for Arborists, Landscape Managers & Nursery Managers

Commercial Horticulture June 30, 2017Coordinator Weekly IPM Report: Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed Landscapes, sgill@umd.edu. 301-596-9413 (office) or 410-868-9400 (cell)

Regular Contributors: Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury (Extension Specialists) and Nancy Harding, Faculty Research AssistantDisease Information: Karen Rane (Plant Pathologist) and David Clement (Extension Specialist)Weed of the Week: Chuck Schuster (Extension Educator, Montgomery County)Cultural Information: Ginny Rosenkranz (Extension Educator, Wicomico/Worcester/Somerset Counties)Fertility Management: Andrew Ristvey (Extension Specialist, Wye Research & Education Center)Design, Layout and Editing: Suzanne Klick (Technician, CMREC)

In This Issue...

If you work for a commercial horticultural business in the area, you can report insect, disease, weed or cultural

plant problems found in the landscape or nursery to

sklick@umd.edu

TPM/IPM Weekly Report

- Fall webworms- Scale update- Flower longhorn beetles- Japanese beetles- Twobanded Japanese weevil- Hydrangea leaf spot- Rose midge- Dobsonfly- Lace bugs- Baldcypress twig gall midge- Bagworms- Mites on hornbeams- Renovating in-ground nursery soils with biosolids

Beneficial of the WeekWeed of the WeekPlant of the WeekPhenologyDegree DaysAnnouncements

Pest Predictive Calendar

IPMnetIntegrated Pest Management for

Commercial Horticulture

extension.umd.edu/ipm

Hyperactivity of Fall Webworm By: Stanton Gill

We are receiving dozens of e-mails of pictures of fall webworm feeding heavily in June. The fall webworm, Hyphantria cunea, is a widely distributed native pest of shade trees and shrubs and appears in most typical years (this is not a typical year) from late summer through early fall. It feeds on almost 90 species of deciduous trees commonly attacking hickory, walnut, birch, cherry, and crabapple.

We have seen this caterpillar active in other years in June and throughout the summer. For some reason it started activity in early June and has continued through the month with a lot of defoliation in the landscape. Fortunately, we have several good safe materials to control this pest including spinosad (Conserve), Acelepryn, and Mainspring (from Syngenta Company). Bt works well if the caterpillars are caught in the early instar stage.

Fall webworm caterpillars are feeding within webbing on this tupelo in OlneyPhoto: Steve Castrogiovanni, Mead Tree and Turf

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Japanese Maple Scale, Cottony Camellia/Taxus Scale, and Euonymus Scale ActivityBy: Stanton Gill

Crawlers are still out for Japanese maple scale this week and we are finding a number of settled 1st instar stages on plants. The cottony Camellia/Taxus scale crawler period is just ending, but we are finding large numbers of settled 1st instar stages. It is a good time to apply either Talus or Distance insect growth regulators. Last week, Brian Kunkel (University of Delaware Extension) and I made the treatments at our trial blocks. We are looking at soil drenches of Altus compared to foliar applications. We also have foliar Talus applications in the trial for both of the aforementioned scale insects.

Mark Schlossberg, ProLawn Plus, Inc., found euonymus scale adult males and females on euonymus this week. First generation crawler activity is finishing up. Look for second generation crawlers in late July into August. A mixture of 1% horticultural oil and pyriproxyfen (Distance) or buprofezin (Talus) can be used when crawlers are active.

Fall webworm caterpillars feed as a group within the webbing

You cannot miss this caterpillar - young larvae are pale yellow with two rows of black marks along their bodies. When fully grown, they are covered with whitish hairs that originate from black and orange warts. Larvae vary as to their coloring and markings, but are usually greenish with a broad, dusky stripe along the back with a yellow stripe along the side.

Though they are active in June they may continue to emerge in small numbers during most of the summer. Females usually deposit their egg masses on the undersurface of the leaves. Larvae hatch in approximately 7 days. They immediately begin to spin a small silken web over the foliage on which they feed. Expect to see activity through the summer into the early fall.

