Landscape Message: April 14, 2017

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.

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

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Scouting Information by Region

Environmental Data

The following data was collected on or about April 12. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2017 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 (1-Week Gain)	Time/Date of Readings
	1-Week Gain	2017 Total	Sun	Shade
Cape Cod	12	28	62	59	0.52	4:00 PM 4/12
Southeast	19	38	60	51	2.25	4:00 PM 4/12
North Shore	28	56	51	48	0.61	9:30 AM 4/12
East	33	67	56	52	1.25	4:00 PM 4/12
Metro West	31	53.5	53	50	1.01	6:00 AM 4/12
Central	40	64	54	46	0.88	8:00 AM 4/12
Pioneer Valley	33	49	53	53	0.81	11:00 AM 4/12
Berkshires	21	33	55	52	0.56	10:00 AM 4/12
AVERAGE	27	49	56	51	0.99	-
n/a = information not available

Drought Conditions Update: Again, great progress with the recent precipitation, and great timing right at the start of the growing season.  Approximately 48% of Massachusetts is currently under official drought status. For the area under drought status, less than 1% of the Commonwealth is classified as 'Severe Drought'.  For more information see http://droughtmonitor.unl.edu/Home/StateDroughtMonitor.aspx?MA.

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.
Rhododendron 'P. J. M.'	*	*	*	*	*	*	Begin	*
Prunus serrulata (Japanese Flowering Cherry)	Begin	*	Begin	*	*	*	Begin	*
Forsythia x intermedia (Border Forsythia)	Full	Begin/Full	Begin/Full	Begin/Full	Begin	Begin/Full	Begin/Full	Begin
Rhododendron mucronulatum (Korean Rhododendron)	*	*	*	*	*	Begin	Begin	*
Magnolia stellata (Star Magnolia)	*	Begin	*	Begin	Begin	*	Begin	*
Pieris japonica (Japanese Pieris)	Full	Full	Begin/Full	Begin	Begin	Full	Full	Begin
Cornus mas (Corneliancherry Dogwood)	Full/End	Full	Full	Full	Full	Full	Full	Full
Acer rubrum (Red Maple)	Full	Full	Full	Full	Full	Full	Full	Full

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The temperature has averaged 48° F over the last week with a low of 38° F on both April 6 and April 8 and a high of 70° F on April 11. Approximately half an inch of rain fell on April 6. The last six days have been favorable for working outside with the last three days being primarily in the 60s. Lawns have really started to green up in the last week.

Pests/Problems: Winter moth hatch has just begun. Larry Dapsis, Entomologist with Cape Cod Cooperative Extension reported one larva found in sampled blueberry buds from Dennis on 4/11/17. I found a couple of larvae in apple buds on 4/12/17 in Falmouth. Winter cutworm, Noctua pronuba was found in turf in Orleans, many were found in the lawn. The following weeds are in bloom; Whitlow grass, Draba verna, Bittercress, Cardamine hirsuta, Chickweed, Stellaria media, Speedwell, Veronica spp., Fig buttercup, Ficaria verna, Henbit, Lamium spp.

Southeast Region (Hanson)

General Conditions: Like last year, the beginning of April, was cold and raw, but is now warming up. The Southeast area was fortunate to receive more rain, helping to alleviate some of the drought conditions. Hanson received 2.25 inches of much needed rain and soils are moist. The weather has turned more spring-like and the weather for April 11^th was warm and sunny with a temperature of 77 degrees. Plant development is slowly increasing and color is slowly creeping into the landscape. Unlike last year, Forsythia does not appear to be damaged from the rollercoaster freezing/warm weather, although other plants were affected. As reported last week, the flower buds of Spiraea ‘Ogon’ and Stachyurus praecox appeared damaged by the cold. Now, as the buds develop, it is easy to see that about 50-75% of the buds were killed. Other plants, like Pieris japonica, Japanese maple and butterflybush, also appear to have suffered some winter kill which will become more apparent as the season progresses. Depending on location, a few Magnolia stellata (Star magnolia) were observed beginning bloom, or in full bloom, however, most of the trees observed were not in bloom. Red maple, M. x loebneri 'Leonard Messel', Cercidiphyllum japonicum (Katsuratree), Salix sp.(pussy willow), Daphne mezereum (February Daphne), Cornus mas (Corneliancherry Dogwood), Corylopsis sp., Cornus officinalis, Pieris ‘Brouwer’s Beauty’, Lonicera fragrantissima (Winter honeysuckle), Pieris japonica (Japanese Pieris), Stachyurus praecox, Abeliophyllum distichum (White Forsythia), heaths and heathers Trillium, Helleborus niger, H. foetidus, H. x hybridus, Corydalis solida, Omphalodes verna, daffodils, Chionodoxa luciliae, Sanguinaria canadensis (Bloodroot), Crocus, Scilla sibirica and Pulmonaria sp. are in full bloom. Pieris floribunda, Vinca minor, Petasites japonicus, Dicentra cucullaria (Dutchman’s breeches), Anemone blanda, and Brunnera macrophylla have started bloom. Weeds like dandelions, bittercress and Ranunculus ficaria have also started to bloom. Lawns are starting to green up and although soils are moist, they are workable and landscape cleanups have begun in earnest. Many landscapes remain littered with fallen branches, etc, due to recent high winds. The site in Hanson is reporting 231 GDD (Growing Degree Days) at base 40.

