag of dry peat moss. Of course, water repellency ultimately causes infiltrating roots to dehydrate.
The deleterious nature of tree moats and volcano mulch are not immediately apparent. While moisture starvation and vascular strangulation can ultimately kill a tree, along the way they produce tree stress. This can induce trees to drop their defenses against infestations by opportunistic insect pests such as native borers or infections by plant pathogens. Of course, the pests and diseases get blamed if a tree succumbs, not the bizarre horticultural practices that set the tree’s demise into motion in the first place.
Authors Joe Boggs
Published on May 2, 2019
Calico scale (Eulecanium cerasorum) females spend the winter as small, crusty late instar nymphs (crawlers) stuck on plant stems. Although clearly evident, they may be missed by the uninitiated.
Everything changes in the spring when the females “puff-up” as they mature and start pumping out impressive quantities of honeydew. This is currently happening in southwest Ohio much to the consternation of anyone who parks their cars beneath infested trees.
Calico scale is a “soft scale” meaning that female scales are protected by a soft helmet-shaped shell. This is a relatively large soft scale with mature female shells measuring about 1/4″ in diameter. The scale’s common name comes from the starkly contrasting calico pattern of black-and-white markings on the shells of live females found on the stems in late spring to early summer.
Scale Poo Origins
As with all soft scales, calico scale adults and nymphs (crawlers) feed by inserting their piercing-sucking mouthparts into phloem vessels. They must extract a large amount of sugary sap flowing through the vessels in order to acquire the small amount of amino acids dissolved in the sap that are used to build proteins.
They discharge excess sap from their anus in the form of a sticky, sugary, clear liquid called “honeydew;” a polite name for liquid scale poo. The honeydew drips onto the leaves and stems of infested trees as well as understory plants, sidewalks, lawn furniture, and stationary entomologists. I visited some infested trees yesterday to check the development of the scale and my hat, shirt, glasses, and camera quickly became speckled with the sticky scale poo goo.
Black sooty molds quickly colonize the honeydew imparting a black veneer to stationary objects. Despite its unsightly appearance, the sooty molds cause no direct harm to plants other than possibly interfering with photosynthesis.
What’s Up Next?
Currently, calico scale females in southwest Ohio are only about 1/2 – 3/4ths their mature size. They will continue to spew honeydew as they mature towards egg production. The females can produce more than 1,000 eggs, so populations can build rapidly.
Calico scale females die after producing their eggs and quickly turn reddish-brown and appear deflated. The dead females will remain evident throughout the remainder of the season and may give the false impression that control efforts such as insecticide applications were effective. In fact, I’ve received pictures over the years of calico scale females that died of natural causes but were being used as proof that an insecticide application was effective.
The 1st instar crawlers that hatch from the eggs migrate to the underside of leaves where they attach themselves to veins. They suck fluid from phloem vesicles and drip honeydew; it’s a family business.
A Host of Problems
Calico scale has a wide host range. In fact, few landscape trees in Ohio other than conifers are beyond the reach of this Asian native. Here is a partial A-to-Z list of possible hosts: buckeye, crabapple, dogwood, elm, hackberry, hawthorn, honeylocust, magnolia, maple, oak, pear, redbud, serviceberry, sweetgum, tuliptree, poplar, witchhazel, yellowwood, and Zelkova.
Fortunately, as with most soft scales, calico scale is seldom a direct killer of established landscape trees. But heavily infested trees may suffer branch dieback and the accumulated stress caused by substantial sap loss coupled with other stress-producing conditions may kill trees. So, the best first step in scale management is to resolve other issues that may affect overall tree health. I’ve frequently observed large, heavily infested honeylocusts that are planted in good sites showing no obvious symptoms. Of course, I don’t park my car beneath them.
