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Landscape Message: September 9, 2016

September 9, 2016
Issue: 
20

UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Massachusetts Green Industry professionals in the management of our collective landscape. Detailed reports from scouts and Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. The following issue has been updated to provide timely management information and the latest regional news and environmental data.

The Landscape Message will be updated bi-weekly July through September. The next message will be available on September 22. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list.

Drought Conditions Update: 100% of Massachusetts is currently under official drought status, of that approximately 95% of the Commonwealth is classified as at least 'Moderate Drought', 77% is classified as 'Severe Drought', and nearly 23% is classified as 'Extreme Drought' (All of Essex and Suffolk Counties, approximately half of Middlesex County, the majority of Norfolk County, and large portions of Plymouth and Bristol Counties).  For more information see http://droughtmonitor.unl.edu/Home/StateDroughtMonitor.aspx?MA.

For UMass Extension drought resources for landscapers, see https://ag.umass.edu/news/dry-dry-dry-resources-for-landscapers.  Turf managers with concerns about turf recovery can refer to http://ag.umass.edu/management-updates-aug-25-2016.

NEW! To read individual sections of the message, click on the section headings below to expand the content:


Scouting Information by Region

Environmental Data

The following growing-degree-day (GDD) and precipitation data was collected for an approximately two week period, August 25 through September 7. Soil temperatures and phenological indicators were observed on or about September 7. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2016 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

Region/Location

GDD

Soil Temp
(°F at 4" depth)

Precipitation
(2-Week Gain)

Time/Date of Readings

2-Week Gain

2016 Total

Sun

Shade

Cape Cod

318

2377

78

70

0.85

6:45 PM 9/7

Southeast

265

2229

77

70

0.62

5:30 PM 9/7

North Shore

n/a

2323

66

64

0.26

9:00 AM 9/7

East

289

2575.5

73

69

0.39

4:30 PM 9/7

Metro West

253.5

2353.5

68

65

0.18

6:00 AM 9/7

Central

n/a

n/a

n/a

n/a

n/a

n/a

Pioneer Valley

296

2504

71

69

0.09

10:00 AM 9/7

Berkshires

252

2139

70

68

0.03

11:00 AM 9/7

AVERAGE

231

2357

72

68

0.35

-

Phenology

Phenological indicators are a visual tool for correlating plant development with pest development. The following are indicator plants and the stages of bloom observed for this period:

tr>

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)
PLANT NAME (Botanic/ Common) CAPE S.E. N.S. EAST METRO W. CENT. P.V. BERK.
Heptacodium miconioides (Seven-Son Flower) Begin Begin Begin Begin/Full Begin * Begin *
Clematis paniculata (Sweet Autumn Clematis) Begin/Full Begin Full Begin/Full Begin * Full Begin/Full
Polygonum cuspidatum (Japanese Knotweed) Full Full Full Full Full * Full Full
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: With the exception of a small amount of precipitation from the remains of Tropical Storm Hermine, the Cape has remained dry over the past two weeks. The U.S. Drought Monitor has now moved the Cape into the “Severe Drought” category and landscapes reflect those dry conditions. Daytime temperatures averaged in the upper 70s F, with sunny skies. Perennial Rudbeckia species are providing the bulk of color in landscapes. Hydrangea paniculata cultivars are proving remarkably drought resistant and continue to bloom.

Pests/Problems: Drought stress is the major problem in Cape landscapes. Many trees and shrubs in unirrigated yards are wilting, showing marginal leaf scorch, or defoliating prematurely. While it was hoped that the remnants of Hermine would bring the Cape some soaking rains, only 0.65” was recorded in the rain gauge in Marstons Mills on Labor Day. Previous to that, 0.2” was recorded on September 1st. Many towns on Cape Cod have put water restrictions in place. The long range forecast is for continued warm and dry weather through September. Automatic irrigation systems that are set to short intervals on a daily or alternate day schedules are not supplying adequate amounts of water, especially for any newly planted material, now that we are in the fall planting season. Insect activity remains low. Plant hoppers and spider mites are active. Surprisingly, mosquitoes are still active and West Nile virus has been found in mosquito populations in several towns. Triple E (Eastern Equine Encephalitis) was found in a mosquito in South Yarmouth, a first for the Cape.

Giant tar spot was observed on Norway maple, although not as severely as seen in previous years. Powdery mildew is active on susceptible phlox and beebalm. Black spot is active on susceptible roses that are subject to overhead irrigation.