Pests/Problems: Winter moth eggs just started to hatch in Hanson (on the south side of the tree being monitored for hatch) on Friday April 14, at 41 GDD, base 50. The remaining winter moth eggs on the north, east and west side of the tree, have not yet hatched and remain orange. Winter moth eggs will turn blue as the larvae mature within the egg, just prior to hatch. With the warm weather forecast, we should be seeing more eggs hatch as the week progresses. However, it is important for clients with apple trees, blueberry bushes or other fruit affected by winter moth, to be preemptive and apply dormant oil and/or an insecticide application, according to label instructions, to those apple trees, blueberry bushes, etc., as weather permits. Once the caterpillars are inside the apple or blueberry buds, they eat the reproductive parts and the result is that there is nothing to pollinate and no fruit will be produced.  (Please see Tawny Simisky's report in the Insect Section of the Landscape Report) Hanson is at  254 GDD, base 40.

Monitor hemlocks for the white cottony egg masses of Hemlock Wooly Adelgid (HWA). If found, manage as needed.

Brown marmorated stink bug was found in Hanson. For more information on this introduced species, go to: http://www.massnrc.org/pests/pestFAQsheets/brownmarmoratedstinkbug.html

Monitor for Red Lily Leaf Beetles which, with the recent warm weather, should be making their appearance on newly emerging lilies. These bright red beetles are easy to see. Handpick and destroy and/or manage early with a registered insecticide to prevent damage to lilies. Continue to be vigilant and take precautions against deer ticks and conduct deer tick checks frequently and use a repellent when working outdoors in tick territory. Bumblebees, carpenter bees, and solitary bees are active, as are wasps.

Cabbage butterfly and Mourning Cloak butterfly were observed this past week.

Continue to transplant, or plant, woody plants when the ground is workable. Now is also a good time to transplant late-summer or fall blooming perennials. Remember to water at the time of planting, as well as after planting, even if rain is forecast. Rabbits are active and feeding on tulips, Scilla etc. Deer continue to browse and damage to the crowns of hosta, Epimedium, etc. by voles continues to be seen.

North Shore Region (Beverly)

General Conditions: The weather this reporting period was variable. The start of the reporting period in the middle of last week was mild with rain showers. Approximately 0.61 inches of rain was received at Long Hill. The last two days temperatures were unseasonably warm reaching up to the mid 70s and low 80s. During this reporting period we accumulated 28 degree degrees at Long Hill. Woody plants seen in bloom include: Red maple (Acer rubrum), Cornelian Cherry Dogwood (Cornus mas), Japanese flowering cherry (Prunus serrulata), Anise Magnolia (Magnolia salicifolia), Golden Times Forsythia (Forsythia giraldiana), Winter honeysuckle (Lonicera x purpusii), February Daphne (Daphne mezereum), Winterthur winterhazel (Corylopsis winterthur), Weeping Forsythia (Forsythia suspensa), and Leatherwood (Dirca palustris). Non woody plants seen in bloom include: Siberian squill (Scilla siberica) and Puschkinia (Puschkinia libanotica), Glory of the Snow (Chionodoxa), White Tommy crocus (Crocus tommasinianus), Daffodil (Narcissus sp.).

Pests/Problems: Fungal leaf spot of mountain laurel was observed on some shrubs in the landscape. Cultural practices that promote plant vigor such as proper watering, fertilizing, properly timed pruning and raking and removing fallen leaves in the fall can help in the management of the disease. Yellow buttercup weed (Ranunculus ficaria) is blooming on lawns. With the rise in temperatures ticks are very active. Take precautions when working outdoors, like applying repellents such as DEET.

East Region (Boston)

General Conditions: The weather continued to be cool, grey, and rainy this week, an all-day soaker dropped 1.25 inches of rain on the 6^th. The sun finally returned on April 8^th before temperatures warmed to 67° F on the 9^th, 78° F on the 10^th and kept climbing to 86° F on the 11^th – setting a new record. The warm temperatures were welcomed as we had last reached above 60° F on March 1^st. It had been a month since we last gained GDDs and we gained 33 GDDs over this warm period. Many plants are beginning to come into bloom: Cercidiphyllum japonicum (katsura), Dirca palustris (eastern leatherwood), Lonicera standishii (Standish honeysuckle), Magnolia salicifolia (willow-leaved magnolia), Magnolia stellata cultivars ‘Rosea’ and ‘Waterlily’ (cultivar of star magnolia), and many Prunus sp. including P. apetala (petalless cherry), P. cerasifera (Myrobalan plum), P. cyclamina (Cyclamen cherry), P. nipponica (Japanese alpine cherry), P. sargentii (Sargent cherry), and P. x yedoensis ‘Shidare Yoshino’ (cultivar of Yoshino cherry). Spring bulbs are in full bloom, with Chionodoxa forbesii (Forbes' glory-of-the-snow), Crocus sp. (crocus), Puschkinia scilloides (striped squill), and Scilla siberica (Siberian squill) putting on a great show! Jeffersonia diphylla (twinleaf), the native spring wildflower named after Thomas Jefferson, is in full bloom.