Out of Control
Unfortunately, this is one of the most difficult to control scale insects that you may encounter in Ohio landscapes. I predict this Alert will generate a number of e-mails sent to me about the “sure-fired” efficacy of a wide range of insecticides. However, for every glowing testimonial about a particular product, I will receive an equal number of e-mails declaring the product doesn’t work. I do not believe this reflects errors in observations; it reflects inconsistencies in achieving satisfactory outcomes even with the same products.
The high variability in insecticide efficacy has even been reflected in the results of trials conducted by university researchers. Systemic neonicotinoid insecticides that are effective against other soft scales have produced highly variable results against calico scale. Dinotefuran (e.g. Safari) produced satisfactory results in some university efficacy trials while delivering no control in others such as an OSU trial I was involved with in 2014. We targeted crawlers attached to the undersides of leaflets in July and failed to achieve acceptable control with dinotefuran as well as an insect growth regulator. Only Onyx (bifenthrin) provided good results; however, I’ve heard mixed outcomes from arborists using this approach.
Cliff Sadof (Purdue Entomology) has been involved with numerous calico scale insecticide efficacy trials over the years and I contacted him a few months ago to seek his perspectives on the varying results. Based on observations he made with some dinotefuran trials, he posited that there may be a connection between achieving good control and providing adequate and consistent irrigation after the application. I believe it’s something applicators should strongly consider.
Regardless, there are few effective management tactics that can be applied at this time of the year to suppress a calico scale infestation. Unlike many other soft scales, calico scale is not controlled with horticultural oil applications. Dormant oil applications are also ineffective.
However, in a pesticide applicator training presentation, Dan Potter (University of Kentucky, Entomology) reported that a number of years ago, a UK entomologist armed student volunteers with bathroom scrub brushes to physically remove calico females before they produced eggs. The method worked well and could be considered for small trees. Sometimes we forget the value and efficacy of simple, direct methods to control insect pests.
Authors Jim Chatfield
Published on May 2, 2019
On Tuesday, despite the misting rain, I felt it would be horticultural malpractice to not get outside for a walk, camera in hand, at OSU’s Secrest Arboretum in Wooster. The plants outside stopped sleeping/the amphibians still are peeping/buds leaves flowers and fruits are here/It’s the greenest time of year. What did I see?
First up are Deciduous Conifers. Needles and cones – evergreen, right? Not always. We have four genera of conifers that lose their needles in the fall in Ohio: dawnredwood (Metasequoia), baldcypress (Taxodium), larch (Larix), and goldenlarch (Pseudolarix). Check out the compound names of dawnredwood, baldcypress, and goldenlarch, denoting that these trees are not true versions of redwoods or cypresses or larch, but different plant types, kind of like pineapple is not a pine or apple. Enough. I feel like a comma queen or at least a grammar grand-duke or a punctuation prince!
More importantly, these trees are fascinating as their new needles emerge for the year. Come see a twisted stem version of the Japanese larch, the cultivar ‘Diana’, showing just a touch of cold injury but with soft green needles and unusual curvy stems. Cold injury? When could it occur – when was our last frost, anyway – March? What a great spring. Goldenlarch and dawnredwood needles are just emerging and are wonderful against the sky.
Next, near the Children’s Garden at Secrest is a Camperdown elm, though the exact relationship to the original contorted sport found at Camperdown House in Dundee, Scotland is obscure, at least to me, though the original Camperdown was apparently grafted onto Ulmus glabra. Like American elm (Ulmus americana), Camperdown elm produces its flowers and fruits in spring, unlike the lovely lacebark elm (Ulmus parvifolia) with its late summer flowers and subsequent fruits.
Years ago, in the old Shade Tree Plot at Secrest, a heavy late fall wet snow got caught up on still present lacebark elm fruits and the weight resulted in major branch breakage. As for the lovely low-growing “Camperdown-ish” elm at Secrest, they are in heavy fruit now, and are a light, fresh green delight.