Southeast Region (Hanson)

General Conditions: Like a broken record, the message remains the same: the drought continues to be the most challenging landscape concern. According to reports, August was the warmest on record and one of the driest. Hanson received 0.62 inches of rain over the past two weeks, most of that from Hurricane Hermine, which did not deliver the much anticipated “downpours” that were predicted. Much more rain is needed as soils remain powder-dry and plants remain drought-stressed exhibiting leaf drop, leaf scorch, wilting, etc.

Albizia julibrissin, Rose-of-Sharon, roses, Campsis radicans, Hydrangea paniculata, Hydrangea quercifolia, Caryopteris divaricata, Butterfly Bush, Lobelia cardinalis, Lobelia syphilitica, Lobelia hybrids, Heliopsis ‘Summer Sun’, Helianthus 'Lemon Queen', Rudbeckia ‘Herbstonne', Japanese anemone, Rudbeckia subtomentosa ‘Henry Eilers’, Rudbeckia triloba, Rudbeckia ‘Goldsturm,’ Sedum sp., Eupatorium sp., Corydalis lutea, Hosta sp., ornamental grasses, Coreopsis ‘Harvest Moon‘ and Phlox paniculata remain in bloom. New England asters are beginning to bloom and Clerodendron trichotomum, Veronicastrum and Echinacea purpurea and hybrids are ending bloom. The fruits of hollies, Kousa dogwood, Cornus controversa, crabapples, Staghorn sumac and Viburnums are beginning to form and color-up; however, the fruits are small on those plants that were not irrigated. On some of the non-irrigated hollies, the developing fruit has dropped due to the drought.

Pests/Problems: Again the drought continues to be the biggest problem. Most towns have initiated some form of water ban and those plants and lawns that have not been irrigated are certainly showing the stress. If clients can water, advise them to water their high value trees and shrubs.

Continue to monitor for Andromeda and azalea lacebugs which can cause significant damage and also monitor for dogwood sawfly larvae, birch sawfly larvae, redheaded pine sawfly larvae and introduced pine sawfly larvae, which can also cause significant damage. Remember, sawflies are not Lepidopteron caterpillars and Bacillus thuringiensis (Bt) will not work on sawflies. Also continue to monitor for Asian Longhorned Beetle (ALB), dogwood sawfly larvae; and viburnum leaf beetle. (See Tawny Simisky’s Insect section of the Landscape Message).

The following insects remain active: wasps, spider mites, boxelder beetles, stinkbugs, leafhoppers, ticks, mosquitoes, biting flies, sunflower moth caterpillars and aphids.

Sod webworm adult moths are active. Continue to monitor lawns for sod webworm larvae and for chinch bug activity.

Once again a cautionary note to be careful and to be on the lookout for ground nesting yellow jackets and the grey paper-like nests of the bald-faced hornet which hang from branches often hidden within the foliage. Just last week, a landscaper relayed the story of one of his employees running into a low-hanging branch while mowing and disturbing a bald-faced wasp nest. The unlucky guy was stung 15 times and had to run quite a distance before the wasps stopped attacking him.

Powdery mildew continues to show up on Monarda, dogwood, Helianthus, Lonicera and garden phlox and tarspot is becoming more pronounced on Norway maple.

Ragweed, Japanese knotweed and jewelweed continue to bloom and pokeweed is setting fruit.

As part of fall cleanup, now perhaps, would be a good time to prune, shear, or remove autumn olive, oriental bittersweet, burning bush and other invasive plants whose fruits are beginning to ripen and are very attractive to birds, which inadvertently through seed dispersal, help spread the plants.

Deer continue to browse plants, especially hosta.

North Shore Region (Beverly)

