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Landscape Message: Jun 12, 2015

Jun 12, 2015
Issue: 
13

UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Green Industry professionals in the management of our collective landscape. Scouts compile and record environmental and phenological data for locations throughout Massachusetts to aid in the monitoring of plant and pest development, the planning of management strategies, and the creation of site-specific records for future reference.  Detailed reports from Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. UMass Extension has updated the following issue to provide timely management information and the latest regional news and environmental data.

The Landscape Message will be updated weekly April through June. The next message will be available on June 19. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list.

Scouting Information by Region

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The weather was on the cooler side for this reporting period. While many areas in the rest of the State received rainfall, the Cape only received some passing showers. In Marstons Mills, 0.07” fell in a brief shower on Saturday, June 6. Other areas of the Cape either had no rain or perhaps a brief shower. Soils are very dry. In the perennial border, Peonies are beginning to bloom, along with Siberian Iris and Baptisia that are in full bloom. Irrigated lawns are green and mowing season is in full swing. Pests/Problems: The lack of adequate rainfall is the largest problem in the landscape. Newly planted materials need deep and regular irrigation as this moderate drought continues. Flagging has been observed on well-established perennials.  The winter moth caterpillar is done for this year, which saw widespread damage to many oaks and maples. Pockets of gypsy moth caterpillars continue to feed. Nantucket pine tip moth can be seen flying around the candles of pitch and other 2 and 3 needle pines in the early evening. Cottony Taxus scale is in the egg laying stage and can be observed on the undersides of holly leaves and on Taxus needles. Rose slug sawfly is skeletonizing rose foliage. Spittlebugs are active. Along with leafhoppers. Monitor pitch pines for Black turpentine beetle. June beetles are flying into window screens at night. Ants, carpenter bees, and wasps are all active. Mosquito populations are high and biting! Deer tick nymphs are active. Be sure to do thorough tick checks at the end of the day. Use DEET as a repellent or treat clothing with permethrin products that are labeled for that use.

Southeast Region (Hanson)