Both adult males (white) and females (dark brown and oyster shell shaped) are presentPhoto: Mark Schlossberg, ProLawn Plus, Inc

Flower Longhorn BeetlesSteve Castrogiovanni, Mead Tree and Turf, found flower longhorn beetles (Typocerus sp.), swarmping all over a hydrangea in Woodbine this week. He noted that “from a distance, I thought it was a beehive”. Adults feed on flowers; larval food depends on the species.

Flower longhorn beetles were swarming around hydrangea flowers this weekPhoto: Steve Castrogiovanni, Mead Tree and Turf

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Japanese Beetles Activity By: Stanton Gill

The years 2015 and 2016 were BIG Japanese beetle year. The 2017 summer season will likely be another big year for adult activity. Thanks to each of you who have sent in early activity of the beetles. You can stop now since we have established they are out and active. The Japanese beetle is probably the most devastating pest of urban landscape plants in the eastern United States. Japanese beetles were first found in this country in 1916, after being accidentally introduced into New Jersey. Until that time, this insect was known to occur only in Japan where it is not a major pest.

Why so many this year?Mid-summer rainfall and adequate soil moisture are needed to keep eggs and newly-hatched grubs from drying out. Females are attracted to moist, grassy areas to lay their eggs. In 2016, we had rain up until the end of July which made conditions ideal for egg survival and hatch. The drought period occurred from August through September which might have helped knock down a few larvae in the soil. We will see what develops as the summer progresses.

Brian Kunkel, University of Delaware Extension, Suzanne Klick, Chuck Schuster, and I conducted two years of testing of Acelepyrn, Mainspring, and Btg for control of the adults. All three materials work well. So, you have these relatively new products along with a host of older chemistry available for control.

Twobanded Japanese WeevilBy: Stanton Gill

I received in an interesting picture of an insect I have not seen in awhile. It was of a twobanded Japanese weevil, Pseudocneorhinus bifasciatus (Roelofs), that was found on a Knockout rose planting in Washington D.C. this week. Before 2001 I used to get in samples of this weevil on a regular basis. The last sample I had was in 2008. This weevil used to be a big deal in nurseries and landscapes when azaleas were the “hot” plant in commercial landscapes. Azaleas fell out of favor and were replaced with Knockout roses.

The twobanded Japanese weevil is native to China, Japan, Korea, Mongolia, and eastern Siberia. This weevil was first collected in the United States in 1914 near Philadelphia, was most likely introduced with infested nursery stock from Japan. It is often moved into landscape in the larval stage which feed on the roots of plants. Adult weevils have fused elytra (hardened forewings) and do not have flight wings so they cannot fly. Once it is established in the landscape it tends to stay around since the weevil does not fly and goes only as far as it can walk or be carried.

Eggs are cream-colored and laid within egg pods of one to nine eggs on leaf margins. After hatching, larvae drop the ground to burrow into the soil to feed on the roots. Adults can defoliate plants and larvae damage roots.

Japanese beetles are now feeding on a wide variety of plants in landscapes throughout the area

This twobanded Japanese weevil was recently found on Knockout roses

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Fig. 1. Oakleaf hydrangea with leaf spots on lower leavesPhoto: Karen Rane, UME

Hydrangea Leaf SpotBy: Karen Rane

Oakleaf hydrangeas (Hydrangea quercifolia) are now developing reddish-brown or purple leaf spots – symptoms of bacterial leaf spot caused by Xanthomonas campestris. This disease commonly occurs during warm, wet weather in late spring and early summer. While other hydrangea species, such as H. arborescens and H. macrophylla, are also susceptible, the disease seems to be most severe on oakleaf hydrangeas. Symptoms are usually first observed on lower leaves, and the pathogen moves upward in the plant canopy through rainsplash or overhead irrigation. In the landscape, removing lower leaves as soon as leaf spots are first observed can help slow disease spread. Overhead irrigation of hydrangeas should be avoided, or timed to keep leaf wetness periods to a minimum. In nurseries, increased plant spacing can help increase air circulation, keeping foliage as dry as possible reduce disease.