General Conditions: The weather conditions during this reporting period continued to be hot and dry except for the last few days when the effect of hurricane Hermine brought some rain showers and cooler temperatures. Day temperatures in Beverly during this period ranged from the mid 70s to the mid 80s and night temperatures ranged from the low 50s to the mid 60s. Rain occurred only the last two days of this reporting period. Approximately 0.26 inches of rainfall was recorded at Long Hill. The month of August was hot and dry with rainfall occurring only a few days during the month. A total of 3.21 inches of rainfall was recorded at Long Hill during the month of August. Woody plants seen in bloom include: Japanese pagoda tree (Sophora japonica), Butterfly bush (Buddleia davidii), Blue mist shrub (Caryopteris x clandonensis), Russian Daphne (Daphne x transatlantica) Franklin tree (Franklinia alatamaha), Seven-son flower (Heptacodium miconioides), Rose-of-Sharon (Hibiscus syriacus), Sweet autumn clematis (Clematis paniculata), Trumpet vine (Campsis radicans) and Crepe myrtle shrub (Lagerstroemia sp). Herbaceous plants seen in bloom include: Bush clover (Lespedeza thunbergii), Garden phlox (Phlox paniculata), hostas (Hosta spp.), Autumn joy sedums (Sedum spp.), Joy pye weed (Eutrochium purpureum), Rudbeckia(Rudbeckia hirta), New England aster (Symphyotrichum novae-angliae), Morning glory (Ipomoea purpurea), Japanese anemone (Anemone x hybrida) and Water lily (Nymphaea odorata). Different kinds of annuals are also contributing color in landscapes.

Pests/Problems: Drought conditions continue to persist in this area. The few showers brought about by the effect of hurricane Hermine did not do much to alleviate the drought conditions. Plants are showing signs of drought stress such as wilting, premature leaf drop and early fall color. Powdery mildew was observed on some lilacs and phlox. Crabgrass and other landscape weeds are thriving in the landscape. Goldenrod (Solidago canadensis) is in full broom and providing color on roadsides. Mosquitos have slowed down but they are still active at dawn and dusk. Ticks are also still active. Protect yourself with insect repellent when working outdoors or walking in the woods.

East Region (Boston)

General Conditions: Eastern Massachusetts is experiencing severe drought conditions. We received only 1.62 inches of precipitation during the month of August. So far we have received 0.39 inches in September. This summer season has been the driest in recorded history, having received only 4.05 inches of precipitation from June to August. August has been reported as the warmest on record, with average temperatures reaching 75.5°F. Temperatures thus far in September have been fairly consistent, with highs ranging from 72° F to 78° F, averaging 74° F and lows ranging from 55° F to 67° F, averaging 60° F. Herbaceous perennials continue to bloom and attract pollinators in the meadow and on stream banks. Symphyotrichum pilosum (frost aster) is flowering in natural woodlands. Plants in bloom at this time include Heptacodium miconioides (Seven-Son flower), Koelreuteria paniculata 'September' (golden raintree cultivar), and Rhus chinensis (Chinese sumac). Many trees and shrubs are forming fruit, adding color to the landscape: Magnolia sp. (magnolia), Malus sp. (crabapple), Sorbus sp. (mountain ash), Rosa sp. (rose), and Viburnum sp. (viburnum).

Pests/Problems: Severe drought conditions continue. We received minimal damage from the remnants of tropical storm Hermine and only 0.36 inches of precipitation. Many plants are experiencing early leaf drop. Japanese knotweed (Fallopia japonica) is in full flower and being pollinated by bees; black swallowwort (Cynanchum sp.) fruit has matured and is beginning to disperse. American pokeweed (Phytolacca americana) continue to flower and simultaneously set seed. Viburnum leaf beetle adults have started to lay eggs.

Metro West (Acton)

General Conditions: Hurricane Hermine did nothing to help alleviate the drought situation in this area! It threatened us with strong winds and rain over the Labor Day weekend but did not deliver. A mere 0.17” of rain was recorded for the storm event. The average rainfall for the month of August is 3.72" and the final total for the month was 3.42”. September’s average rainfall is 3.77” and a total of 0.18” has been recorded for the month so far. This summer’s lack of rain and hotter temperatures has taken much of the sting out of our flowering plants. Woody plants seen in bloom this week are Albizia julibrissin (Silk Tree), Buddleia spp. (Butterfly Bush), Heptacodium miconioides (Seven-Son Flower), Hibiscus syriacus (Rose-of-Sharon), Hydrangea paniculata and its many cultivars including 'Tardiva', and Syringa reticulata (Japanese Lilac). A woody vine in bloom is Clematis paniculata (Sweet Autumn Clematis). Contributing even more color and interest to the landscape are some flowering herbaceous plants including: Aster spp. (New England Aster, New York Aster, Smoother Aster, White Wood Aster), Boltonia asteroides (Bolton’s Aster), Cassia marilandica (Wild Senna), Echinacea purpurea (Coneflower), Eutrochium purpureum (Joe Pye Weed), Kirengeshoma palmata (Yellow Wax Bells), Patrinia gibbosa (Patrinia), Perovskia atriplicifolia (Russian Sage), Phlox carolina (Carolina Phlox), C. paniculata (Phlox)and its many cultivars, Rudbeckia fulgida 'Goldsturm' (Black-Eyed Susan), Sedum ‘Rosy Glow’ (Stonecrop),and Solidago spp.(Goldenrod).

