UMass Extension Landscape Message #7
April 17, 2009

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Quick Info Menu ------------------------------- SCOUTING INFORMATION REGIONAL NOTES - Cape Cod - Southeast - East - Metro West Waltham - Metro West Hopkinton - Central - Pioneer Valley - Berkshire ENVIRONMENTAL DATA PHENOLOGY WOODY ORNAMENTALS - Insects - Diseases - Weeds LANDSCAPE TURF INFO RESOURCES DIAGNOSTIC SERVICES Use this menu to instantly jump to any portion of the message!

The LANDSCAPE MESSAGE is an educational newsletter intended to guide landscape, nursery and urban forestry professionals in identifying pests in the landscape, monitoring their development, planning management strategies and creating site-specific records for future management reference. UMass Extension has updated this issue to provide timely pest management information and the latest regional news and environmental data throughout Massachusetts. During the months of April through June, this newsletter will be published weekly. The next update will be available on or about April 24, 2009. Missed a previous message? Visit the Landscape Message Archive. Interested in additional turf-oriented content? UMass Extension Turf Program Management Updates

SCOUTING INFORMATION BY REGION

REGIONAL NOTES -

Cape Cod Region (Barnstable) – General Conditions: Overall weather conditions have been cooler than normal.  We received a good soaking rain on the 11th and very chilly weather on the 12th.  Plant development is progressing slowly, but lawns are greening up nicely.  Spring tasks are underway in the landscape.  Daffodils are a cheery spot of color.  Pests/Problems:  Snow mold is still evident on turf.  Winter moth eggs have yet to hatch but are expected to hatch soon.  Adult deer ticks are active. 

Southeast Region (Hanson) – General Conditions: Sunny weather with days in the low 50's but with some nights below freezing; be cautious using dormant oil in these conditions.  (Please see the Woody Ornamental Insect section of this message regarding the use of dormant oil).  Approximately 1 inch of rain was recorded in Halifax, MA over the weekend with cool daytime temperatures and wind.  Cooler weather is slowing plant development.  Forsythia buds are still plump and yellow and starting to open in some areas and still in tight bud in others.  Cornus mas (Corneliancherry Dogwood), red maple, Lonicera fragrantissima (Fragrant Honeysuckle), Abeliophyllum distichum (White Forsythia), Cornus mas, pussy willow, Pieris 'Brouwer's Beauty', Pieris floribunda, Pieris japonica, Helleborus niger, H. foetidus, H. x hybridus (formerly orientalis), Corydalis solida, Petasites japonicus, Omphalodes verna, Trillium, daffodils, Scilla sibirica, Pulmonaria, and Vinca minor are in full bloom.  Violets and star magnolia are beginning bloom.  Hamamelis mollis 'Pallida' and  Hamamelis x intermedia 'Arnold Promise' are past bloom.  Lawns have started to green up.  Spring peepers continue to peep.  Pests/Problems:  Newly hatched winter moth caterpillars were found in the developing foliage of crabapple trees in the towns of Needham, MA and Hanson, MA on April 15th. Curiously, on the same property in Hanson, the Winter moth caterpillar eggs that are being used to monitor hatch are pinkish-red and have not started to hatch. Conclusion, monitor developing foliage on trees with a history of winter moth damage. The caterpillars may be present. They are very small at this stage.  Based on moth flight last fall, we expect to see high numbers of winter moth caterpillars this spring. Click here for an updated winter moth fact sheet .  Deer ticks are active; conduct tick checks frequently, especially after yard cleanups.  Boxelder bugs and red lily leaf beetles are active.  Deer and rabbits continue to browse emerging perennials, as well as woody plants.  We continue to see winter damage or burn on broadleaved evergreens (holly, boxwood, rhododendron, etc.).  Salt damage is evident on needled evergreens (hemlocks, white pine) located near roadways.  Bittercress (Cardamine hirsuta) andchickweed are in full bloom.  Dandelions are starting to bloom.

East Region (Boston) – General Conditions: Cool temperatures with some rain and wind have dominated the weather for the past week or so.  Minus the wind, this is perfect weather for transplanting trees and shrubs.  Not sure what night it was, but the flowers on the magnolias got lightly nipped by the cool temps.  The Abeliophyllum distichum, the white flowering forsythia as well as the pink flowering form 'Roseum' arein full bloom as is the Rh. mucronulatum  'Cornell Pink' and Jeffersonia diphylla.Pests/Problems:  Nothing new to report.  Just continuing to prune out the brown and dead branches on evergreen shrubs from winter kill and the completely girdled stems on the shrubs devoured by the rodents.