General Conditions: Cool weather started the week out with day-time temperatures in the 50s, and a one night low of 42 degrees. The weather then warmed up into the low – mid 70s. Hanson received 0.03 rain this past week and soils are drying out. Sinocalycanthus chinensis, Cladrastis kentukea, Magnolia virginiana (Sweetbay magnolia), Liriodendron tulipifera (Tuliptree), Rutgers’ Hybrid dogwoods, Cornus kousa, Syringa x prestoniae ‘James Macfarlane’, Syringa ‘Miss Kim’, Robinia hispida (bristly locust), Rhododendron sp., Calycanthus, Cotinus obovatus, Cotinus coggygria, Indigofera sp., Abelia mosanensis, Beautybush, Weigela florida, Physocarpus opulifolius (Eastern Ninebark), Lonicera sempervirens, Rosa rugosa, Clematis sp., Stephanandra incisa ‘Crispa’, Valeriana officinalis (Garden Heliotrope), Iris sibirica, Bearded Iris, Baptisia australis and Baptisia hybrids, Tradescantia, Lupines, Persicaria polymorpha, Lamium, Lamiastrum galeobdolon, Foxgloves, Allium, Nepeta sp., early daylilies, Anemone canadensis, Thalictrum aquilegifolium, Corydalis lutea, Salvia ‘May Night’, Aquilegia sp. (Columbine), Amsonia sp., Oriental poppies, Peonies, Doronicum sp., Dianthus sp., Arisaema ringens, Dicentra eximia (Fringed Bleeding Heart), Polygonum bistorta ‘Superbum’ and Alchemilla mollis are in full bloom. Rosa ‘Linda Campbell and other landscape roses, Hypericum androsaemum ‘Mrs. Gladis Brabazon’, Spiraea sp. and Aruncus dioicus are beginning bloom. Aesculus x carnea (Red Horsechestnut), Chionanthus virginicus, Buglossoides purpurocaerulea and Mazus reptans are ending bloom.  Pests/Problems: Trees defoliated by winter moth caterpillars are starting to re-foliate, and as recommended before, remind clients to water these trees, as they struggle to survive. Trees defoliated by insects, early in the season, will usually put out new leaves but they need water to do this and need to avoid further stress and decline from drought. Several people have commented that winter moth damage was heavier than in previous recent years, with reports that the Dartmouth - Westport areas were seeing increased defoliation than in previous years. One explanation for this according to Jeff Boettner from Dr. Joe Elkinton’s UMass lab is that “the cold spring meant buds opened slowly, giving winter moth caterpillars more time to do damage early”.  Gypsy moth caterpillars are active and there appear to be “pockets” where they are in higher numbers than in previous years. Many oaks in the area appear not to be re-foliating; however, this “appearance” may actually be due to gypsy moth caterpillars feeding on the new foliage and few remaining leaves. In Halifax, MA, gypsy moth caterpillars were observed feeding on dwarf Alberta spruce, not their favored host plant. However, when their favorite host plants (oak, etc.) are in short supply (due to defoliation by winter moth caterpillars, etc.), then gypsy moth caterpillars have been known to feed on spruce, pine etc.  Oriental beetles have started to emerge. The metallic, mottled brown, grey, black beetles are similar in shape, although slightly smaller in size, than Japanese beetles. The larvae of Oriental beetles feed on the roots of turf; however, the adults do feed on plant foliage.  Colorful (orange-red with black), young, Four-lined plant bug nymphs were observed feeding on the new foliage of a variety of perennials. Adults are gold-green, with 4 longitudinal black stripes.  Four-lined plant bug is a piercing-sucking insect whose feeding causes numerous, small, round, brown-black spots on new foliage. Some gardeners mistake these symptoms as a disease. The damage is usually seen before the insects, which move quickly. Damage is mostly cosmetic and will be often be found on the new growth of a wide-range of herbaceous and woody plant material.  Cottony Camellia scale (aka: Taxus Scale), Fletcher’s Scale and Taxus mealybug were observed on Taxus. Monitor Taxus for these pests and manage as needed.  Lysimachia sawfly, a silvery-grey caterpillar-like pest, has emerged and was observed feeding on Lysimachia ciliata ‘Purpurea’; this pest will skeletonize the foliage of this plant. Bacillus thuringiensis (Bt) does not work on sawfly larvae.  Roseslug sawfly remains active, although in low numbers as it winds-down for the season. Untreated plants appear browned and scorched and unfortunately, this is the time when many gardeners begin to notice the plants have a “problem”, when most of the damage has already occurred. Plants that look badly may be cut back and new growth should begin.  White-spotted pine sawyer is, or soon will be, active. This insect is often mistaken for the Asian longhorned beetle and some of your clients may wonder if this is the Asian longhorned beetle. The following web site displays many of the Asian longhorned beetle “look-alikes”: https://ag.umass.edu/sites/agcenter/files/pdf-doc-ppt/ALB_lookalikes.pdf Adobe PDF icon Termites are swarming outdoors.  The following insects continue to be active: Iris bud fly maggot, deer ticks, dog ticks, pine spittlebugs, ants, spider mites, hemlock woolly adelgid, earwigs, lily leaf beetles (adults, larvae and eggs), leafhoppers, stinkbugs, mosquitoes, wood cockroaches, slugs, snails, green fruitworm caterpillars and azalea whitefly.  With the previously drier weather, it seems, for now, that there are fewer slugs and snails than usual. However, mosquitoes are numerous.  Reports of people being bitten by deer ticks continue, so remember to take precautions to avoid becoming a “deer tick-bite victim”; UMass tests (for a fee) for the bacteria carried by deer ticks that cause diseases. For more information, go to: http://www.tickdiseases.org/  Beneficial insects like the iridescent, bright-green tiger beetle, lady beetles and hover flies are also active.  Azalea leaf galls (Exobasidium vaccinii) are becoming large and covered with white spores. Remove the galls and place in the trash.  Witchhazel blight (Phyllosticta hamamelidis) continues to be a problem on foliage on ‘Arnold Promise’ witchhazel, turning the foliage brown.  The following weeds are in bloom: Multiflora rose, hawkweed, oxeye daisy, red and white clover, Rumex (dock) and numerous grasses. Deer, turkeys, chipmunks, voles, and squirrels remain active. White pine pollen is just about done for the year! Yay! It appears to be another banner year for weeds. Oxalis and clearweed have also emerged and now is a good time to manage all weeds before they become larger and set seed.