Pests/Problems: Drought conditions remain in effect throughout the state with extreme conditions existing for this area and for most of the central and northeastern regions of the state and severe conditions exist for most of the remaining portions of the state as declared by the National Drought Mitigation Center. Signs of plant stress are apparent in the landscape including premature leaf drop and scorch, early fall color and wilting. Powdery mildew is evident on Monarda (Bee Balm), Phlox and Syringa (Lilac). Emergence season is upon us for the Asian Longhorned beetle so continue to check your trees for oviposition sites, frass, exit holes and the beetle. Most importantly, begin to scout for the Asian Longhorned beetle! Monitor the 12 host genera: Acer (Maple), Betula (Birch), Ulmus (Elm), Salix (Willow), Aesculus (Horsechestnut), Fraxinus (Ash), Platanus (Plane Tree), Populus (Poplar), Sorbus (Mountain Ash), Albizia (Mimosa), Cercidiphyllum (Katsura) and Keolreuteria (Golden Raintree) for this invasive pest.

Central Region (Boylston)

No report available this week.

Pioneer Valley Region (Amherst)

General Conditions: Summer has unofficially ended as we celebrated Labor Day, but the drought continues on without any sign of abatement. According to the Northeast Regional Climate Center, the Pioneer Valley received 50–75% normal precipitation during the months of June, July and August. That’s 4–6″ below normal for most of the eastern valley while locations west of the Connecticut fared slightly better with a 2–4″ deficit. If we examine the six month departure (March through August), nearly all of Franklin, Hampshire and Hampden counties have recorded a 7–9″ rainfall deficit. Hopes for even trivial rainfall from tropical storm Hermine were dashed as the storm tracked out to sea, bringing only increased winds to further desiccate our parched landscape. Of the 351 cities and towns in the Commonwealth, 168 have water use restrictions in place. The most egregious misuse of water on the landscape is lawn watering with poorly calibrated sprinklers during mid-day hours. The rainfall we received over a four-day span in late July and early August did help to green up lawns and provide perennials with some meaningful rain but it’s a distant memory at this point. Some landscape and forest trees and shrubs are beginning to senesce for the season, after suffering through above-average heat for most of the summer in addition to the drought. Birch leaves are yellowing and maples (red, sugar and Norway) have browning leaf margins and are shedding leaves. Katsura and Stewartia continue to lose foliage prematurely, leaving some upper canopies barren already. Horsechestnuts that appear to be suffering from Guignardia leaf blotch are mostly drought-scorched. Numerous very old rhododendrons and azaleas on the UMass campus have wilted and curled foliage. Temperatures have cooled slightly since the last reporting period with highs now peaking in the lower 80s and nighttime temperatures settling into the upper 50s to low 60s. Cooler temperatures and shorter days will reduce the demand for water from landscape plants.

Pests/Problems: Drought stress continues to be our number one concern for trees and shrubs as we approach the dormant period. Drought stress can reduce winter hardiness and weakens natural defenses leaving plants susceptible to an array of opportunistic insect pests and pathogens. While many individuals have irrigated during this prolonged dry period, some are not irrigating properly and drought stress has developed as a result. Depending on the settings, lawn sprinklers and soaker hoses must run for long periods of time to properly irrigate trees and shrubs. In most cases where irrigated plants are suffering water shortages, sprinklers and hoses are run for only short intervals (e.g. 15–20 minutes) and are not providing adequate water to the roots. Continue to scout and treat for the spruce spider mite. This destructive pest often reemerges in September when temperatures cool. Spider mites are easily washed away from infested needles by rain and their populations build up rapidly during extended dry periods. Oak spider mite has been abundant and many oaks in the valley are showing the characteristic bronze foliage from heavy feeding. Lacebugs have been locally abundant on rhododendron, azalea and Andromeda. Anthracnose fungi, while not especially common this summer due to the dry conditions, are still widespread on the landscape. These fungi become active again in autumn once temperatures cool. If we do experience significant rainfall this month, anthracnose fungi can cause additional damage to drought-stressed trees. A number of weak, secondary pathogens are taking advantage of stressed foliage at this time. Eye midges are abundant right now, creating a tremendous annoyance during outdoor activities. Wasps are becoming more aggressive and care should be taken to avoid disturbing any nests.