Fig. 2. Bacterial leaf spot on oakleaf hydrangea caused by Xanthomonas campestrisPhoto: Karen Rane, UME

When I searched the literature it was mentioned that they tend to lay many more eggs when feeding on multiflora rose. Since this recent find was on Knockout roses it may be that the weevils will do very well on this crop. Here is the interesting part: like the black vine weevil, twobanded Japanese weevils reproduce parthenogenetically, and males are generally not encountered in the United States although they are known to occur in China. So, you just need one female to bring a problem into a landscape or nursery setting. Other hosts recorded by Marrone and Zepp (1979) include azalea (Rhododendron), privet (Ligustrum), Forsythia, Abelia, Viburnum, Acer, Morus, Populus, Sedum, Lythrum, Campsis, Thunbergia, and Coleus. Twobanded Japanese weevils are likely to be found in cherry laurel (Prunus laurocerasus), Pyracantha, Euonymus, barberry (Barberis) (Day 2003). This part of fondness for cherry laurel has me concerned. To check for the weevils, tap or shake the infested plant. A white sheet of cloth or paper could be laid out under the shrub to catch them as they drop. If you run into this pest in the nursery or landscape contact me at Sgill@umd.edu.

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Rose MidgeJessica Frakes, SavATree, found some rose midge egg laying sites on roses in D.C. this week. Look for larvae in newly formed buds. If present, buds do not develop, turn brown, wither and fall off thus preventing new flowers. Control: Early timing is very important for getting control. Removing mulch around rose shrubs in late winter removes some of the pupating rose midges. Putting fresh mulch on in early spring buries deeper any remaining midges. Physical removal can also help with control. Monitor weekly for infested shoots throughout the growing season and prune off infested shoots when possible. There are up to 35 larvae in one shoot. Black shoots are an indication that the larvae are gone. Applications of spinosad or cyfluthrin applied every 10 days will help to control the insect.

If you seed damged tips on roses, look closely for rose midges

Dobsonfly

Dave Keane, Howard County Recreation and Parks, found this dobsonfly in Columbia on June 28. Your customers may see this large insect with elongated mouthparts resting on plant material in the landscape. The dobsonfly is one of the largest aquatic insects you will find in Maryland. Adults measure two to four inches from the front of the head to the wing tips. They are soft-bodied and brownish-gray with the wings held rooflike over the body. The wings have a large number of veins (lines) and are often mottled. The antennae are long and threadlike. Males have long, curved, sickle-shaped mandibles (jaws) approximately 1 inch in length. The females have short inconspicuous jaws.

Dobsonflies are active at night and are attracted to lights. They have an awkward fluttery flight but still travel considerable distances and are occasionally found some distance from a body of water. Adults live for a brief period and do not feed. Handling dobsonflies can be somewhat risky. It is the female with the short, inconspicuous mandibles that can inflict the more painful bite if handled carelessly. No control treatments are necessary. It is just one of those interesting insects your customers may find in their yard in June.

Dobsonflies are large insects that are sometimes seen at this time of yearPhoto: Dave Keane, Howard County Recreation and Parks

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Lace BugsWe are getting reports of lace bug infestations this week. Marie Rojas, IPM Scout, is reporting that they are just starting to feed on leaves of Amelanchier ‘Autumn Brilliance’ in Gaithersburg. Nick Hoxter, SavATree, is reporting, “Very large population of lace bugs adults and nymphs found in Herdon, VA. Most I have ever seen. You could shake the foliage on to your hand and it would covered! Foliage was mostly white.” Look for yellow stippling of new growth. Look on the underside of foliage for nymphs, adults, and black fecal spots. Damage on new growth indicates eggs have hatched and the new generation has started to feed. For control, get good coverage with horticultural oil on the underside of foliage to reduce populations. Many products are labeled for lace bugs.

Multiple stages of azalea lace bug are present on this foliage; also note the black fecal spotsPhoto: Nick Hoxter, SavATree

Baldcypress Twig GallMarie Rojas, IPM Scout, is finding the baldcypress twig gall midge on trees in Gaithersburg. Orange-yellow midge fly larvae (maggots) develop and overwinter within the galls. There are two generations per year.Control: Pruning can be done to reduce the number of galls present. Remove and destroy dropped galls in fall or spring to reduce the numbers of the next generation of adults that will emerge next spring. There are several species of wasps that parasitize gall-forming insects and help reduce the number of galls formed. Pesticides are usually not recommended. Timing of chemical controls is critical because applications need to be made before galls begin to form. This gall on baldcypress is caused by a fly midge

BagwormsMarie Rojas, IPM Scout, is reporting that she is finding bagworms in Gaithersburg that are still very small. Reports of egg hatch has varied a bit across the region this year. We actually had reports of hatching caterpillars in Virginia and Pennsylvania before any locations in Maryland.Control: It is best to control bagworms when the are still small. Bt (Dipel, Caterpillar Attack), Spinosad (Conserve) or Acelepyrn will all give good control of young larvae.