North Shore Region (Beverly)

General Conditions: The first few days of this reporting period we had unseasonably cooler weather with night temperatures in the 40s. Long Hill gained 59 growing degree days (GDD) during this period, far less than what was gained in previous reporting periods. Approximately 0.03 inches of rainfall was received during this period. However because of the rains received during the previous period, the lawns that had started to brown have greened up and are staying green. Woody plants seen in bloom include: Toucan azalea (Rhododendron ‘Toucan’), Jonathan Shaw Rhododendron, Flame azalea (Rhododendron calendulaceum), Kousa Dogwood (Cornus Kousa), Doublefile viburnum (Viburnum plicatum var. tomentosum), Slender Deutzia (Deutzia gracilis), Summer snowflake doublefile viburnum (Viburnum plicatum ‘Summer Snowflake'), Meyer lilac (Syringa meyeri), Cranberrybush viburnum (Viburnum trilobum), Arrowwood viburnum (Viburnum dentatum), Japanese snowbell (Styrax japonicus), Fragrant snowbell (Styrax obassia), Black locust (Robinia pseudoacacia), Fringe tree (Chionanthus virginicus), Beauty Bush (Kolkwitzia amabilis), Chinese Neillia (Neillia Chinensis), Mountain Laurel (Kalmia latifolia), and Ninebark (Physocarpus opulifolius) . Herbaceous plants in bloom include: Peonies (Paeonia sp.), Fetterbush (Leucothoe fontanesiana), Redleaf rose (Rosa glauca), Baptisia (Baptisia australis), Nepeta (Nepeta Sp.), Blue star (Amsonia hubrichtii), Columbine (Aquilegia sp.), Geranium (Pelargonium spp.), Aruncus (Aruncus dioicus), Corydalis (Corydalis lutea), Allium (Allium sp.) and Ox-eye daisy (Leucanthemum vulgare).  Pests/Problems: Leaf and flower galls (Exobasidium vaccinii) have been seen on azalea. Prune the galls and discard before they start to release spores. Also seen on azalea were azalea sawfly larvae feeding on leaf blades. The larvae eats all the leaf blade leaving only the main vein. If you have only a few sawfly larvae you can pick them by hand and throw them in a bucket with soapy water and they will die. If you have many of them consider applying a registered pesticide such as Spinosad. Mosquitoes and ticks are still very active. Protect yourself with insect repellent when working outdoors especially at dawn and at dusk. Multiflora rose (Rosa multiflora ) and wild raspberry (Rubus rosifolius) weeds are in full bloom and are easy to identify.

East Region (Boston)

General Conditions: Temperatures over the last week have been cooler than normal but have steadily increased. Highs ranged from 60º F on the 3rd to 79º F on the 9th. We experienced cool evenings over the last week with temperatures in the mid-40s. The average low was 50º F and the average high 68º F. Despite numerous chances for thunderstorms and precipitation, we gained only 0.05 inches of rain this week. The cooler temperatures at the beginning of the week resulted in low accumulations of GDDs, we gained only 2.5 and 3.0 GDDs on the 3rd and 4th respectively, which would be expected of early spring weather; the warmer temperatures on the 8th and 9th resulted in 13.5 and 21.5 GDD accumulated, respectively. For the week, we have gained only 64.5 GDDs bringing us up to 526.5 on the year. Currently in bloom: Aruncus dioicus (goatsbeard), Buddleia alternifolia (fountain butterflybush), Carya ssp. (hickory), Chionanthus retusus (Chinese Fringe Tree), C. virginicus (Fringe Tree), Clematis spp. (Clematis), Cornus coreana (Korean dogwood), Cornus kousa (Kousa dogwood), Cotinus coggygria (common smokebush), Deutzia x magnifica ‘Formosa’ (showy deutzia), Iris versicolor (blue flag iris), Kalmia latifolia (mountain laurel), Kolkwitzia amabilis (beautybush), Magnolia macrophylla (bigleaf magnolia), M. sieboldii (Oyama magnolia), M. virginiana (sweetbay magnolia), Paeonia ssp. (peony), Physocarpus opulifolius (common ninebark), Potentilla fruiticosa (potentilla), many Rhododendron sp. cultivars (Rhododendron), Rosa rugosa (rugosa rose), R. 'Knockout' (The Knockout family of Roses) and many other hybrid cultivars of rose, Spirea japonica (Japanese spirea), Spiraea spp. (spirea) and Syringa reticulata (Japanese tree lilac).  Pests/Problems: The lack of precipitation is once again becoming evident throughout the landscape. Many noxious weeds are taking advantage of these conditions and are thriving. Black swallowwort (Cynanchum louiseae) continues to flower. Yellow flag iris (Iris pseudacorus) is in full bloom as is glossy buckthorn (Frangula alnus). Crabgrass is flourishing in any open bare areas in turf. Leaf miner (Profenusa canadensis) has had a banner year on many hawthorns (Crataegus sp.). Gypsy moth (Lymantria dispar) caterpillars are active. Imported willow leaf beetle (Plagiodera versicolora) is active on many willows (Salix spp.). Galls are evident throughout the landscape on maples, oaks, witch hazels, lindens and other woody plants. Creeping charley galls (Liposthenes glechomae) can be found on Glechoma hederacea. Pine sawyer beetles (Monochamus sp.) have emerged and are very active at this time of year.