Berkshire Region (Great Barrington)

General Conditions: Since August 21st, total rainfall for this monitoring site in Great Barrington up to September 7th amounted to 0.03 inches. The current (as of Sept. 7) precipitation deficit for the year is just over 7 inches. The past two weeks have been the driest of the growing season. How dry? So dry that rainfall events are often measured in drops rather than inches. Soils, whether coarse and sandy or clayey, are dry and powdery. While many plants – woody and herbaceous - in the landscape are wilting or drying up, hydrangeas seem to be holding up very well and cultivars of Hydrangea paniculata have put on a terrific floral display and continue to do so.

Pests/Problems: Insect pests of plants are few, perhaps due to the drought, but aphids are prominent on many plants. Oak lace bug adults are active. Ticks have been few as have mosquitoes. Besides drought effects, the biggest problem in landscapes may be browsing by deer, rabbits, chipmunks, woodchucks, and especially voles. Wildlife seem to be drawn to the more succulent plants found in home landscapes. Drought related problems include severe wilting of un-irrigated herbaceous perennials, premature color change of woody plant foliage, and leaf drop. Crabapples are particularly prone to leaf drop and many are denuded at this point. This is due not only to the dry conditions but also to foliar diseases, i.e. apple scab and cedar apple rust. Roses infected with black spot are also dropping leaves early. Powdery mildew is common on many plants including lilacs, ninebark, phlox, and dahlias. Unirrigated lawns have substantial browning.

Regional Scouting Credits

  • CAPE COD REGION - Roberta Clark, UMass Extension Horticulturist for Barnstable County - Retired, reporting from Barnstable.
  • SOUTHEAST REGION - Deborah Swanson, UMass Extension Horticulturist for Plymouth County - Retired, reporting from Hanson.
  • NORTH SHORE REGION - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from the Long Hill Reservation, Beverly.
  • EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists, reporting from the Arnold Arboretum, Jamaica Plain.
  • METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
  • CENTRAL REGION  -  Joann Vieira, Superintendent of Horticulture, reporting from the Tower Hill Botanic Garden, Boylston.
  • PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from UMass Amherst.
  • BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

Recent pathogens of interest seen in the UMass Extension Plant Diagnostic Lab:

Rose rosette virus (RRV) on knockout rose (Rosa ‘Radrazz’ KNOCK OUT). There are roughly 450 roses in a mass planting at a residential property. This season, dozens of plants exhibited symptoms of the disease, which included: canes that were magenta with numerous rubbery thorns, witches' brooming (stunted, bushy clusters of canes), undersized and deformed foliage that was dark red in color and canopy dieback. Once infected, the virus spreads throughout the plant, including the roots, and plants often die within a few years. The virus is spread through infected rootstock and an eriophyid mite.

Yellowing and premature shedding of leaves on black birch (Betula lenta) caused by anthracnose (Discula sp.) and a secondary stem cankering pathogen (Steganosporium). Mature tree that resides in an perennial bed on the edge of a forest. Symptoms of decline were not observed by the homeowner in previous years. Little is known about Steganosporium, which can also be found attacking stems and small branches of declining maples. Drought stress is also a likely contributor to the decline as birch are shallow-rooted and sensitive to drought conditions.

Decline and dieback of eastern hemlock (Tsuga canadensis) caused by the hemlock rust mite (Nalepella tsugifoliae) and stem cankering from Phomopsis. Tree is approximately 15-years-old and has been provided with supplemental water this season from a lawn sprinkler. Several other hemlocks in the area are completely defoliated but this tree did not show symptoms of decline in previous years. The hemlock rust mite actively feeds in late winter, early spring and in autumn. Drought stress from 2015 and 2016 may be an additional stress as lawn sprinklers often fail to provide adequate water to tree roots.

Marginal leaf scorch of kousa dogwood (Cornus kousa) caused by Discula destructiva. Two trees, both 20-years-old, were transplanted at a residential site two years ago. Planted in full sun with irregular irrigation during the first year of establishment. While kousa dogwood is highly resistant to dogwood anthracnose, a marginal leaf scorch can develop on stressed trees.