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Renovating In-ground Nursery Soils With BiosolidsBy: Andrew Ristvey

Yesterday, at the well-attended MNLGA Field Day at Ruppert Nurseries, I gave a short presentation on the use of biosolids as an organic amendment for soil renovation. This project started last fall when Nick Graves, Nursery Manager at Ruppert, contacted me about using the biosolids. Any field renovation using high quality organics is a good idea. Organics add carbon into the soil, which starts a cascade of good biological, chemical and physical changes that improve the health of the soil and in turn, improve the health of the plants. Certainly, this is a good thing when plant growth is what a business relies upon for its wellbeing and profit.

My first concern was phosphorus. Organics, whether composted or not, are typically considered a form of fertilizer, based Maryland’s nutrient management regulations. They typically contain nutrients, especially nitrogen and phosphorus (P). When adding any nutrient to soils, especially P, there are several factors which play into determining the application rates.

First is crop nutrient removal. Agronomic research has nailed down removal rates for grain crops, but little if any of that information exists for shade trees and other ornamental crops. Steve Black, owner and operator of Raemelton Farm has considered figuring this out for a variety of his tree species, and I believe he has the aptitude to do it.

Second is soil chemistry. Several factors need to be taken into account like cation exchange capacity (CEC), soil pH and the present soil P content. Cation exchange capacity holds cations to soil particles. Since P is in the form of an anion, lower soil CEC will create more opportunity for P to be bound by cations like aluminum and iron, making it less available and increasing the need for higher rates of P application. Low pH also increases the need for higher P application rates, since those same cations are more available to bind P, regardless of CEC. Interestingly, high soil CEC acts like a buffer stabilizing pH and preventing soil pH from changing quickly. Organic amendments typically increase soil CEC. And of course, present soil P content will determine the amount applied for a required target.

According to the Ruppert soils analyses, CEC was around 5 meq/100g (low), pH was slightly acidic, and phosphorus levels were very low. I was interested in a target phosphorus level of 45 ppm (Mehlich 3 extraction) which turns out to be around 50 P-FIV, or on the low side of optimum. There are several reasons why I chose this number. First, I did not want to overshoot, and place Ruppert Nurseries in a position of not being able to renovate and amend their soils in the future. Once P is loaded in a soil, it can be very difficult to lower, especially with long-term plants like shade trees. Secondly, as was pointed out during the program by Dr. Francis Gouin, mycorrhizal fungi are suppressed by high soil phosphorus content. Interestingly, Dr. Gouin had been doing a lot of research with biosolids in the past. As always, he was a wealth of information yesterday, adding his knowledge to this program. I was quite honored.

Jessica Frakes found predaceous mites and spider mite damage, but no pest mites on hornbeam trees in D.C.Photo: Jessica Frakes, SavATree

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The goal of raising the phosphorus content to 45 ppm was predicated on Ruppert’s soil chemistry. Published research show a large range of recommendations for phosphorus application rates; between 4.5 and 28 lb P205 per acre to raise levels by 1 part per million (ppm). After consulting with Dr. Gouin last year, Nick and I decided on using 18 lb P2O5 per acre for every 1 ppm P increase. Soil P levels suggested at least 30 ppm increase was needed, based on the averaged soil tests. We needed 540 lb of P2O5 to raise the P content in the soils by 30 ppm and the biosoild was around 7% P2O5 dry. Nick then incorporated about 3.8 tons of biosolid per acre into the soils.