Pests/Problems: The warm weather over the last 3 days has led to winter moth (Operophtera brumata) hatch, although numbers are well below 2016 levels. Ficaria verna (lesser celandine) is in full bloom, dominating the herbaceous layer. Alliaria petiolata (garlic mustard) rosettes are gaining in size while the seedlings have germinated from pre-existing seed banks in mulched beds and exposed soils.

Metro West (Acton)

General Conditions: The first round of April showers came and went and left us with some flowers, erosion, saturated soils, warm temperatures, swollen buds, and green lawns. Average rainfall total for the month of April is 4.16” and I have recorded 3.69” for the first eleven days of this month so far. I hate to jinx it, but we may meet the monthly average total with more than half of the month remaining to record more precipitation! Since, the last report, one week ago, there has been a gain of 31 growing degree-days. We picked up 19 GDD on the 11^th with a high of 87° and a low of 51° and even more on the 2 days prior. In some stage of bloom at this time are: Acer rubrum (Red Maple), Cornus mas (Cornelian Cherry Dogwood), C. officinalis (Japanese Cornelian Cherry), Forsythia x intermedia (Border Forsythia), Magnolia stellata (Star Magnolia), and Pieris japonica (Japanese Pieris). The following bulbs and herbaceous plants in bloom are: Adonis amurensis (Adonis), Chionodoxa spp. (Glory of the Snow), Crocus spp. (Crocus), Galanthus nivalis (Snowdrop), Helleborus niger (Christmas Rose), Petasites japonicus (Japanese Butterbur), Puschkinia libanotica (Striped Squill), Scilla siberica (Siberian Squill), and Symplocarpus foetidus (Skunk Cabbage).

Pests/Problems: Ticks are active, as well as rabbits. Draba verna (Spring Whitlow Grass) and Lamium purpureum (Purple Deadnettle), both winter annual weeds are in bloom.

Allium vineale (Wild Garlic) has exploded with the rain and heat and its leaves seemed to appear overnight! Wide spread Pinus strobus (White Pine) are badly discolored for a second year in a row due to a number of factors including scales.

Central Region (Boylston)

General Conditions: The reporting period started out cold and rainy with temperatures in the 30’s by night and 40’s by day. As the week wore on the temperatures gradually rose to a record breaking 87 degrees on Tuesday, April 11th. These record warm temperatures brought early blooming minor bulbs, shrubs and perennials to the precipice of full bloom, seemingly overnight. Glory of the Snow (Chionodoxa forbesii) and cultivars of Siberian Squill (Scilla siberica), February Daphne (D. mezereum), many Willows (Salix sp), Harry Lauder’s Walking Stick (Corylus avellana ‘Contorta’), Pieris ‘Brouwer’s Beauty’ and Cornelian Cherry (Cornus mas and C. officinalis) are in full bloom. Winter Aconite (Eranthis hyemalis) has finished blooming, and few buds remain on White Forsythia (Abeliophyllum distichum) - many were damaged by cold temperatures in March. Among the plants beginning to show color are Magnolia salicifolia, and early Daffodils (Narcissus cv.), Winterhazel (Corylopsis spicata and C. pauciflora), Mountain Andromeda (Pieris floribunda), Bloodroot (Sanguinaria canadensis), Fragrant Lonicera (L. x purpusii), Fumewort (Corydalis solida), and Rhododendron mucronulatum ‘Cornell Pink’. Leaves are beginning to emerge on Crabapple (Malus cvs), Korean Abelia (A. mosanensis) and Seven Son Flower (Heptacodium miconioides). Spring Peepers and Wood Frogs are happily sounding off in vernal pools throughout the region.

Pests/Problems: Voles, rabbits, chipmunks, squirrels and deer are all active and eyeing the tulips for their next meal. Woodchucks are out and active. Taste and odor repellents are helpful with deer and rabbits, but the voles, squirrels and chipmunks are undaunted. Ticks are plentiful. Signs of black bear have been seen in and around the location of birdfeeders. Birdfeeders should be on bear-proof poles or removed for the season. Soils are still quite soggy so foot traffic and activities on turf should be limited until the soils dries out.

Pioneer Valley Region (Amherst)