Transplant shock and secondary foliar blight of flowering pear (Pyrus calleryana ‘Cleveland Select’). Tree is 4-5” in diameter and was transplanted in early August. At the time of planting, the tree appeared healthy but within two weeks of transplanting the foliage began to senesce and drop. The tree was hand-watered every day since planting. Several secondary fungi were detected on the foliage but none are suspected of acting as the primary cause of the observed symptoms.

 Construction Injury: It took nine years, but the black walnut (left) and yellowwood (right) that were damaged by construction of the Studio Arts building on the UMass campus have finally succumbed to their injuries. Root compaction, severing and burying of the root flare resulted in gradual canopy dieback that was accelerated by this season's drought.    Drought Stress: Scorched leaf margins on a three-flowered maple (Acer triflorum) due to drought stress. The tree was planted in 2000 on the UMass campus and has been healthy in previous years.

Report by Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass Amherst.

Insects

Woody ornamental insect and non-insect arthropod pests to consider, a selected few:

  • Andromeda Lacebug: Stephanitis takeyairemains active on Japanese Andromeda. Inspect plants known to have S. takeyai in the past (or exhibiting yellow stippling on the upper leaf surface) and inspect undersides of leaves for this season’s lacebugs. Before populations become too large, treat with a summer rate horticultural oil spray as needed. Be sure to target the undersides of the foliage in order to get proper coverage of the insects.
     
  • Asian Longhorned Beetle, Anoplophora glabripennis, ALB adults continue to be active. Look for the insect itself (a shiny black bodied beetle with white spots and long antennae with black and white bands) or signs of an ALB infestation which include perfectly round exit holes (about the size of a dime), shallow oval or round scars in the bark where a female has chewed an egg site, or sawdust-like frass (excrement) on the ground nearby host trees or caught in between branches.

    The regulated area for Asian longhorned beetle is 110 miles2 encompassing Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn. If you believe you have captured an Asian longhorned beetle or have seen damage caused by this insect, such as exit holes, on susceptible host trees like maple, please call the Asian Longhorned Beetle Eradication Program office in Worcester, MA at 508-852-8090 or toll free at 1-866-702-9938. To report an Asian longhorned beetle find online or compare it to common insect look-alikes, visit: http://massnrc.org/pests/albreport.aspx or https://www.aphis.usda.gov/pests-diseases/alb/report.
     
  • Azalea Lacebug: Stephanitis pyrioidesis active on evergreen azaleas. This insect may be more damaging on plants located in warm, sunny locations. Like andromeda lacebug, this insect will remain active into the fall. Plants in hot, dry, sunny sites may be severely impacted at this time. Horticultural oil sprays targeting the undersides of the foliage can be very effective for this pest.
  • Emerald Ash Borer (EAB): Agrilus planipennis readily attacks ash (Fraxinus spp.) including white, green, and black ash and has also been found developing in white fringe tree (Chionanthus virginicus). For a map of the known locations of emerald ash borer in the state, as well as further information about this insect, please visit: https://ag.umass.edu/fact-sheets/emerald-ash-borer.
  • Fall Home-Invading Insects: Various insects, such as ladybugs, boxelder bugs, seedbugs, and stink bugs will begin to seek overwintering shelters in warm places, such as homes, throughout the next couple of months. While such invaders do not cause any measurable structural damage, they can become a nuisance especially when they are present in large numbers. While the invasion has not yet begun, if you are not willing to share your home with such insects, now should be the time to repair torn window screens, repair gaps around windows and doors, and sure up any other gaps through which they might enter the home.
  • Hemlock Woolly Adelgid: Adelges tsugae is present on eastern and Carolina hemlock and is in its summer dormant period which will last until approximately mid-October. Dormant nymphs can be treated throughout the summer with a horticultural oil spray at the summer rate, however be careful to follow all label instructions to avoid injury to the plant. Avoid using oils when temperatures are close to or above 90°F and when humidity is high.
  • Redheaded Pine Sawfly: remains active at this time. This caterpillar-like insect is yellow with rows of black spots and a rust-colored head capsule. Clusters of these hymenopterans can be seen feeding on pines and will continue into the autumn months. Inspect needle tips for clusters of larvae. Prune out or destroy with a gloved hand in the case of small infested areas. Spinosad is effective against these larvae, whether younger or older.
  • Spruce Spider Mite: Oligonychus ununguis, a cool season mite, has resumed its activity following a break during the hottest days of summer. This particular pest may be active throughout October. Inspect for new yellow stippling on spruce, fir, and hemlock. Population size can be monitored by shaking branches over white pieces of paper and then inspecting with a hand lens. If you are seeing more than 10 mites per tap, treat with a horticultural oil at the summer rate if necessary. All management should strive to preserve predatory mites, as they are the most effective managers of these pests.
  • Caption: Two-marked treehopper, Enchenopa binotata, on hoptree. White, sticky masses of froth are secreted by the females which coat the area where eggs have been laid in slits made in the bark. (Photo: Simisky) Two-Marked Treehopper: Enchenopa binotata is present on hoptree, black walnut, butternut, black locust, viburnum, redbud, bittersweet, and Wisteria species. While this particular treehopper has been active for quite some time this season, adult females began laying their eggs in early August and will continue until we have our first frost. Females cut a slit in the host twig and lay small clusters of eggs (4-6) just beneath the bark. The locations where egg laying has occurred are quite apparent at this time as the females will then coat the slits with a white, sticky, frothy substance which serves to protect the eggs from parasites as well as harsh environmental conditions. These froth deposits can be quite visually striking, as they are frequently made in great numbers. Management of this insect is usually not necessary as damage is not significant.