After two months, new soils analyses were taken. The results were mixed. When I averaged all of plot soil tests together the increase in P came out to be 34 ppm. That is where Nick and I wanted to be. However, the range of the P results was quite large. In one strip, P levels went down 3 ppm and in another, they went up 80 ppm. Most increases were between 10 and 20 ppm. The variability may be due to sampling, or more likely to the fact that the biosolid was sticky and lumpy when applied. Heterogeneous application was difficult with the material. However, I believe a large improvement in plant growth will be noticed in time. As the soil consolidates, new populations of microorganisms will grow, organic materials will mix, and greater soil health will be the result. The next 3 years will be very telling.

If you are interested in amending your soils with organics and would like some assistance in determining rates, feel free to contact me at aristvey@umd.edu.

Beneficial of the WeekBy: Paula Shrewsbury, University of Maryland

Cicada killers – are they as dangerous as they look?

About six weeks ago we began to hear the loud “singing” produced by male periodical cicadas, Magicicada spp, trying to entice females to pick them as mates. Those songs stopped about 2 weeks ago as mating ceased, eggs were laid in branches, and adults died. Just these past few days there have been reports of singing in the trees by annual or dog day cicadas, Tibicen spp. Periodical cicadas typically emerge every 13 or 17 years and are active as adults in the spring. Whereas annual cicadas have a 2 to 3 year life cycle and there is cicada emergence each year. Populations of annual cicadas are nowhere near as high as those of periodical cicadas. Annual cicadas begin their emergence about this time and usually remain active into September. I hope you like their music!

Cicadas, especially annual cicadas, are not usually considered pests of plants since their feeding does not cause notable damage and their oviposition into tree branches result in minimal branch tip dieback. So I don’t know if you could truly call this week’s insect, cicada killer wasps, Sphecius speciosus (Sphecidiae), a “beneficial” insect, but it is a parasitoid of cicadas! Although there are some who are not overly fond of insects or the loud singing that goes on for weeks and would appreciate some relief from annual cicadas.

There have been reports of large numbers of cicada killer wasp activity this past week. Not surprisingly the cicada and cicada killer wasp life cycles are closely synchronized. Fortunately, you do not have to worry about being attacked by a cicada killer wasp. First of all only female cicadas are capable of stinging and cicada killers are not aggressive to humans. Cicada killers are solitary wasps (they do

A cicada killer burrow which leads to underground chambers that are supplied with paralyzed but live cicadas for immature cicada killer wasps to feed upon. Photo: Paula Shrewsbury, UMD

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not have colonial nests like honey bees), although you are likely to find several “nests” or galleries in the ground in the same area. Nests are common in areas where soils are dry and somewhat sandy, and turf is thin with bare spots. This is why golfers who spend time near sand traps are familiar with these large wasps. A single female wasp constructs a nest in the ground that contains a main gallery which may be up to a foot deep with several chambers or brood cells running off the main gallery. In each of the chambers the female will rear an individual baby or progeny. The female cicada will mate, and then she searches trees for cicada adults. When she finds a cicada she uses her ovipositor to sting it and inject venom which paralyzes but doesn’t kill the cicada. The cicada killer straddles the cicada grabbing it with her legs, and returns the paralyzed cicada to her nest. Cicadas can be pretty heavy and cicada killers have been seen dragging cicadas or walking up tree trunks or other upright structures carrying a paralyzed cicada. [see video at: https://youtu.be/qM74DdKbEkM]. The idea is that the cicada killer is trying to get enough height to make take off with the cicada possible. She drags the paralyzed cicada into one of the brood chambers where she then lays an egg on the cicada. A very interesting aspect of cicada killer wasp biology is that if the adult female wants to produce female progeny she stocks the chamber with 2 cicadas, whereas she will leave only 1 cicada to produce a male. Female cicada killers are larger than males and therefore require more nutrients to complete development. The egg hatches, the larva feeds from the outside of the live cicada, develops over the next few weeks. It then pupates and remains in this stage until the next spring. When the cicadas are active next July a new generation of adult wasps will emerge and begin the cycle again.