General Conditions: This past reporting period can be best described as “the payoff”. After months of bleak winter weather, spring arrived in force in the Pioneer Valley. The reporting period started off modestly, with cloudy skies and cool temperatures in the upper 40s and low 50s as additional rainfall accumulated, piling on even more moisture to already saturated soils. But since the heavy downpour (with plentiful thunder and lightning) on 4/6 and 4/7, conditions have been mostly dry, allowing soils to drain. On Sunday, 4/9 temperatures began their ascent; first soaring into the upper 60s, followed by middle 70s on 4/10 until finally peaking at summer-like highs in the upper 80s on 4/11. High temperature records for 4/11 were shattered across the region and with no canopy cover from deciduous trees, the heat was too early and too much for many. Conditions have since moderated at the time of writing, with more seasonable highs in the 60s forecasted for the weekend. Soil temperatures increased an astounding 10°F in just one week, leading to a rapid greening of turfgrasses and growth of spring flowers and groundcover like crocuses, daffodils and vinca. Now that soil temperatures are above 50° F, new root growth will be stimulated for many trees and shrubs. With moist soils and mild temperatures ahead, this is a great time for planting trees and shrubs. Crabapple, serviceberry, katsura, viburnum, yew and mountain laurel were all observed flushing new growth and swelling buds were observed on numerous other trees and shrubs on the UMass campus. Nighttime temperatures are expected to be more seasonal in the upcoming forecast, returning to the upper 30s to 40s. The cold nights ahead will likely slow leaf development and bud break until low temperatures climb back towards 50°F. As is spring in the valley, winds have been persistent and strong at times, even drying exposed surface soils with the heat of 4/11. Red flag warnings were in place for hardwood-dominated forests with southern exposure, where fine fuels could ignite (e.g. the Holyoke side of Mount Tom). A flood watch remained in effect for low lying areas along the Connecticut River on 4/11 and 4/12, especially in Northampton near the oxbow. Draining of lower order streams and rivers into the Connecticut has it brimming near “action stage” according to the River Forecast Center. However, it appears that flooding will be restricted to the lowest lying areas where spring overflow is common.

Pests/Problems: Winter injury is rampant on rhododendron, mountain laurel, azalea, holly, inkberry, hemlock and various other evergreen trees and shrubs. For many of these plants, the injury is not severe and blighted plant parts can be pruned and discarded. For others, the damage is more serious and may contribute to an irreversible decline. Last year’s drought may have inhibited cold acclimation during the autumn and early weeks of winter, leading to increased levels of cold damage over previous years. Symptoms are highly variable, but blighted leaf margins predominate. The necrotic leaf sections can serve as an infection site for opportunistic pathogens that can cause further injury. Examine the base of evergreen and deciduous shrubs for evidence of bark chewing from meadow voles. Mature plants can often tolerate low to moderate levels of damage with no noticeable symptoms in the canopy, but young plants may experience canopy dieback if a significant percentage (>50%) of the basal stems have been stripped of bark. White pine problems continue, with browning needle tips and premature needle shedding in both forest and landscape settings. Right now, it’s too early to assess the extent of any additional damage, as candles are just starting to elongate. Symptom development on last year’s needles will become more apparent as we progress through the month of May, so all we can do is wait at this point. The warm temperatures likely initiated fruiting body development for certain anthracnose fungi and foliar blight pathogens. Thankfully, there are no leaves yet to infect for many landscape trees and shrubs. Apple and crabapple are flushing new growth and apple scab infections will likely take place over the next several weeks. Continue to scout for and prune dead stems and branches from trees and shrubs. As buds swell and break, it is becoming easier to identify dead plant parts. Lacebug injury on Andromeda, azalea and rhododendron is widespread and severe in some cases.

Berkshire Region (Great Barrington)

General Conditions: It was an up and down week with below normal temperatures From April 5th – 8^th, culminating with a dusting of snow on the morning of the 8^th. As one went north from Great Barrington, the amount of snowfall was greater, yet no more than a light covering, i.e. less than an inch. After that chilly and damp spell, temperatures quickly shot up to well above normal: a high temperature of 78° F on Monday, April 10^th and a record high of 83° F on the 11^th. Water levels in rivers and streams remains high but little flooding has been reported. Soil moisture levels are high though the high temperatures and sunny conditions over the three day period of April 9, 10, and 11 did result in some drying; enough drying to make soils workable on sites with good drainage. Despite the dramatic warmth, there was no equally dramatic increase in plant growth, though more spring flowering bulbs could be seen to be in bloom.

Pests/Problems: With the low accumulation of GDDs, there has been no sign of insect pest emergence. The only troubling insects are of the nuisance types which have occupied many homes this past winter. Most common of these is Western conifer seed bug, boxelder bug, cluster flies, and multi-colored Asian lady beetle. On the other hand, deer ticks have been numerous and reports of people finding the ticks attached to their clothing or being bitten by the ticks are frequent. The most common problem of plant material in gardens and landscapes concerns browsing by deer, rabbits, and voles. A visible symptom of vole activity can be seen in the form of meandering trails across lawns where the voles have foraged on grass blades and roots. Where such trails exist, one should inspect adjacent thin-barked and immature trees, and shrubs for evidence of chewed bark, another bit of damage caused by the gnawing habits of voles.Though insect pests are not yet active, this is a good time to inspect trees and shrubs for egg masses of pest insects, e.g. Eastern tent caterpillar and gypsy moth. Also, inspect the underside of viburnum twigs – last season’s growth – for a row of scars (caps) left by the egg efforts of the viburnum leaf beetle. Blisters on leaves of boxwood indicate the presence of larvae of boxwood leaf miner.

Regional Scouting Credits

• CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, 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 pests and pathogens of interest seen in the UMass Extension Plant Diagnostic Lab:

Stigmina needle cast, caused by Stigmina lautii, of Serbian spruce (Picea omorika). Tree is somewhere between five and ten-years-old and has been present at the site for only two years. Symptoms (Fig. 1) include blackened needle tips, yellowing needles, premature shedding and death of lower canopy branches. The planting site has direct sun and rocky soils but the tree receives drip irrigation. Poor establishment at the site is the most likely predisposing stress. Stigmina is often found with the better-known Rhizosphaera, but the latter was not present in this case.