Concerned that you may have found an invasive insect or suspicious damage caused by one? Need to report a pest sighting? If so, please visit the Massachusetts Introduced Pests Outreach Project: http://massnrc.org/pests/pestreports.htm.

A note about Tick Awareness: deer ticks (Ixodes scapularis), the American dog tick (Dermacentor variabilis), and the lone star tick (Amblyomma americanum) are all found throughout Massachusetts. Each can carry their own complement of diseases. Anyone working in tick habitats (wood-line areas, forested areas, and landscaped areas with ground cover) should check themselves regularly for ticks while practicing preventative measures. Have a tick and need it tested? Visit the web page of the UMass Laboratory of Medical Zoology (www.tickdiseases.org) and click on the red Test a Tick button for more information.

Report by Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program

Management Practices

Plant of the Week: Campsis radicans

Campsis radicans is a good example of a plant for which the positives (late summer blooms, popular with hummingbirds) and negatives (aggressive nature) need to be considered when using in the landscape. Campsis radicans is a vigorously growing woody vine native to the southeastern United States. It is very important to keep in mind the aggressive nature of the plant when choosing Campsis radicans. The suckering habit and aggressive growth require frequent pruning to control the plant. Plants bloom best in full sun and do well in average (or even poor) soil.

The common name, trumpet vine or trumpetcreeper, comes from the trumpet shaped orange/scarlet flowers from July to September. Flowers are 2-3” long and are in terminal clusters of 4-12 on new growth. Flowers are very attractive to hummingbirds. Cultivars offer yellow, apricot, and red flowers.  Leaves are pinnately compound, are 6-15” long, and have 11 leaflets. The 3-5” long bean-like seed pods split open to release seeds.

Vines cling to surfaces via aerial rootlets and will climb/cover trees or structures. The weight of the plant requires a sturdy structure. Trumpet vine can also be used to cover rock piles or old tree stumps. Care should be taken around plants as leaves can cause itching and redness with contact.

Plant of the Week: Campsis radicans    Plant of the Week: Campsis radicans    Plant of the Week: Campsis radicans

Report by Mandy Bayer, Extension Assistant Professor, UMass Stockbridge School of Agriculture

Landscape Turf

Insects

Sod webworms

I was mowing my lawn late yesterday afternoon, and was struck by the number of sod webworm adults that were flying aimlessly about, just above the turf canopy. This was by far the largest flight of webworms I have ever noticed in my yard, although I see them every September. Interestingly, Whitney Cranshaw (my counterpart at Colorado State University) had recently reported a similar outbreak in Colorado. He and I are in agreement that the heavy flight should be viewed more as a curiosity than a point of concern. Given the number of adults I saw flying, there must have been a considerable number of caterpillars feeding about two or three weeks ago, and yet I did not see any damage in my lawn that could be attributed to caterpillar feeding. (There was plenty of drought stress and dormant turf but no obvious damage from webworms.) So I do not believe the heavy moth flight warrants any action at this time. I will monitor carefully next spring to see whether there is an increase in caterpillar activity in April or May, but I doubt there will be.