Metro West (Acton)

General Conditions: With a few cool nights with low temperatures in the 40’s, the area gained just 80 GDD during this recording period.  With the recent rain recorded at 0.16", lawns are staying green and have lost that August look from two weeks ago. Woody plants seen in bloom this past week are Catalpa speciosa (Northern Catalpa), Chionanthus retusus (Chinese Fringe Tree), C. virginicus (Fringe Tree), Cladrastis kentukea (Yellowwood), Cornus kousa (Kousa Dogwood), C. sericea (Redosier Dogwood), Cotinus coggygria (Common Smokebush), Kalmia latifolia (Mountain Laurel), Kolkwitzia amabilis (Beautybush), Ligustrum spp. (Privet), Philadelphus coronarius (Sweet Mock Orange), Physocarpus opulifolius (Common Ninebark), P. opulifolius 'Summer Wine' (Summer Wine Ninebark), Potentilla fruiticosa (Potentilla), P. tridentata (Cinquefoil), Rhododendron spp. (Rhododendron and Azalea), Rosa rugosa (Rugosa Rose), R. 'Knockout' (The Knockout family of Roses), Rosa spp. (Rose), Spirea japonica 'Alpina' (Daphne Spirea), Spiraea spp. (Spirea), Syringa reticulata (Japanese Tree Lilac), Viburnum dentatum (Arrowwood Viburnum), V. plicatum var. tomentosum (Doublefile Viburnum), V. sargentii (Sargent's Viburnum) and Weigela florida (Old Fashioned Weigela). Woody vines in bloom are: Clematis spp. (Clematis) and Lonicera sempirvirens (Trumpet Honeysuckle). Contributing even more color and interest to the landscape are some flowering herbaceous plants including: Achillea millefolium (Yarrow), Ajuga reptans (Bugleweed), Alchemilla mollis (Lady's Mantle), Allium giganteum (Giant Onion), A. schoenoprasum (Chives), Amsonia hubrichtii (Arkansas Blue Star), Aquilegia spp. (Columbine), Baptisia australis (False Blue Indigo), Centaurea montana (Cornflower), Chrysogonum virginianum (Green and Gold), Clematis recta 'Purpurea' (Clematis), Coreopsis sp. (Tickseed), Dianthus deltoides (Maiden Pink), Dictamnus albus (Gas Plant), Filipendula sp. (Meadow Sweet), Geranium cantabrigiense 'Biokovo' and 'Cambridge' (Hardy Cranesbill), G. maculatum (Wild Geranium), G. macrorrhizum (Bigroot Geranium), G. sanguineum (Cranesbill Geranium), Hemerocallis 'Stella D'Oro' (Daylily) and H. spp. (early blooming Daylily), Heuchera spp. (Coral Bells), Iris germanica (Bearded Iris), I. psuedacorus (Yellow Flag iris), I. versicolor (Blue Flag Iris), I. sibirica (Siberian Iris), Leucanthemum sp. (Shasta Daisy), Lupinus 'Russell Woodfield Hybrids' (Lupine), Nepeta spp. (Ornamental Catmint), Oenothera macrocarpa (Ozark Sundrops), Paeonia spp. (Peony), Perovskia atriplicifolia (Russian Sage), Phlox divaricata (Canadian Phlox), Polemonium reptans (Jacob's Ladder), Salvia nemerosa (Salvia), Saponaria ocymoides (Rock Soapwort), Stylophorum diphyllum (Wood Poppy), Thymus praecox (Thyme), Tradescantia sp. (Spiderwort), and Veronica umbrosa 'Georgia Blue' (Speedwell).  Pests/Problems: Pine Sawyer Beetles have recently emerged and are often very confused with the Asian Longhorned Beetle; the Pine Sawyer can be distinguished by the single white dot found at the base of its wing cover. Rosa multiflora is in full bloom and is now easy to detect growing in and amongst other trees and shrubs.