Lophodermium needle cast, caused by Lophodermium juniperinum, on creeping juniper (Juniperus sp.). Numerous plants, established in a large rectangle-shaped bed adjacent to a driveway, that are approximately 10-years-old. Interestingly, the plants closest to the drive appear healthy, while plants furthest are symptomatic. Browning needles and outright death were not observed in 2016. There are many species in genus Lophodermium, including several that attack pine. On ground cover junipers, the pathogen can be problematic at times because of the dense canopy and overlapping branches that create ideal conditions for spore dispersal and spread. There was also a minor infestation of the juniper scale, but it likely played little, if any, role in the observed decline. The beds do receive drip irrigation.

Poor vigor and edema due to overwatering on holly (Ilex opaca) and mountain laurel (Kalmia latifolia). Symptoms of edema appeared as brown-colored, raised blisters scattered across the underside of the foliage (see Fig. 2). Several shrubs are affected, ranging in age from eight to ten-years-old, planted three years ago. The plants are on a slope in full sun but soils are a mix of clay and loam. Drip irrigation is providing too much water to the plants and they have thin canopies with off-color foliage.

Phomopsis cankering of knockout rose (Rosa ‘Radrazz’ KNOCKOUT). Plant is approximately 12-years-old and symptoms (stem cankers and lack of vigor) have been present in previous years but worsened 2016. The plant is one of 17 planted along a fence next to a parking lot. There is a small strip of grass between the beds and the parking lot. Phomopsis is a generalist, but can be found attacking rose canes. Prune sites provide easy access and large volumes of spores that are produced are blown and splashed to nearby canes. The fungus does not survive in the soil, so pruning and removal of diseased canes can control the pathogen

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:

• Winter Moth: Operophtera brumata. The eggs of this insect, laid by the females who emerged in November of 2016 and were active through the winter months (mainly November through December when temperatures are above freezing) are currently present in the landscape and hidden in cracks and crevices of bark or beneath lichen on host plants such as oak, maple, apple, blueberry, crabapple, etc. Eggs are tiny and green when first laid, but quickly turn a red-orange color soon after. As the egg develops, it will turn blue in color, shortly prior to egg hatch. For more information about the life cycle and management of winter moth, please visit this newly updated (March, 2017) fact sheet: Winter Moth Identification and Management (https://ag.umass.edu/landscape/fact-sheets/winter-moth-identification-management).

According to reports, winter moth eggs have begun to hatch in Franklin, MA (Heather Faubert, University of Rhode Island) as of 4/6/2017. Heather Faubert also reports that winter moth eggs have (as of 4/7/2017) begun to hatch in additional locations in Rhode Island, including but not limited to sites being monitored in North Scituate, Kingston, and Little Compton. Heather mentions that the activity at the site in Little Compton is surprising due to its proximity to the ocean as such sites typically have later winter moth egg hatch due to the cooler spring temperatures experienced in coastal areas. As for coastal areas in Massachusetts, a report came from Larry Dapsis with Cape Cod Cooperative Extension on 4/11/2017 that he observed a single winter moth larva after checking 100 buds at a site in Dennis, MA. This may indicate the very beginning of winter moth egg hatch at this location, however this process takes time. Winter moth egg hatch on Cape Cod is typically delayed due to cooler temperatures and occurs after egg hatch begins in more inland locations. Sites he monitors in West Barnstable and Falmouth (as of 4/11/17) have not yet yielded any winter moth larvae, however Russell Norton with Cape Cod Cooperative Extension reports finding a couple of larvae in apple buds as of 4/12/17 in Falmouth. Please see the Cape Cod Region Report above. As of moments ago on 4/14/17, winter moth egg hatch was observed on the south facing side of a tree being monitored at a site in Hanson, MA. Winter moth eggs on the other sides of the same tree are still orange in color. See the Southeast Region Report above for more information. Winter moth eggs are still orange in color at the sites being monitored by the Elkinton Lab. Winter moth egg hatch is just beginning in the aforementioned parts of Massachusetts. We will continue to monitor egg development and will report any additional development reported by scouts in the next Landscape Message due April 21^st. You may also visit the UMass Landscape, Nursery, and Urban Forestry Facebook page @UMassExtLandscape for announcements regarding winter moth activity.

Blueberry and apple growers looking to manage winter moth caterpillars early before damage to the buds can occur may consider an application of dormant oil just prior to egg hatch, when temperatures are above 40° F for at least 48 hours following application, which can help suffocate overwintering winter moth eggs if good coverage is achieved. Observe all precautions on the label regarding phytotoxicity and the environmental conditions required for increased effectiveness of the product. Once egg hatch occurs, before the tiny winter moth caterpillars wriggle their way into the expanding blueberry or apple buds (where they will be protected from insecticide applications until the buds open fully), a follow-up application of a product containing the active ingredient spinosad (which is effective by contact) can aid in protecting these crops.