It is not unusual to hear stories of people who have been “chased” or dive-bombed by a cicada killer wasp, or to see large numbers of wasps flying around a given area. These are the male cicadas that are defending their territory and trying to keep other males away from the female he mated with. The males will often perch on a branch of a shrub or small tree and then take flight when other males show up to chase them away. Males are territorial and will defend their territory and fend off other males who might try to mate with “their” female. Humans just happen to be standing in the cicada killer wasp’s territory. I have only known one person who has been stung by a cicada and she was gardening and unknowingly kneeled on a cicada hole. Because of the fear factor associated with these large wasps many people do not want them in their yards. There are a number of chemicals that are available that can be used to “dust” around the holes of the cicada killers. In areas like playgrounds where kids are playing this is a good idea. However, it is the texture, exposure, and drainage of your soil and thickness of your lawn that attracts a new crop of cicada-killers to your lawn each year. If you have the optimal habitat they will come. A more long term management strategy is to alter the habitat to make it less favorable for cicada killer wasps such as improving the density of the turf and soil quality. Keeping the soil moist will discourage females from building nests in these sites. Remember, you do not need to fear the cicada killer wasp!

Cicada killer wasp adult perched on an azalea while guarding his territory from other males. Photo: Paula Shrewsbury, UMD

Weed of the WeekBy: Chuck Schuster, University of Maryland

What is that weed taking on some height in the landscape? It is marestail. Marestail, Conyza canadensis, also known as horseweed or Canada fleabane is an annual weed that is being found in the landscape currently. The seed can germinate in either fall or early spring. The earlier it germinates the earlier in the season it can produce flowers and viable seed. This weed has a short taproot, erect stout stems that are unbranched at the base, with a bushy-branched upper portion. It starts our as a basal rosette. It will grow from 1 to 6 feet in height. The leaves

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Plant of the WeekBy: Ginny Rosenkranz, University of Maryland Extension

Thuja occidentalis ‘Congabe’ also known as Fire Chief™ Globe Arborvitae is a native evergreen shrub that is a sport of Thuja ‘Rheingold’ found by Gabe Cessarini on the Eastern Shore of Maryland. It is an extremely slow growing, compact conifer reaching 2 feet tall and wide after 10 years, and 4 feet tall and wide at maturity. It grows in a nearly perfect globe shape with finely textured foliage that starts out a bright gold in the springtime, then during the summer it is a medium green with bronze gold highlights that matures to a deep red autumn color. It prefers full sun for best coloring and is winter hardly from USDA zone 4-7. Fire Chief™ Globe Arborvitae needs evenly moist, well drained soils with a light layer of mulch. Like all of the Thuja, it will need to have regular, deep watering during the first 3-4 years during the growing season to establish a good root system. Fire Chief™ Globe Arborvitae is less prone to splitting and will need to be protected from winter winds, but is considered air pollution tolerant. Bagworms, scale, spider mites and winter burn can be problems.

are alternate, numerous, and narrow with coarse white bristles about four inches in length and a quarter inch in width. Marestail reproduces by seed and can be found in both turf and ornamental settings. A single marestail plant can produce 200,000 seed usually dispersed between August and October. The seed is smaller than dandelion and can travel up to three-quarters of a mile. Prevention becomes difficult when surrounding areas allow it to go to seed. Marestail will tolerate many different soil conditions, wet, dry, compacted, but it is not shade tolerant.

Fertility management in turf to promote thick turf and proper mowing helps keep this weed under control. Marestail will responds to pH management keeping the soil in the desired range for most cool season turf. It prefers a lower pH. Dicamba, Dimension and 2,4-D are all very effective in turf settings. Be mindful of the issues with herbicides that have volatilization related issues. In landscape beds, post-emergent non selective herbicides (glyphosate) can be effective if used when the plant is small and actively growing. Resistance to glyphosate is being found in many regions in the US including in Maryland. Use the maximum label rate to prevent resistance when possible. Other options for control of this weed in landscape and nursery settings will include pre-emergent use of dichlobenil (casoron), oxyfluorfen and oryzalin (Rout) and Sureguard have shown good control. Applications should be made in early August to prevent this plant from even starting out. One marestail plant can produce up to

200,000 seedPhoto: Chuck Schuster, UME

Thuja occidentalis ‘Congabe’ is an extremely slow growing, compact coniferPhoto: Ginny Rosenkranz, UME

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PLANT PLANT STAGE (Bud with color, First bloom, Full bloom, First leaf)