Culinary note: I should probably serve these wafer-like fruits in a vinaigrette. I did once partake of an elm -fruit salad in China. Vinegary; about the same flavor as goldenraintree shoots or willow leaves in vinaigrette at a restaurant at the Great Wall. Speaking of fine dining, when I googled Camperdown elm, I noticed there is an Camperdown Elm restaurant in Park Slope, Brooklyn. Since it is a few miles from my daughter’s apartment I shall have to try it out soon. Hmm, let’s check the menu: “Crackers made with squid ink topped with a paté of mackerel.” I’ll bet it goes great with marinated elm fruits!
Crabapples. Those who know my crabarian ways now will expect a pome tome, but I shall resist except to say that a number of crabapples have already started to bloom at Secrest, but many are in that most perfect malusarian moment: when buds and their inner blossoms are of different color combination. There is a 2-3 week span from the earliest to the latest crabapples for bloom, so there is no one time for all, but I decree that this weekend and early next week will be the Crablandia Peak. Come scale Secrest.
New Leaves. Do not. Do not miss this. There is nothing more wondrous in nature and so easy to miss than the emergence of new leaves and their accoutrements this time of year. Nurserymen and landscapers and garden center professionals and arborists are so busy they have little time to pause for a few moments. The rest of us may not pause in the yards if there is a sprinkle or two. End-of-school activities deflect us. But just do it. Take some time each day to focus your attention and even to make your own weather and note how lovely reawakening life arrives.
The tiny miniature leaves of oaks along with their dangling flowers. Hostas swirling and rising from their winter slumber. Ladys-mantle with it hydrophobic leaves pooling crystalline water droplets. The many versions of maples unfurling and often paired with their often not noticed flowers. The otherworldly sticky buds bursting and unraveling into leaves of horsechestnuts and their hybrids. Check all of this out at Secrest or at a park or landscape or streetscape or backyard or balcony near you.
Rhododendrons. A few azaleas are out at Secrest, but the glory of the genus Rhododendron is yet to come. Nevertheless, I share here one rhododendron picture. My office on the second floor of the Old Administration Building at the OARDC in Wooster is the one on the second floor with the air conditioner attached. Visit sometime and I will try to take you to the tower of the building, or at least to the tunnels below. If. If the rhododendron has not swallowed me up by then: I advise you come before my retirement in the year 2525…If man is still alive…If woman can survive…
Flowers. With buds like pearls, as in pearlbush (Exochorda). Butter yellow flowers on a cucumbertree hybrid (magnolia). A panicle of flower buds on red buckeye. Sassafras flowers; here for only a short time. Soft pink Carolina silverbell flowers each subtended by a chocolate-colored calyx (the floral envelope made up of sepals behind the petals). Common lilac flowers bursting from buds right on its growing degree-daytime schedule of 234. River birch catkins (the male flowers) filled with pollen. Headily sweet aromas of fragrant viburnum blooms.
Buckeyes. The flowering period for Ohio buckeyes, horsechestnuts, and buckeye-horsechestnut hybrids is past for Secrest, but red buckeyes and later yet, bottlebrush buckeyes are yet to flower. Nevertheless, the flower buds of red buckeye and the wonderfully creased leaves just emerging on both of these buckeyes are outstanding now.
A Final Disease (or Three). Cedar rusts. Joe Boggs did a more complete job with wondrous images in a recent bygl-alert (Rusts Arise :node 1244), but there can never be enough pathological parsings. Cedar rust diseases are a fascinating example of plant host range. To complete its life cycle and the plant disease cycle, the fungus must go through an elaborate ballet of spore stages while spreading from junipers (Eastern red cedars) to a rosaceous host, such as apple/crabapple, hawthorn, quince and serviceberry, among other members of the rose family. Right now the dance consists of microscopic spores emerging enmasse from spectacular abnormal growths (galls) on the juniper, blowing in the wind, randomly answering the call of a windward rose family host.
Lacking Marvelesque microscope-eyes, we will not see their arrival on the hawthorn et al, their infection thereupon, or their conjugal visits with each other, but will see them again when a new spore mass emerges on the underside of the leaves and on fruits. For now, though, what we see is the orange spore horns emerging on the junipers. Risking a pie in the face from an apple orchardist, I will say, the orange telial horns emerging from the galls on junipers now is as pretty as a (admittedly) garish flower.