For individuals managing winter moth in ornamental plants, depending on the active ingredient being used, waiting until host plant leaves open completely may be important for management, particularly if Bacillus thuringiensis Kurstaki (Btk) is the active ingredient of choice. Btk must be ingested by actively feeding, young caterpillars to be effective. Applying Btk to closed buds for winter moth management will not have the desired effect. Spinosad is also effective through contact on winter moth (including older caterpillars) once ornamental plant leaves have fully expanded, however it should not be applied to flowering plants as it is toxic to pollinators until it has dried (which can take 1-3 hours depending upon local environmental conditions). The Elkinton Lab has reported that the number of pupating winter moth in 2016 (at their study sites) was much lower than what has been observed in previous years. Reports from Hanson, MA indicate fewer winter moth eggs are present on monitored trees than in previous years. Hopefully this will translate into fewer caterpillars at least for some areas in Massachusetts this year, however one should not expect them (or the damage they cause) to completely disappear in 2017.

Winter moth is a non-native insect that was identified in Massachusetts for the first time in 2003 following persistent reports of defoliation in eastern areas of the state such as Cape Anne and on the North Shore near Cohasset, Hingham, and Rockland on the South Shore in the late 1990’s. For more detailed information about the history of this insect pest in North America and Massachusetts, please visit the newly updated (March, 2017) fact sheet: Winter Moth in Massachusetts: History and Biological Control (https://ag.umass.edu/landscape/fact-sheets/winter-moth-in-massachusetts-history-biological-control).

This fact sheet also includes updates regarding the progress of the work of Dr. Joseph Elkinton’s laboratory group at the University of Massachusetts and their efforts towards the biological control of winter moth using Cyzenis albicans, a tachinid fly. The fly parasitizes the caterpillars of winter moth specifically. In other areas, such as Nova Scotia where winter moth was also problematic, this fly used for biological control has been successful in reducing winter moth to a non-pest. C. albicans has been released across 41 sites in Massachusetts and has been established in at least 17 of those sites as evidenced through the recovery of flies in winter moth in subsequent years. In one site in Wellesley, these flies have been observed to be spreading from the initial release location and their populations have increased alongside an observed decrease in the winter moth population there. For more information, please visit the above mentioned fact sheet.

• Balsam Twig Aphid: Mindarus abietinus is active between 30-120 GDD’s, base 50°F. Inspect the needles of fir for “stem mothers” that will soon be reproducing. Young aphid feeding will lead to distorted foliage. Excessive amounts of honeydew are produced and cause needles to stick together. Monitor for the presence of reproducing females and treat with an oil application as weather permits.

• Cooley Spruce Gall Adelgid: Adelges cooleyi is active between 20-91 GDD’s, base 50°F. This insect can be found in the crevices of bark on terminal twigs and bases of buds of blue spruce, Norway spruce, and Douglas fir. Control overwintering nymphs prior to gall formation on spruce (roughly 22-81 GDD). Oil applications on Douglas fir should be made before bud break to avoid phytotoxicity (roughly 120-190 GDD). Do not plant spruce and Douglas fir close together. Do not fertilize either host (spruce or Douglas fir) if it is infested with this insect.

• Eastern Tent Caterpillar: Malacosoma americanum eggs will begin to hatch and caterpillars will feed across the state between 50-400 GDD’s, base 50°F. Egg masses of Malacosoma americanum vary from those of Malacosoma disstria, the forest tent caterpillar, as they have a rounded edge whereas M. disstria egg masses have square edges. Scout for and remove these egg masses prior to hatch on susceptible hosts such as cherry and crabapple. Other host plants impacted by this native insect can include apple, ash, birch, willow, maple, oak, poplar, and witch-hazel. Once the eggs have hatched, tiny caterpillars will begin to create small webs or tents in the crotches of branches. These tiny tents can be removed and destroyed, along with the tiny caterpillars within; before they become large and significant defoliation takes place.

• Forest Tent Caterpillar: Malacosoma disstria egg hatch will occur between 192-400 GDD’s, base 50°F. Scout for and prune out or otherwise remove any reachable forest tent caterpillar egg masses, which can hold 100’s of eggs, on susceptible hosts such as oak, birch, ash, maple, elm, poplar, and basswood at this time. Once these egg masses hatch, these native caterpillars can defoliate their host plants.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. This beetle feeds exclusively on many different species of viburnum. This insect is now overwintering in the twigs of the host plant as eggs, which will hatch soon after bud break. Now is the time to inspect susceptible plants (including but not limited to viburnum such as V. dentatum, V. nudum, V. opulus, V. propinquum, and V. rafinesquianum) for over-wintering eggs on stems toward branch tips. Inspect branches for egg laying sites created by female viburnum leaf beetles last season. These will appear as small holes approximately 1 mm. in diameter that have been capped with a lid made of chewed bark and excrement, which may appear raised above the surface of the twig. Removal and destruction of infested stems, if small in number, can help reduce populations of this insect pest. If management this way is not possible, larvae may be treated with a product containing spinosad once they appear soon after bud break. Some viburnum have been observed to have varying levels of resistance to this insect, including but not limited to V. bodnantense, V. carlesii, V. davidii, V. plicatum, V. rhytidophyllum, V. setigerum, and V. sieboldii. More information about viburnum leaf beetle may be found at http://www.hort.cornell.edu/vlb/.