Central Region (Boylston)

General Conditions: Cooler temperatures returned and much needed rain has helped to keep new transplants and turf in good shape. Many plants are now in bloom including Peonies (Paeonia sp.), Perennial Salvia (S. nemorosa ‘Ostfriesland, S. ‘Blue Hill’), Columbine (Aquilegia sp.), Hardy Geranium (Geranium ‘Rozanne’ and others), Dianthus ‘Feuerhexe’ and others, Bearded Iris, Yellowwood (Cladrastis kentukea), Styrax japonica, Tulip Tree (Liriodendron tulipifera), Ashe’s Magnolia (Magnolia macrophylla subsp. ashei).  Pests/Problems: Azalea Leaf Gall, Gypsy Moth caterpillars, Viburnum Beetle, Willow Beetle, Leaf miner on Chard and Aquilegia, Spittlebugs, White Pine Sawyers, early signs of Fire Blight on Malus are showing up.

Pioneer Valley Region (Amherst)

General Conditions: Conditions this past reporting period were very seasonable, even slightly on the cool side at times, with high temperatures ranging from the upper 60s to upper 70s and low temperatures ranging from the upper 30s to upper 50s. Scattered thunderstorms on 6/8 and 6/9 raced through the valley dropping between 0.7−0.9ʺ of rainfall. A late afternoon cell on 6/9 brought torrential rains that were falling at a rate of 4−5ʺ per hour. However, the front moved rapidly through the region and the heavy rains lasted only 10−15 minutes. That was enough to cause localized flooding in low-lying areas of Hampden County but no damage was reported. To date, June is well on its way to making up for the dearth of rain in May, with 2.25−2.75ʺ accrued so far. The effects of the soaking rain we received at the start of June are now clearly evident. Shrubs like butterfly bush and hydrangea have grown dramatically and lawn grass has been renewed in patches that were brown in late May.  Pests/Problems: The spruce spider mite continues its assault on a wide variety of conifers in the region. This pest was very problematic in 2014 and this year appears to be no different. Broad-spectrum insecticides can actually increase incidence by wiping out natural predators. Scout interior branches with a hand lens or magnifying glass to determine the severity of the infestation. Reports and samples of the Norway spruce gall midge continue to emerge. It is amazing and confounding how this pest suddenly became so widespread. Because of the dry conditions in May, most crabapples and apples have only minor symptoms of apple scab, frogeye leaf spot and cedar-apple rust. In fact, many leaf spot/blotch fungi are uncommon right now throughout the landscape. Once the cuticle is fully developed it is more difficult for foliar pathogens to invade, but many will now initiate infections with the recent rainfall providing the necessary moisture on the foliage surface. If the white prunicola scale is established on privet, cherry, lilac and euonymus now is time to treat the crawlers before they develop their waxy, protective covering. Continue to monitor and treat hemlock and true fir for the elongate hemlock scale. The staggered crawler emergence makes total control difficult, so persistence is necessary. Prune and discard flagging branches on hardwoods and conifers to keep stem cankering fungi from establishing and initiating new infections on adjacent branches. Mosquito populations seem to have declined, despite the recent rains. The above-average temperatures in May were blamed for the mass emergence of mosquitoes, as opposed to a more typical buildup over late spring and into early summer. Oriental bittersweet and Japanese knotweed, two of the most important invasive plants in the valley, are rapidly growing. Pruning and uprooting, while arduous, can control oriental bittersweet but herbicides and cultural methods are necessary to eradicate thickets of knotweed.