My final, and I have heard for years by professional landscapers and home gardeners alike – controversial – flower pick right now is –sweetgum, Liquidambar styraciflua. Oh, the wonders you’ll see, if only you look. Right there along with the much-maligned mace-like gumballiferous fruits from the past season, are the cool tiny gumball female flowers and the male cone-like pollen-bearing flowers nearby. Exquisite, even if you hate later cleaning up the eventually brownish, spiky, fruits unpleasant for landscaper equipment and barefoot gardener feet.
All this – and much more on a short Spring Sojourn Walk at Secrest.
Authors Thomas deHaas
Published on May 2, 2019
Students at Perry High School in the group, Students Against Destructive Decisions (SADD) installed the Good Decision Garden at the entrance of the school.
Students walk past the planting as they arrive and leave school each day, enjoying the flowering display all spring.
With donations from local nurseries, the students installed materials last fall with the goal of continuous color from March through July, under the guidance and direction of OSU Extension-Lake County. Students are excited to see what will bloom next.
Plant Suggestions for the Good Decisions Garden (Flowers April-June)
- Dicentra – Bleeding Heart
- Creeping Phlox
- Allium (purple sensation)
- Lilac ‘Miss Kim’
- Peony pink dawn
Not only is the garden making a difference in student lives, it made a difference in those who installed the planting.
Authors Joe Boggs
Published on May 1, 2019
It may be wise to be skeptical when hearing news that a native bio-ally is coming to our rescue in dealing with a non-native insect pest. Disappointments abound. Non-native juggernauts may steamroll because our native predators, parasitoids, and pathogens (the 3-Ps) just don’t recognize them as a food source.
Of course, sometimes they eventually do. Good examples are Japanese beetles (Popillia japonica) and gypsy moth (Lymantria dispar). In many parts of the U.S., these non-natives now behave much like natives with periodical outbreaks eventually crashing because of the 3-Ps as well as environmental challenges.
That’s why cautious optimism may be justified with recent news about a discovery near Reading, PA, of two native fungal insect pathogens hammering spotted lanternfly (SLF) (Lycorma delicatula). The two unrelated native fungi were Batkoa major and Beauveria bassiana and they produced two different diseases that significantly reduced the SLF population.
The research was published on April 22, 2019, in PNAS: Proceedings of the National Academy of Sciences of the U.S.A. Quoting from the research paper: “This coepizootic occurred when females were gravid but before most oviposition, and due to the massive L. delicatula mortality, only 12 egg masses were found.”
You can read the entire paper by clicking this hotlink: https://www.pnas.org/content/early/2019/04/24/1903579116
You can also read a nice summary with quotes and informative perspectives from two of the paper’s authors, Eric Clifton and Ann Hajek, by clicking this hotlink:
Authors Joe Boggs
Published on May 1, 2019
Our native Pine Needle Scale (Chionaspis pinifoliae) was once a common and troubling “key pest” back when Mugo pines (Pinus mugo) rivaled yews (Taxus spp.) and junipers (Juniperus spp.) as one of the most common landscape plants in Ohio and Scotch pine (Pinus sylvestris) was THE Christmas tree grown in our plantations. However, that’s changed over the years.
As mugos have become less common in our landscapes and Scotch pines largely replaced by other conifers in our Christmas tree plantations, so has the occurrence of pine needle scale become a rare thing in both locations. In fact, I’m now down to only one landscape in southwest Ohio where I can monitor a scale-infested mugo. All of the other locations have removed their mugo “scale trees.”
However, that doesn’t mean we should turn our backs on pine needle scale; plant pests have a way of sneaking up on us when we do. Beyond Scotch and mugo pines, this native scale may be found on a wide range of conifers including eastern white pine (P. strobus); Douglas-fir (Pseudotsuga menziensii); hemlocks (Tsuga spp.); spruces (Picea spp.); junipers (Juniperus spp.); cedars (Cedrus spp.); and firs (Abies spp.).