Metro West (Waltham) – General Conditions: No report this week.

Metro West (Hopkinton) – General Conditions: This past week has brought cold nights and warm days with temperatures overall below average.  Soils are moist, but no longer saturated.  Peepers could be heard at the beginning of the week during the evening.  Cold nights have held lawns back, so it will be this coming weekend before they really need a mowing.  Pests/Problems: Rabbits are active at night.   Their population seems to have increased over last year.   Deer continue to browse.

Central Region (Boylston) – General Conditions: Cool nights have kept the early spring bulbs in a state of stasis.  Squill (Scilla siberica), Glory of the Snow (Chionodoxa luciliae), early Daffodils (Narcissus cvs.), remain in full bloom.  Some of the shrubs have advanced―White Forsythia (Abeliophyllum distichum); Fragrant Honeysuckles (Lonicera x purpusii, L. fragrantissima), and Harry Lauder's Walking Stick (Corylus avellana 'Contorta') are in full bloom.  Hellebores continue to bloom. Pigsqueak (Bergenia sp.), Bloodroot (Sanguinaria canadensis), Corydalis solida, and Lungworts (Pulmonaria cvs.) are begining to show color.  Pests/Problems:  No pests or diseases evident at this point         

Pioneer Valley Region (Amherst) - General Conditions: The continuation of cool temperatures is slowing the arrival of spring.  However, this is prolonging the flowering of daffodils, red maples, and Corneliancherry dogwoods.  The hyacinths, forsythias, Japanese flowering quince, and star magnolias joined in the chorus of blooms in the last week.  Adequate moisture and coolness is also stimulating growth in lawns.  Pests/Problems:  There is a fair amount of winter desiccation injury visible on rhododendrons along with a scattering of broken stems, rhododendron borer, and Botryosphaeria canker to complicate some of the situations.  The recent cold temperatures suppressed fungal disease activity so far this spring, but if the wetness continues and the temperatures warm, that favors leaf spot and blight disease infections.  When shopping for garden vegetables, flowers, herbs, and new woody landscape plants select disease resistant varieties if possible.

Berkshire Region (Great Barrington) - General Conditions: A very cool week has kept most plants in a state of suspended animation, though most lawns are greening up nicely and grass is growing.  With weather warming over this week, plant growth and pest appearance should accelerate.  Pests/Problems:  No new pests to report.  

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a one-week period, April 8, 2009 through April 14, 2009.  Soil temperature and phenological indicators were observed on April 14, 2009.  Accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments from the beginning of the current 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.

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, b/full, full, f/end, end)
PLANT NAME (Botanic/Common)	CAPE	SOUTH EAST	EAST	METRO W.		CENT.	P.V.	BERK.
				Waltham	Hopkinton
Rhododendron 'P. J. M.'	*	*	*	*	full	*	*	*
Magnolia soulangiana (Saucer Magnolia)	*	*	begin	*	*	*	begin	*
Prunus serrulata (Japanes Flowering Cherry)	begin	*	*	*	*	*	begin	*
Forsythia x intermedia (Border Forsythia)	begin	begin	full	full	full	begin	b/full	begin
Rhododendron mucronulatum (Korean Rhododendron)	b/full	b/full	full	full	full	*	*	*
Magnolia stellata (Star Magnolia)	begin	begin	full	full	full	begin	full	*
Pieris japonica (Japanese Pieris)	full	full	full	full	full	full	full	full
Cornus mas (Corneliancherry Dogwood)	full	full	end	*	full	full	f/end	full
Acer rubrum (Red Maple)	f/end	full	end	full	full	full	f/end	full
* = no activity to report/information not available

CAPE COD REGION - Roberta Clark, Horticulturist for Barnstable County, Barnstable.

SOUTHEAST REGION - Deborah Swanson, Horticulturist for UMass Extension in Plymouth County, Hanson.

EAST REGION - Julie Coop, Manager of Plant Health, Arnold Arboretum, Harvard University, Jamaica Plain.

METRO WEST REGION – James Martin, Consulting Arborist, reporting from the UMass Extension Center, Waltham.

METRO WEST REGION – Mark Sawyer, Horticulturist, Weston Nurseries, Hopkinton.

CENTRAL REGION - Joann Vieira, Superintendent of Horticulture, Tower Hill Botanic Garden, Boylston.

PIONEER VALLEY - Dan Gillman, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass, Amherst.

BERKSHIRES - Ron Kujawski, Specialist, UMass Extension Landscape, Nursery & Urban Forestry Program, Amherst.