• Gypsy Moth: Lymantria dispar egg masses laid by female moths in 2016 can be seen at this time. This is the stage of the insect that overwinters. Egg masses are “fuzzy” or hairy and brownish-tan in color. Each egg mass can hold up to 500-1000 eggs. These masses may be found on host plant trunks and branches such as oak (favored), maple, birch, poplar, and many others, but are also laid on inanimate objects including the surfaces of homes, outdoor furniture, camping equipment, firewood piles, etc. This may make the accidental movement of gypsy moth egg masses possible.

Egg hatch for this insect is not yet upon us, and occurs after winter moth egg hatch. (Note: winter moth and gypsy moth share some common host plants. Therefore, where populations of these two insects overlap in Massachusetts, the same tree may be defoliated by winter moth and then again by gypsy moth following in the same season.) Gypsy moth egg hatch typically occurs between 90-100 growing degree days, using a base of 50°F, average temperatures, and a March 1^st start date. This is usually around the first week in May in Massachusetts, but variations in temperature may lead to early egg hatch in the last week in April. This can also coincide with serviceberry (Amelanchier) bloom. After egg hatch occurs, groups of tiny gypsy moth caterpillars may remain on their egg mass just before crawling to the canopy of their host plant, where they can disperse using a technique known as “ballooning”. Ballooning occurs when very young caterpillars spin a silken thread and catch the wind to blow onto a new host plant once the thread breaks. This method of dispersal can lead to host plants becoming defoliated that previously did not have egg masses directly on them, however egg masses may be present on nearby oaks, for example, and provide a local population of caterpillars.

Patchy areas across mostly central and eastern Massachusetts experienced elevated populations of gypsy moth and significant amounts of defoliation in 2016 (see the Insects section of the archived 2016 Landscape Messages between April 29 and July 29). The Massachusetts Department of Conservation and Recreation aerially mapped approximately 350,000 acres of defoliation across Massachusetts last year, attributed to gypsy moth. State officials warn the public about another year of defoliation from gypsy moth as predicted for 2017: http://www.mass.gov/eea/agencies/dcr/pr-2017/another-year-of-defoliation-from-gypsy-moth-in-2017.html. That web page also links to a map of the 2016 defoliation from gypsy moth, which may provide a reference regarding areas that may be impacted by this insect again in 2017. To prepare for this insect, now (and before the last week in April) is a great time to scout the landscape and count the number of gypsy moth egg masses present not only on valuable landscape specimens that are hosts for this insect, but on nearby forested hosts such as oak which might provide sources of ballooning caterpillars. Egg mass counts can help us make decisions regarding whether or not to manage for this insect. Some individuals also use this opportunity to scrape egg masses into a container of soapy water, although this is time consuming and some egg masses will be missed.

We can hope for elevated rainfall in the months of May and June, which helps facilitate the successful infection of younger gypsy moth caterpillars with the insect-killing fungus Entomophaga maimaiga. This fungus is currently overwintering in the soil litter in tough, protected asexual resting spores, which can survive in this state for years. Having lacked much precipitation most recently during the springs of 2015 and 2016, it is thought that our current expanding populations of gypsy moth are at least in part a result of a lack of infection in the caterpillar population by this fungus. Hopefully Massachusetts will see more normal rainfall amounts this season. Only time will tell.

We can also hope areas in Massachusetts that do not have large numbers of gypsy moth egg masses present at this time and did not experience much gypsy moth defoliation last year (areas such as most of Berkshire County) will be mostly spared in 2017 in comparison to those areas who suffered last year in central and eastern Massachusetts. At this time, monitoring susceptible hosts for gypsy moth egg masses and educating and reminding ourselves about this invasive insect that has a long history in the state is the best way to plan for management this season. For more information about gypsy moth, please visit: http://ag.umass.edu/landscape/fact-sheets/gypsy-moth and return to the Landscape Message for timely updates about this pest and others throughout the season.

• Chilli Thrips: *A non-native insect has been confirmed in Massachusetts for the first time.* The non-native, exotic chilli thrips (Scirtothrips dorsalis) has been recently confirmed from two samples of damaged Hydrangea spp. foliage from two residential landscapes located in Barnstable County, MA submitted to the UMass Plant Diagnostics Laboratory. At this time, this pest has not been confirmed in nurseries or greenhouses in Massachusetts or on any other host plants. Due to the limited number of samples, the significance of chilli thrips in Massachusetts is not yet known. This species of thrips is a significant global pest of economically important ornamental, vegetable, and fruit crops in southern and eastern Asia, Oceania, and parts of Africa. It was first determined to be established in the United States in 2005 in Florida, although previous interceptions of this pest were detected. It is reportedly a pest of over 100 host plants belonging to over 40 plant families, including, but not limited to, pepper, strawberry, blueberry, cotton, rose, peanut, Japanese privet, Rhododendron spp., Viburnum spp., eggplant, grapes, melon, tobacco, and tomato. For more information, please visit this Chilli Thrips Fact Sheet (https://ag.umass.edu/landscape/fact-sheets/chilli-thrips) available on the UMass Extension Landscape, Nursery, and Urban Forestry Program web page.

• Asian Longhorned Beetle, Anoplophora glabripennis, ALB: Look for 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. These particular signs of damage from the beetle may be more visible at this time of year, when host trees such as maples are leafless. Be advised that other, native insects may create perfectly round exit holes or sawdust-like frass, which can be confused with signs of ALB activity.