Berkshire Region (Great Barrington)

Current conditions: We seem to be in a hit or miss showery period and actual rainfall varied considerably in communities or parts of communities just a short distance from one another. Nevertheless, recent showers in South County have left soils moist but not muddy except for heavy soils. The past week has been cool with temperatures on Sunday (6/7) morning dropping into the mid-30s. I received one report of frost in Sheffield that morning which caused some damage to tomatoes and a few other tender crops. Interestingly, a neighboring garden had no frost. This could have been what meteorologists refer to as evaporation frost. This occurs when dry winds blow over a moist surface causing rapid evaporation of moisture and a lowering of temperature on that surface to create frost. Frost occurs on the leaf surfaces even though air temperature is above freezing. It’s not unlike the finding frost on a car windshield in the dewy morning of a cool but above freezing day in fall, winter, or spring. After a long droughty spell, the outlook for the next week or two is for occasional showers and much warmer temperatures. This should result in rapid growth of herbaceous plants, especially annuals and turfgrass.  Pests/Problems: Many of the same pesky critters of the past several weeks remain troublesome. The black-legged tick population continues at very high levels. You don’t have to walk in woods or tall weeds and grass to encounter ticks. Many people have picked up ticks by simply walking across their lawns. Other ongoing pest problems include: dog ticks, wasps, carpenter bees (abnormally high population this year), mosquitoes, eye gnats, snails, slugs, and leaf hoppers.  Some sooty mold is appearing on foliage of plants infested by aphids. This black mold grows in the sugary excretion, or honeydew, from the sap sucking aphids. Emergence holes can be seen on leaves of boxwood, indicating that the adult flies of Boxwood leaf miners have emerged. Often the pupal cases can be seen sticking out of the emergence holes. Nymphs of boxwood psyllid can still be seen on the cupped leaves at the tips of boxwood shoots. The nymphs should be developing into the adult stage very soon. Lily leaf beetle and rose slug are still in the larval stage and actively feeding on their hosts leaves. Gypsy moth caterpillars are feeding on oaks (bur oak was hosting a cadre of the caterpillars). Other active pests are: spruce spider mite, azalea sawfly, oak leaf scale (adults and eggs), imported willow leaf beetle (larvae), and cutworms. Adult black vine weevils have emerged and were caught in burlap traps placed beneath a sample of rhododendrons. Spittlebugs were found on pine and hemlock. A very colorful yellow and white striped caterpillar was found feeding on the foliage of witch hazel. The caterpillar was identified as belonging to the genus Pyreferra. Deb Swanson of Plymouth County believes the species to be Pyreferra hesperidago (Mustard sallow caterpillar) which she has seen there in past years.

Environmental Data

The following growing-degree-day (GDD) and precipitation data was collected for an approximately one week period, June 4 through June 10. Soil temperature and phenological indicators were observed on or about June 10. Total accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments for the 2015 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
(1-Week Gain)

GDD
(Total 2015 Accumulation)

Soil Temp
(°F at 4" depth)

Precipitation
(1-Week Gain in inches)

Cape Cod

71

441

62

0.07

Southeast

70

437

75

0.03

North Shore

59

455

75

0.03

East

64.5

526.5

70

0.05

Metro West

102

501

64

0.16

Central

87

556

60

1.48

Pioneer Valley

100

620

69

0.80

Berkshires

70

485

63

0.94

AVERAGE

78

503

67

0.45

n/a = information not available

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:

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.
Ligustrum spp. (Privet) * * begin * begin * begin begin
Catalpa speciosa (Northern Catalpa) * * * * begin * begin/full begin
Sambucus canadensis (American Elderberry) * begin/full begin/ full full * begin begin *
Syringa reticulata (Japanese Tree Lilac) * begin/full * begin begin begin begin begin
Cladrastis kentukea (Yellowwood) begin/full full full end full full full full/ end
Philadelphus spp. (Mockorange) begin full full full full full full begin
Kalmia latifolia (Mountain-laurel) begin/full begin/full begin/ full begin/full full begin/full full full
Hydrangea anomala petiolaris (Climbing Hydrangea) * full * full * full full begin/ full
Cornus sericea (Red Osier Dogwood) * * full/end * full/ end full full/end full
Robinia pseudoacacia (Black Locust) full end full/end * full/ end end end end
Cornus kousa (Kousa Dogwood) full full full full full full full full
Weigela florida (Old Fashioned Weigela) full full full end full full full full
Kolkwitzia amabilis (Beautybush) full full full full full full full full
Syringa meyeri (Meyer Lilac) full full/end full * full/ end full full/end full/ end
Deutzia spp. (Deutzia species) full full/end full full full/ end full full/end full
* = no activity to report/information not available
  • 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

Declining Norway spruce (Picea abies) infested with the Norway spruce gall midge (Piceacecis abietiperda) and spruce spider mite (Oligonychus ununguis) along with shoot tip blight caused by Phomopsis. Four trees, approximately 40-years-old, in a screen grouping with pine and true fir. Thinning foliage was noticed this spring. The bud scales at the base of this year’s shoots were removed to reveal newly developing galls from the gall midge. When the succulent bark tissue was scraped away with a scalpel, recently hatched larvae were present in their individual chambers. The spruce spider mite infestation was severe and Phomopsis is a now a regular pathogen on declining spruce. A multi-faceted complex that will be difficult to manage.