WOODY ORNAMENTALS

INSECTS -

Winter Moth flight last November/December was substantially more prevalent that it has been in Massachusetts for several years.  This is a strong indicator that the numbers of caterpillars this spring will be up considerably for the first time in 3 years and serious damage to trees, apple crops, and blueberries may occur.  Winter moth caterpillars hatch early (approximately 20-50 GDD or about mid April) and wriggle into swelling buds where they feed and harm leaf and flower buds.  Dormant oil sprays for fruit tree crops (apple, blueberry) may be prudent.  Once the foliage is open, these caterpillars then feed freely and can be managed with Bacillus thuringiensis Kurstaki (B.t.K.) while they are still small, or with a product that contains spinosad, or with a registered pyrethroid product.  Winter moth egg hatch should occur within the next week if warmer weather persists.

NOTE on Dormant Oil Sprays:  Care should be taken at this time of the year when choosing to use dormant oil sprays.  In the cooler regions of the state, such as Plymouth County, which has only accumulated approximately 26 GDD to date, may still allow for dormant oil use in many cases but be very careful if new plant growth is occurring.  Also, oil sprays should not be applied if freezing temperatures may result 24-48 hours after application.  Spraying oils on evergreens, especially conifers, can result in phytotoxicity at this time of year if conditions are not correct.  In central MA and the Amherst area, it may be too late for dormant oil sprays now.

Hemlock Woolly Adelgid (HWA) is rebounding from the significant winter mortality it experienced in 2005 in Massachusetts.  Monitor for the new egg masses that are appearing now.  If the weather is conducive to apply dormant oils, take advantage of this option where the numbers of HWA are increasing.  Later, HWA can be managed with oil sprays at the summer rate or with systemic applications of imidacloprid. 

Viburnum Leaf Beetle was found in MA during the 2008 growing season in several different counties.  It was known to be established in Berkshire county for the past 3 years but has now been identified in Franklin, Bristol, and northern Worcester County.  Many of the finds suggest strongly that this serious pest is being moved on nursery plants throughout the Northeast.  Inspect now for the eggs, which were deposited on the terminal twigs last season.  When found, such twigs should be removed and destroyed prior to the eggs hatching in late April through early May.  Larvae will appear soon after the leaves emerge and feed until approximately mid June whereupon they will pupate.  Adult beetles appear about 2-3 weeks later and feed until the first frost.  Much damage can occur, especially from the larvae.    For more details and preferred viburnum host species, visit: http://www.hort.cornell.edu/vlb Spinosad products work well for the larvae.  Inspect viburnum twigs now for any signs of eggs; prune out and destroy if found.

Asian Longhorned Beetle (ALB) was found in Worcester, MA last August.  The Regulated Area is now at 64 square miles.  Approximately 19,000 trees have been removed and rendered into wood chips since January 2009.  It is estimated that this population may have been in Worcester for at least 15 years.  Survey work has renewed within the Regulated Area, and it is already known that many more trees are infested.  Everyone must be on the lookout for this pest and report any potential finds immediately if eradication efforts are to be successful.  Also, take great care when moving firewood to avoid moving this very serious killer of forest and landscape hardwood trees.

• To report a potential ALB find: http://massnrc.org/pests/alb
• To see “How to Recognize ALB” slide presentation: recognize_alb_ppt.pdf

Balsam Twig Aphid will be active soon.  The ‘stem mothers’ can be seen with a hand lens.  These pale green aphids will feed on true firs, in particular, and then produce many offspring that will feed on the new needles as they emerge from the buds causing them to twist and curl.  This insect also produces much honeydew, which causes new (twisted) needles to stick together.  This pest is of most concern in Christmas tree plantations but can be problematic in the landscape.  If found in significant number, treat with a registered pyrethroid or with a horticultural oil if weather and plant phenology allows.

Mining Bees and Ground Bees: Many reports have been received within the past week concerning the activity in large numbers where the soil is suitable for them to build tunnels for offspring.  Dozens or more at a time can be seen flying above the ground and entering into anthill-like holes in the ground.  There are numerous species, but virtually all are quite docile and rarely, if ever, sting.  However, their presence usually creates alarm for some people.  Their busiest time is now and will continue for the next several weeks.  After that, they usually become unnoticeable.  Treatments are generally not applied given that these insects are important pollinators.

Hemlock Eriophyid Mites will be active soon, if not already in the warmer regions.  These tiny yet just visible peg-shaped and 4-legged mites feed openly on the needle surfaces of hemlock.  Inspect carefully for their presence.  Affected trees often appear slightly chlorotic.  These mites can cause harm if appearing in large numbers.  They remain active until early to mid June.  When found to be numerous on any particular hemlock, treat with an oil spray (weather permitting) or with one of the registered pyrethroid insecticides.