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 seen damage caused by this insect, such as exit holes or egg sites, 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. Adult insects of this species will not be present at this time of year.

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.

• 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). Adult insects of this species will not be present at this time of year. Signs of an EAB infested tree may include (at this time) D-shaped exit holes in the bark (from adult emergence in previous years), “blonding” or lighter coloration of the ash bark from woodpecker feeding (chipping away of the bark as they search for larvae beneath), and serpentine galleries visible through splits in the bark, from larval feeding beneath. Positive identification of an EAB-infested tree may not be possible with these signs individually on their own.

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. If you believe you have located EAB-infested ash trees, particularly in an area of Massachusetts not identified on the map provided, please follow the instructions below.

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: Forsythia x intermedia

Forsythia x intermedia is a sign that spring has arrived. Border forsythia is a large, upright, arching shrub that can reach 8-10’ tall and 10-12’ wide. Flowers are 4-petaled, yellow, 1-1.5” long and wide and bloom before leaf emergence in April. Leaves are 3-5” long ovate, medium green and have sharply serrated margins. Plants do not have good fall color. Flower buds are formed on the previous year’s wood so plants should be pruned after flowering in the spring. Regular pruning helps to maintain good form. Options include pruning out old wood every year after flowering or a hard prune of all canes every 3-4 years. Forsythia is best used in mass plantings, shrub borders, or on banks or slopes. The early spring flowers are the main ornamental interest. Flowering can be negatively impacted by late freeze events. Plants are best grown in full sun to part shade with best flowering in full sun. They are tolerant of poor soils and can be drought tolerant once established. Cultivars can offer smaller forms ('Gold Tide'), light yellow flowers ('Lynwood'), variegated leaves, or bushier forms. Although often called a “one-season wonder”, the golden yellow blooms are a welcome sight after a long New England winter.

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

Landscape Turf

Management Practices

Evolving nutrient management regulations in Massachusetts and beyond have brought increased focus on turf fertilizer programming and fertilizer applications. A primary goal for any turf fertilizer program is to time maximum nutrient availability to coincide with periods of peak turfgrass growth. In the spring, the window of ideal growing conditions is relatively short – sandwiched between the recession of winter and subsequent recovery, and the arrival of hotter, drier conditions that bring summer-related stress and associated growth and management challenges.

Here and now, Marathon Monday is just days away in Massachusetts, The Masters just wrapped, the fertilizer ads are heavy on the radio and TV, and we're into our second round of great spring weather (the first arrived in... February?). These influences make the appropriate timing for that first spring fertilizer application a popular topic of conversation.

After the average New England winter, time is one thing that a turf system needs after the snow melts and the soil begins to thaw. From a nutrient perspective, water must be free and in liquid form for nutrients to be mobile in soil and available for plant uptake. Fertilizer applied too early, when soil has not thawed completely and/or stand density has not recovered sufficiently from winter shoot dieback, has a much greater potential of being carried out of and away from the turf system with runoff.

Roots also need to be active and viable for nutrient absorption to occur. Harsh winter conditions cause roots to die back, therefore a degree of root system recovery should take place prior to fertilizer application. The physical passage of mineral nutrients from the soil into root tissue, furthermore, is a largely active process for which energy is required. This means that photosynthesis and other biological functions must be up and running to adequately supply this energy. Nutrients in the soil solution that are not taken up promptly may be subject to loss through leaching and lateral movement.

The simple solution to promote robust plant uptake and minimize loss is to wait to fertilize in the spring until growth is solidly established, with the minimum threshold being the point of approximately 50% green-up. Contrary to what some believe, fertilizing early will not stimulate earlier growth; the onset and acceleration of both shoot and root growth are largely temperature dependent. Also, the calendar is never really useful in this regard, because of often significant year-to-year variation (at this time in 2012, Boston had 110 growing degree days; this year as of this writing, 67). Further variation can be introduced by many factors including geography, ambient temperatures, soil temperatures, soil moisture levels, exposure, etc. While sunny sites on the Cape may be about ready, for example, sheltered locations in the Berkshires may need significantly more time. The progression of aerial shoot growth and green color (see photo above right) are built-in signals that account for all of the above factors.

It is important to remember and keep in perspective that the aim is to maximize plant uptake while simultaneously minimizing nutrient loss from the system. Nutrients lost to the environment, most notably nitrogen and phosphorus, have a much greater potential of reaching and accumulating in ground and surface waters and negatively impacting the environment. In addition, nutrient loss is wasteful of limited time, labor, fertilizer, and financial resources. Nutrients that leave the system will not support the desired response in the turf, and may lead to performance and management problems and increase the need for future inputs.

For a final, related tip, don't let combination products be the boss when it comes to application timing. While the intent of fertilizer/pest control combination products is to 'kill two birds with one stone' for the sake of efficiency and convenience (fertilizer and pre-emergence herbicide, for example), the timing for one objective may have to be compromised in support of getting the correct timing for the other objective. If the compromise will be significant, opt for separate fertilizer and pest control applications for greater accuracy and control.

Report by Jason Lanier, Extension Educator, UMass Extension Agriculture and Commercial Horticulture Program

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Additional Resources

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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 whenever temperatures are above freezing! 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