Pine needles scale is a type of “armored scale” (family Diaspididae) meaning much of its life-cycle is spent under a hard protective covering. Armored scales insert their long piercing-sucking mouthparts into plant tissue to slurp-up the contents of ruptured plant cells.
This is unlike so-called “soft scales” (family Coccidae) that feed by inserting their piercing-sucking mouthparts into phloem vessels to extract amino acids that are dissolved in the sugary plant sap flowing through the vessels. They discharge excess sap from their anus in the form of a sticky, sugary, clear liquid called “honeydew;” a polite name for scale diarrhea. Of course, the honeydew is commonly colonized by unsightly black sooty molds. Armored scales do not produce honeydew, so infested trees do not become blackened with sooty mold.
As with all armored scales, pine needles scale 1st instar nymphs are the only mobile stage in this sucking insect’s life-cycle; thus, the name “crawler.” It is also the stage that is most susceptible to insecticide applications. The tiny, dot-like pine needle scale crawlers are dark pinkish-red to rusty-red. Once the crawlers settle to feed, they turn tannish brown. A 10x hand lens is helpful with detecting and monitoring the scale crawlers.
It’s a Generational Thing
Overwintered pine needle scale eggs are hatching right now in southern Ohio. This scale has two generations per season with populations expanding considerably with the second generation; the so-called “summer generation.” This means reducing the number of first-generation crawlers (the “spring generation”) will have a significant impact on decreasing the overall infestation by preventing the population contribution by the second generation.
Also, first generation eggs typically hatch over a relatively short period of time meaning that if management includes the use of a topical insecticide, a single application may be sufficient. Second generation eggs hatch over a prolonged period of time often requiring multiple applications depending on the residual activity of the insecticide product.
Spring generation crawlers hatch from overwintered eggs when the accumulated Growing Degree Days (GDDs) reach 305. Although common lilac (Syringa vulgaris) reaches full bloom at around 315 GDDs, I’ve found this to be a pretty good indicator plant for the appearance of 1st generation crawlers.
Research has shown that a number of bio-allies such as lady beetles and other scale predators as well as parasitoids play an important role in holding scale populations below damaging thresholds. Insecticidal soaps and horticultural oils are effective against scale crawlers and will spare the beneficial insects. The downside is that both will only kill on contact meaning that thorough coverage is required since there is no residual activity. This also means pine needle scale crawlers should be closely monitored in case an extended egg hatch occurs and new crawlers escape the first application
Many standard insecticides labeled to control armored scales on the infested conifer species are also effective against scale crawlers. However, the downside is that these products may also kill bio-allies.
The systemic neonicotinoid, dinotefuran (e.g. Safari, Transtect, Zylam, etc.), has proven effective against armored scales and will have a limited impact on beneficials. However, applications must be made prior to egg hatch to allow time for the active ingredient to reach plant tissue in concentrations sufficient to kill the crawlers. The neonicotinoid, imidacloprid (e.g. Merit), is not effective against armored scales. In fact, some research studies have shown applications of this systemic insecticide actually contributes to scale outbreaks.
Authors Thomas deHaas
Published on May 1, 2019
Lake County is one of 51 counties in Ohio that fall under the European Gypsy Moth Quarantine.
Currently 51 counties in Ohio are regulated under the Gypsy Moth quarantine. Gypsy Moth regulated articles include, but are not limited to: trees and woody shrubs, including cut Christmas trees; logs, pulpwood, slab-wood, firewood, and wood-bark chips outdoor household articles, including: tables, doghouses, planters, garden equipment, playhouses recreational vehicles other products or articles, or means of conveyance that may carry a life stage of the Gypsy Moth
Producers who ship nursery stock out of regulated areas to non-regulated areas must have their stock inspected and a certificate, which attests to the fact that their product is free of gypsy moth, must accompany each load. Producers, who make repeated shipments, are urged to take steps necessary to qualify for a “Gypsy Moth Compliance Agreement” and master certificate; otherwise, they will face delays in obtaining certificates.