Turfgrass ants

I also saw very large numbers of turfgrass ants emerging from mounds in my lawn. When I got out my camera with the macro-lens and looked closely, I could see that there was a line of adults bubbling to the top of the burrow and stumbling out into the air. All of the ants were winged. This was that annual "nuptial flight". In most cases the ants emerge within a very short period of time from a given colony (often within a 24 hour period) and mate. The males do not live long after mating, while the females shed their wings and burrow a foot or more into the soil. They will begin to produce a new colony the following spring.

Some of my colleagues have suggested treating turf areas during a nuptial flight, with the hope of eliminating the emerging queens, but I personally believe it makes more sense to wait until next spring and treat new mounds as soon as they become apparent, if treatment is deemed necessary. Remember that turfgrass  ants spend much of their time preying on eggs and tiny larvae of some grubs and caterpillars, among other things, and so could be considered beneficial insects. If only we could teach them to stop producing the disruptive mounds!!!
And note that turfgrass ant mounding activity is normally only a problem on short-mown turf like golf course fairways, tees, and edges of greens.  While some people occasionally express concern about turfgrass ant activity in home lawns, I urge those folks to consider the benefits of predatory ants. Because the height of cut on a lawn is so much higher, the mounding activity should be minimally disruptive. (European fire ants are a very different species and can cause very painful stings, but appear to be fairly sporadic in their distribution in southern New England.)

Grub update

I received grub samples from two very different settings this week, and they have confirmed what I was suspecting.

The first sample came from an unirrigated rough at a golf course near Amherst. There were very few grubs in the area, and the only ones we found were near a sprinkler head. The ground otherwise was powder-dry. The grubs were late first instars and early second instars. Another sample came from irrigated athletic fields in the 495 corridor just south of the Turnpike. The affected areas were very heavily infested - at least 15 to 20 grubs per square foot. More than half the grubs were already third instars, feeding very aggressively. So... if you are managing irrigated turf, check NOW to see whether grubs are active on your properties. You are running out of time to apply a curative treatment. The larger the grubs are, the harder they will be to control. If you are managing unirrigated turf, this is also a good time to monitor to see whether you have any small grubs present. They are resilient critters, and if we get a little relief and some rain, the potential is there for some outbreaks.

Report by Dr. Pat Vittum, Professor and Extension Entomologist, UMass Stockbridge School of Agriculture and Associate Director, UMass Center for Agriculture, Food and the Environment

Other Relevant News/Pest Alerts

TAP is a program administered by the USDA - Farm Service Agency (FSA) and provides monetary assistance to producers to replace trees, shrubs and vines damaged by a natural disaster.

Don't let the "Tree" in the Tree Assistance Program throw you off.  TAP covers a variety of nursery products including ornamental trees and shrubs.  Given the extent of the drought this year there may be growers who experienced a qualifying loss to be eligible for TAP coverage.  Growers who have questions about TAP and eligible crops are encouraged to contact their local USDA-FSA Office.

Tree Assistance Program (TAP)

TAP Fact Sheet


Additional Resources

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For a complete listing of upcoming events, see our Upcoming Educational Events page.

For commercial growers of greenhouse crops and flowers - Check out the New England Greenhouse Update website

For professional turf managers - Check out Turf Management Updates

For home gardeners and garden retailers - Check out home lawn and garden resources. UMass Extension also has a Twitter feed that provides timely, daily gardening tips, sunrise and sunset times to home gardeners, see https://twitter.com/UMassGardenClip

Diagnostic Services

A UMass Laboratory Diagnoses Landscape and Turf Problems - The UMass Extension Plant Diagnostic Lab is available to serve commercial landscape contractors, turf managers, arborists, nurseries and other green industry professionals. It provides woody plant and turf disease analysis, woody plant and turf insect identification, turfgrass identification, weed identification, and offers a report of pest management strategies that are research based, economically sound and environmentally appropriate for the situation. Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. For sampling procedures, detailed submission instructions and a list of fees, see Plant Diagnostics Laboratory

Soil and Plant Nutrient Testing - The University of Massachusetts Soil and Plant Nutrient Testing Laboratory is located on the campus of The University of Massachusetts at Amherst. Testing services are available to all. The function of the Soil and Plant Nutrient Testing Laboratory is to provide test results and recommendations that lead to the wise and economical use of soils and soil amendments. For complete information, visit the UMass Soil and Plant Nutrient Testing Laboratory web site.   Alternatively, call the lab at (413) 545-2311.

Ticks are active at this time! Remember to take appropriate precautions when working and playing outdoors, and conduct daily tick checks. UMass tests ticks for the presence of Lyme disease and other disease pathogens. Learn more