Colorado blue spruce (Picea pungens) suffering from spruce needle rust (Chrysomyxa weirii), needle cast caused by Stigmina (pictured below)and Rhizosphaera and an infestation of the spruce needleminer (Endothenia albolineana). Border screening of pure blue spruce, approximately 30 to 35-years-old. As the trees have grown together, the lower branches have declined due to lack of light and are now harboring numerous pests and pathogens. Aesthetically, the trees look terrible but still have live crown ratios of ~40-60% so they will survive for many years. Blue spruce should never be planted as a border screen for this reason.

Foliar blight caused by the anthracnose pathogen Apiognomonia errabunda on European beech (Fagus sylvatica). Tree is approximately 35-years-old and is well-maintained on a University campus. Very suddenly, half of the tree’s canopy browned and wilted. The anthracnose pathogen was abundant on the submitted sample and the recent rainfall likely initiated the disease outbreak. The tree’s canopy is partially shaded by surrounding trees, creating ideal conditions for the pathogen.

Needle tip blight caused by Phyllosticta thujae on arborvitae (Thuja plicata ‘Green Giant’). Shrubs are approximately 8ʹ tall and have been present at the site for only one year. An increasingly common and destructive pathogen of arborvitae, especially those suffering from stress.

Upper canopy dieback of red pine (Pinus resinosa) as a result of infections by Diplodia and Mycosphaerella. Tree is approximately 40 to 60-years-old and the symptoms were present in previous years. Needle browning and premature shedding and branch dieback in roughly 40% of the canopy.

Suspected winter injury and transplant shock on English oak (Quercus robur ‘Fastigata’). Two trees, 10ʺ in diameter at breast height, 40ʹ tall with 120ʺ rootballs were planted one year ago. Mechanical damage occurred at the base during installation and was noted shortly after planting. This spring, the trees did not leaf out and trunk cankers with sap flow and sloughing bark were observed. Phytophthora was not detected from the trunk cankers and there was no indication of pathogen or insect colonization. The damage appeared to be entirely abiotic.

Fruiting bodies of the needle cast pathogen Stigmina lautii rupturing through the stomata on needles of blue spruce (Picea pungens).       Interveinal chlorosis on pin oak (Quercus palustris), suspected to the result of iron deficiency.

For more detailed management information for woody plant diseases in the landscape, refer to UMass Extension's Professional Management Guide for Diseases of Trees and Shrubs.

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

Landscape Turf

Insects

White grubs

Deb Swanson, a recently retired Extension specialist who lives in southeastern Massachusetts, reported earlier this week that the oriental beetle adults were flying in her area. My guess is that we will start seeing adults throughout southern New England within the next few days, especially since the forecast is for temperatures in the 80s for the next week. Japanese beetle adults normally start to fly just a few days after the oriental beetles, so be watching for them as well.

Remember that the neonicotinoids (imidacloprid, chothianidin, or thiamethoxam) all should be applied when the adults are laying eggs. Normally it takes about a week after a beetle emerges before it is ready to mate and lay eggs, so your ideal timing will be coming soon. Also remember that the neonicotinoids can be toxic to honey bees and other pollinators, so be sure to use common sense:

  • Do not apply to surfaces where bees are foraging (e.g., white clover in bloom).
  • Be very careful on surfaces near flowering ornamental plants that are attractive to bees, because the product is systemic and may be taken into the flowering plants.
  • Remember that granular formulations generally are less directly toxic to pollinators than "sprayable" formulations.
  • Water the application in! Watering also greatly reduces exposure to pollinators.

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

 

Other Relevant News/Pest Alerts

June 15-21 is National Pollinator Week!  Refer to http://www.pollinator.org for additional information.

Additional Resources

To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list and follow us on Facebook and Twitter.

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