Compliance Agreements are written agreements between an entity engaged in growing, selling, processing, or moving regulated articles from a regulated area and the Ohio Department of Agriculture, setting forth specified conditions to prevent the spread of the gypsy moth. This agreement is needed by anyone moving regulated articles out of a regulated area to a non-regulated area and anyone in a non-regulated area receiving regulated articles from a regulated area.
One main requirement for the compliance agreement is that nurseries must apply a USDA-approved insecticide to the entire growing area in mid to late May.
For more information, contact the Plant Pest Control Section at 614-728-6400 or your local nursery inspector.
Assume that helicopters will be spraying in late May 2019. Typically, the product sprayed is a growth regulator that prohibits the European Gypsy Moth to complete its life cycle into an adult moth that is able to reproduce. The product used has a low toxicity to people and pets. People are encourage to stay indoors while active spraying is occurring. If you have any other questions, please feel free to contact the Ohio State University Office of Extension – Lake County, Ohio.
Thomas deHaas – Agriculture Natural Resource Educator
Authors Jim Chatfield
Published on April 30, 2019
One of the intemperate dilemmas for plants in the off-season is stem damage known as “frost cracks”. It is not completely understood, but one working theory is that with rapid temperature fluctuations, water in stem cells moves out of the cells during warm weather, freezes, and damages the shrunken stem cells. Longitudinal cracks in the trunks then develop.
Precisely what conditions result in frost cracks on a particular plant and did we see a lot of this resulting from the winter of 2018-2019? This is difficult to answer since sometimes damage to the stem is not apparent until later in the growing season, but we have not heard of widespread damage this spring. Did rapid temperature plunges occur on certain days this winter or early spring – hard to say depending upon the particular plant microclimate. However, herein is one seemingly clear-cut case of crabapple crime.
One clue is that the northeast Ohio ‘Sentinel’ crabapple in question is thin- and smooth-barked when young and crabapples and apples (the genus Malus) are one of the trees, along with maple, beech, lindens and others that are particularly susceptible to frost cracks when young. Second, damage from frost crack is typically worst on the southern or southwest exposures of the stems, and that was the case for the each of the trees in this incident.
What is the prognosis for these trees? Damage may cause problems, primarily by exposing the stems to ingress by pests and pathogens. However, frost cracks are not necessarily harbingers of doom. Otherwise healthy trees often develop good callus at the edge of the cracks and proceed into their teens and on to older age. Time will tell. Clean up the crispy bark along the edges and employ typical plant health maintenance.
What can be done to prevent frost cracks in the first place? The most typical approach is the use of tree guards or white latex paints on the trunks of young trees of susceptible species. The idea for this is to protect the tree from overheating during the heat of a winter or early spring day in which rapid temperature plunges then occur. This is why orchardists paint the trunks of fruit trees in order to reflect the heat of the sun during the warm period of the day.
These measure are less commonly seen with crabapples then apples, but it is a good idea. “Sentinel” means “to guard, to stand and keep watch.” Apparently, this ‘Sentinel’ crabapple, this member of the “Night Watch”. failed in its vigil at this place in this time.
Authors Thomas deHaas
Published on April 29, 2019
It all happened at once this year. Forsythias, Magnolias, Dogwoods, Serviceberry are all blooming near the same time. In addition, Crabapples, Quince, Cherry, Pieris, Phlox, Hyacinth, and Tulips are all in flower. Although invasive, even Flowering Pears are pretty as well.
PJM Rhododendrons are striking.
It was a wonderful spring for Magnolias with no hard frost through the flowering season.
As you admire the beauty of all in flower, make a note of what you would like to add or replace in your landscape.
Enjoy the “Most Wonderful Time of the Year”!