LOCATION

Asclepias incarnata (swamp milkweed) Bud showing color Ellicott City (June 30)Monarda fistulosa (wild bergamot) First bloom Ellicott City (June 28)Veronicastrum virginicum (culver’s root) Buds showing color Ellicott City (June 30)

Phenology

Degree Days (As of June 28)Annapolis Naval Academy (KNAK) 1632 Baltimore, MD (KBWI) 1489 College Park (KCGS) 1469 Dulles Airport (KIAD) 1534Ellicott City (E247) 1437 Fairfax, VA (D4092) 1673Frederick (KFDK) 1497 Greater Cumberland Reg (KCBE) 1407 Gaithersburg (KGAI) 1421 Martinsburg, WV (C1672) 1367Natl Arboretum.Reagan Natl (KDCA) 1859 Rockville (C2057) 1709 Salisbury/Ocean City (KSBY) 1526 St. Mary’s City (St. Inigoes, MD-KNUI) 1717 Westminster (KDMW) 1585

Important Note: We are now using the Online Phenology and Degree-Day Models site.

Use the following information to calculate GDD for your site: Select your location from the mapModel Category: All models Select Degree-day calculatorThresholds in: Fahrenheit F Lower: 50 Upper: 95Calculation type: simple average/growing dds Start: Jan 1

MDA Pesticide Container Recycling ProgramThe 25th year of the pesticide container recycling program will run from June through September. There are 24 collection days at 6 different sites. See the brochure for dates and locations in 2017. Be sure to properly rinse the pesticide containers before taking them for recycling. The Agricultural Container Recycling Council provides a chipper to grind the plastic containers into flakes, which are then transported to a contractor for recycling. For additional information, or to schedule a chipping date at your site, contact Rob Hofstetter, special programs coordinator, Pesticide Regulation Section, Maryland Department of Agriculture, at 410-841-5710.

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Mark Your Calendars!University of Maryland Turfgrass Research Field Day

Come get pesticide and professional fertilizer applicator recertification credits while seeing cutting edge university research.

Wednesday July 12, 2017 from 12PM to 5PMPaint Branch Turfgrass Research Farm

395 Greenmead DriveCollege Park, MD 20740

Registration is Free to Members of the Following StateOrganizations

REGISTRATION AND SCHEDULE INFO AThttp://psla.umd.edu/news/university-maryland-turfgrass-research-field-day

Get a jumpstart on education credits for the next year and share a great meal with friends and colleagues

8 - MD Pesticide Credits (Categories 3A, 3C, 6, and 10)2 - MD Professional Fertilizer Applicator Credits3 – DE Pesticide Recertification Credits (Category 03) DC Pesticide Recertification (Categories Core, 3A, and 3B)0.4 Sports Turf Managers Association CEUs0.35 Education Points for Golf Course Superintendents Association of America

The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied.

CONTRIBUTORS:

University of Maryland Extension programs are open to all citizens without regard to race, color, gender, disability, religion, age, sexual orientation, marital or parental status, or national origin.

Thank you to the Maryland Arborist Association, the Landscape Contractors Association of MD, D.C. and VA, the Maryland Nursery and Landscape Association, Professional Grounds Management Society, and FALCAN for your

financial support in making these weekly reports possible.

Photos are by Suzanne Klick or Stanton Gill unless stated otherwise.

Stanton GillExtension Specialist

sgill@umd.edu410-868-9400 (cell)

Paula Shrewsbury Extension Specialistpshrewsb@umd.edu

Ginny RosenkranzExtension Educatorrosnkrnz@umd.edu

Chuck SchusterExtension Educator

cfs@umd.edu

Karen Rane Plant Pathologistrane@umd.edu

Andrew RistveyExtension Specialistaristvey@umd.edu

David ClementPlant Pathologist

clement@umd.edu

Nancy HardingFaculty Research

Assistant

Commercial Horticulture Conferences

PGMS Green Industry Field Day July 20, 2017 American University, Washington DC

Green Industry Summer PicnicAugust 19, 2017Location: Just This Side of Paradise Farm, Woodbine, MD

Cut Flower Tour - Eastern ShoreSeptember 12, 2017