Winterkill:  Many evergreen plants, especially rhododendrons, experienced winterkill this past winter.  The drooping and browning foliage now was actually affected last January or February.  On cold but sunny days, the foliage of rhododendrons may actually perform some photosynthesis; but when the sun sets and the night becomes very cold, the foliage cannot replace the lost water from transpiration due to the plant’s roots being in frozen ground.  The result is the death of foliage.  This is often seen randomly within one plant and throughout plantings due to the exact micro-climate that forms around each shoot under such conditions.  Some will be killed while others just escape injury.  Wait a couple more weeks to see exactly which shoots are dead and then prune out the killed branches.

Inkberry Leafminer:  This pest overwinters as a larva within the foliage of  inkberry.  The characteristic brown leaf tips usually do not appear until January and, thus, get missed by many.  Hold browned leaves up to the light to see if the leaf has been mined or cut into the browned area in search of the larva.  If numerous mines are found, wait until mid to late May to hang yellow sticky cards on the affected plants.  Once the adult flies appear, treat with a pyrethroid insecticide to kill the adults and to limit the incidence of re-infestation of the same plants.  Foliage without mines but possessing browned tips may have experienced some winter injury.

Reported by Robert Childs, Entomologist, Plant, Soil and Insect Sciences Department, UMass Extension, Amherst.

WEEDS -

Treat winter annual and perennial weeds in ornamental beds with glyphosate or glufosinate.  These applications are easier if done now before woody ornamentals leaf out.  The new growth of herbaceous perennial ornamentals can be very susceptible to spray drift, so exercise extreme caution.  Non-chemical products containing clove oil, citric acid, acetic acid, or orange extract can be used on small winter annuals but not on large winter annuals or perennials.  Many winter annuals are just beginning to flower and have not set seed and should be controlled now.  

Preemergence herbicides for the control of summer annual weeds can be applied to weed-free ornamental beds now.

Remember, landscape mulches are the first defense against weeds in ornamental beds.  Apply mulch or replenish existing mulch at the beginning of the season.  Existing weeds in ornamental beds should be controlled before mulching is done.

Reported by Randall Prostak, Weed Specialist, UMass Extension Landscape, Nursery and Urban Forestry Program, Amherst.

LANDSCAPE TURF

WEEDS -

Preemergence herbicides for crabgrass and annual grass control can begin now. You cannot count on the cool weather to persist, and this will give you enough time to treat all your customers.  If split applications are used in your crabgrass control program, apply 50% of your active ingredient now.  Never apply preemergence products to turf areas that are still littered with winter debris.  Rake and clean turf to prevent “application shadows.”  Never apply preemergence products to water-logged soils.

It is still too early to treat perennial broadleaf weeds.  

If broadleaf winter annual weeds are problematic at this point, they can be treated.  Broadleaf winter annuals can be of concern in turf areas that were established late fall.

Reported by Randall Prostak, Weed Specialist, UMass Extension Landscape, Nursery and Urban Forestry Program, Amherst.

DIAGNOSTIC SERVICES

UMass Laboratory Diagnoses Turf and Landscape Problems - Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. 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. Send specimens and payment (payable to the University of Massachusetts) to UMass Extension Plant Diagnostic Lab, Holdsworth Natural Resources Center, 160 Holdsworth Way, UMass, Amherst, MA 01003. The fee for a woody plant disease analysis is $50; the fee for turf disease analysis or nematode assay is $75. All insect, weed and turfgrass identification samples are $25 each. For more detailed submission instructions see http://www.umass.edu/agland/diagnostics

Soil and Plant Tissue Testing - The University of Massachusetts Soil and Plant Tissue 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 Tissue 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 tissue Testing Laboratory web site at: http://www.umass.edu/soiltest Alternatively, call the lab at (413) 545-2311.

NEXT UPDATE: The next issue will be available on or about April 24, 2009.

This message is produced by the UMASS Extension, Landscape, Nursery and Urban Forestry Program. The copy is prepared by Anna Greene from data and reports provided by the staff and faculty of the UMass Landscape, Nursery and Urban Forestry Program and the UMASS Extension Turf Program as well as cooperating horticulturists and Green Industry professionals. The text is adapted for access via the Internet by Jason Lanier.

DISCLAIMER. This message is intended for commercial use. UMass Extension assumes no liability for recommendations. It is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The use of trade names (™) does not imply endorsement. Similarly, there may be other products you prefer to use.

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