UMass Extension Landscape Message #5
April 3, 2009

Feel that the message below is not the latest one? Try pressing the 'refresh' or 'reload' button in your web browser.

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 10, 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: March remained somewhat cooler than normal, with a few days where temperatures rose into the 50’s F.  Several rain events occurred over the past two-week reporting period, with heavy rains and wind occurring on March 29.  Early spring bulbs such as Iris reticulata and crocus are in full bloom.  Helleborus is in bloom, along with pussy willow.  Pests/Problems:  Snow mold is evident on turf.  Crows and starlings are digging up turf as well.  Adult deer ticks are active any time temperatures are over 35° F.  Winter desiccation is showing up on broadleaf evergreens.

Southeast Region (Hanson) – General Conditions: No report this week.

East Region (Boston) – General Conditions: This past week’s rainfall, totaling .99 of an inch, brought the month’s total accumulation up to 3.1 inches, which falls short of the monthly average and far short of the above average 5.65 inches of rain that we received in March 2008.  The high temperature for the past two weeks was 61° F on March 18.  Unfortunately, we did not gain any degree days from it because that evening’s low temperature was 35° F.  Our low for the past two weeks was 21° on the 23rd and the 24th.  Hamamelis continue to bloom, thanks to the cool weather.  Daphne mezereum f. alba and Lonicera korlkowii are in full bloom and are as fragrant as ever.  Magnolia stellata buds are swelling and exposing bits of color.  Pests/Problems:  Hemlock woolly adelgid cottony egg masses are showing up on the Tsuga.  Alliaria petiolata  and Lamium purpureum, both cold tolerant weeds, are appearing in the landscape.

Metro West (Waltham) – General Conditions: A significant number of broadleaved evergreens, rhododendrons in particular, are showing symptoms of winter injury.

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

Central Region (Boylston) – General Conditions: Early bulbs are in full swing including Crocus, Scilla, Galanthus, Iris reticulata and I. danfordiae.  Hellebores (H. x hybridus) are also blooming.  Pests/Problems:  No pest or disease problems are evident at this point.  Evergreens are showing winter damage.     

Pioneer Valley Region (Amherst) - General Conditions: Lawns are greening up with small rounded patches of brown due to damage from snow molds.  In most cases, the browned areas will green up, but they will be later than the grass without the infection.  See the turf disease section below for tips on snow mold management. The UMass Extension Turf Program web site http://www.umassturf.org also has a snow mold fact sheet with detailed information.  Crocuses are abundant and provide cheery color to the landscape along with the silver maples, red maples, and Corneliancherry dogwoods.  Soil moisture is drying, but with the cool temperatures and a recent soaking rain, it appears adequate.  Pests/Problems:  In addition to snow molds, winter dehydration on both needled- and broad-leaved evergreens is evident on exposed sites.  This is primarily due to exposure to sun and wind when the ground was frozen.  

Berkshire Region (Great Barrington) - General Conditions: Soils were drying, but recent rains have provided enough moisture to prompt growth of grass.  Honey bees are very active.  Pests/Problems:  Pests include ticks, browsing deer, carpenter ants, and even an occasional mosquito.

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a two-week period, March 18, 2009 through March 31, 2009.  Soil temperature and phenological indicators were observed on March 31, 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
Pieris japonica (Japanese Pieris)	begin	*	begin	begin	*	*	begin	*
Cornus mas (Corneliancherry Dogwood)	begin	*	full	*	*	begin	full	begin
Acer rubrum (Red Maple)	b/full	*	full	*	*	full	b/full	begin
Acer saccharinum (Silver Maple)	f/end	*	full	*	*	*	f/end	*
Hamamelis x intermidia (Witchhazel hybrids)	f/end	*	end	*	*	full	f/end	full
Hamamelis mollis (Chinese Witchhazel hybrids)	*	*	end	*	*	full	*	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 -

As the snow melts and exposes bare ground, we await the first activity of the White Pine Weevil. These small (approximately 1/4 inch) weevils overwinter in the adult stage in protected areas in such places as leaf litter, rock walls, and elsewhere.  The adult female seeks the terminal growth of white pines and many different spruces where they will chew pits and lay eggs.  The larvae soon hatch and tunnel downward in this apical shoot eventually killing 2-3 years of growth.  The top whirl of lateral branches will then start to compete to become a new leader thus creating a multi-trunk form.  This attack does not kill the host tree but merely changes its normal habit of growth.  Eventually, attacked trees will become bushier; and if the trees are utilized as a privacy screen or windbreak, this may be desirable.  Infested shoots can be pruned away before June and destroyed.  Then, a new leader can be chosen from the best lateral branch on the remaining top whirl.  Pyrethroid spray(s) applied early can help to deter attack from this pest.

Winter Moth flight last November/December was substantially more prevalent than 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.

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.  Once 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–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.

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

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

LANDSCAPE TURF

DISEASES -

Snow molds are patch diseases caused by various cold-loving fungal pathogens and appear most often in early spring as snow melts.  Typhula blight and Microdochium patch are the two most common culprits on turf areas such as home lawns, sports fields, and golf courses.  This year snow molds caused significant damage on turfgrasses throughout the New England region due to prolonged snow cover.  The following are some cultural practices for the management of snow molds.

Typhula Blight (Gray and Speckled Snow Molds)

• Pathogens:  Typhula incarnata, Typhula ishikariensis. 
• Hosts:  Most susceptible - bentgrasses, annual bluegrass, tall fescue.  Moderately susceptible - perennial ryegrass, fine fescues.  Least susceptible - Kentucky bluegrass, colonial bentgrass. 
• Optimum Conditions:  Cold (30-40º F), wet weather; prolongedsnow cover; high nitrogen fertility. 
• Symptoms:  Melting snow reveals circular gray or straw colored patches from a few inches to three feet or more in diameter.  The grass in these areas is usually matted down and grayish-white mycelium is often visible at the edge of the patches.  Sclerotia (resting structures) of the fungi can often be found in and among the diseased grass blades.  Susceptible turfgrasses are usually severely thinned or may even be killed.  T. incarnata has large, rust-colored sclerotia, while the sclerotia of T. ishikariensis are smaller, spherical and black (about the size of a pinhead).  
• Cultural Control:  Plant less susceptible Kentucky bluegrass varieties for home lawns, sports fields and/or colonial bentgrass for golf courses fairways and tees.  Avoid heavy, (> 0.5 lb/1000 ft.2) late season applications of water-soluble nitrogen and continue to mow the grass until dormancy in the fall.  Manage excessive thatch and reduce soil compaction in the fall.  Avoid compacting snow where damage has previously occurred.  In the spring, rake and fertilize damaged areas to stimulate turfgrass regrowth from viable crowns since only leaves are killed in most cases.  Remove snow and improve drainage so that water melt from snow will dry rapidly in disease susceptible areas in early spring.  Severely damaged turf may require reseeding.  Preventative fall fungicide applications are critical on highly managed turf areas.  Curative applications in late winter or early spring are usually not effective.

Microdochium Patch (Pink Snow Mold):

• Pathogen:  Microdochium nivale.
• Hosts:  Most susceptible - annual bluegrass, bentgrasses.  Moderately susceptible - perennial ryegrass.  Least susceptible - Kentucky bluegrass, fine fescues.  
• Optimum Conditions:  Cool-cold (30-60º F), wet weather;high nitrogen fertility; alkaline soils; snow cover (not necessary). 
• Symptoms:  Wet grass is covered withcircular patches of tan to white grass from a few inches to a few feet in diameter.  The leaves of affected turfgrasses often mat together, and pink mycelium is commonly visible at the edge of the patches.  Unlike Typhula spp., M. nivale does not produce sclerotia.  Mycelium and asexual spores (called conidia) of the fungus give the border of the patches a distinct pink to reddish brown color.  In the absence of snow cover, and when weather is cool and wet, water-soaked patches of grass one to a few inches in diameter are common.  These patches are grayish to white in the center with reddish-brown borders.  At higher temperatures (50-65º F), the fungus is capable of causing a yellow blighting of higher cut grasses during wet periods. 
• Cultural Control:  Plant less susceptible turfgrass species such as Kentucky bluegrass or fine-leaved fescues.  Avoid late season applications of readily available nitrogen and mow the grass until dormancy in the fall.  The disease is more severe under alkaline conditions, so maintaining a pH of 7.0 or less in the soil profile will reduce disease damage.  In the spring, rake and fertilize damaged areas to stimulate turfgrass regrowth.  Severely damaged turf may require reseeding.       

If you have questions about fungicide selections for snow mold control, please contact Dr. Geunhwa Jung at jung@psis.umass.edu or 413-545-2243.

Reported by Dr. Geunhwa Jung, Plant Pathologist, Department of Plant, Soil and Insect Sciences, UMass, 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 10, 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.

Comments or suggestions in regard to the Landscape Message? Please e-mail the webmaster.

Missed a previous message? Visit the Landscape Message Archive.