UMass Extension Landscape Message #2 - 2011

Scouting Information by Region

Regional Notes

Cape Cod Region (Barnstable) – General Conditions: January was a very cold month on cape Cod, with a low of 3° F early in the morning of January 24. On the other hand, the temperatures were just warm enough that the weekly storms started as snow but then changed to sleet and rain, keeping the overall totals of snowfall below the rest of the State. Pests/Problems: Heavy, wet snow has caused some breakage of evergreen limbs.

Southeast Region (Hanson) – General Conditions: January was a very snowy month here in Plymouth County and elsewhere in Massachusetts. In Boston, it was the 3rd snowiest January on record. On Jan. 12, a major northeaster brought a foot of snow to Hanson with similar amounts to towns around the county. It was heavy, wet snow with strong wind gusts. Many trees and shrubs were buried or bent over by the snow. A number of trees suffered broken limbs which then fell on trees and shrubs below and caused more damage. Birch trees were completely bent over with their tops buried. Many towns in Plymouth County lost power for several hours. January 21 brought more snow (8 inches in Hanson) and high winds. January 23 the temperature was in the single digits and on January 24 temperatures fell below 0 degrees. It was -10° F. in Hanson. January 27 brought another storm with Brockton receiving 13 inches of snow, Hanson 12 inches and Plymouth 8 inches.   The snow banks on the sides of roads are over 6 feet high and roofs have 1-2 feet of snow and ice dams are prevalent. Pests/Problems: The biggest problem now is the amount of damage to trees and shrubs from the heavy wet snow and wind. Many trees and shrubs are buried and splayed. Looks like there will be a lot of remedial pruning next spring. With more snow predicted, damage will probably increase. Phenological Indicators: Viburnum fruit, the gold berries of Ilex verticillata ‘Winter Gold’ and Hawthorne fruit are adding color to an otherwise white landscape.

East Region (Boston) – General Conditions: The first few days of January were unseasonably warm reaching a high of 59° F on the 3rd. Daily temperatures returned to the 30’s for the majority of the month, though we did record a record low of -5° F on the 25th. We have had snow on the ground the entire month as January has seen 4 major snow storms. The blizzard of January 12th brought over 12 inches of heavy snow onto the collection leaving plants covered with a thick blanket of snow. Many tree limbs reached down to the ground under the weight, while others failed, leaving broken limbs scattered throughout the landscape. Shrubs were completely covered and if one was not aware of their presence prior to the storm, it would be impossible to see any sign of these following the snow fall. Many maple limbs buckled under the weight of the snow. Syringa pekinensis ‘Morton’ did particularly poorly as they could not handle the heavy load; the majority of the limbs were lost on both plants. Hamamelis virginiana was in full flower during the storm despite being almost crushed by the weight of the snow. By January 14th, the sun had melted away some heavy covers, allowing certain plants to return (somewhat) to their usual form. The extent of the damage cannot be measured until we are able to fully access the collection and evaluate the plants. The month of January brought a total of 38.3 inches of snow accumulation, just short of the 2005 record of 43.1 inches (and well above the average of 13.5 inches). As of the end of January, total snow accumulation for this winter season has reached 60.3 inches. Since January 12th we have had more than a foot of snow on the ground and as of the 22nd we have consistently had a snow cover of 23 inches.

Metro West (Acton) – General Conditions: Snow covered!  It is difficult to maneuver off the beaten path in the outdoors without a set of snow shoes.  Consistent weekly storms have brought over 60” of snow to the area this winter.  Cool temperatures have preserved the snow.  January experienced 4 days with low temperatures below zero and 5 days with low temps recorded in single digits.  The lowest temperature was recorded on the 24th and that was -9°.  On a brighter note, the day length has grown by 40 minutes!  Sunrise was at 7:01 AM on the 31st and sunset was at 4:48 PM. Pests/Problems:  Fortunately for the Metro West area, the snow has been light and fluffy and has not been wet and heavy as it has been in other regions in Massachusetts where it has caused heavy tree damage.  Unfortunately, there is most likely rodent damage occurring under all this snow cover that will not be visible until snow melt.

Central Region (Boylston) – General Conditions: No report available.

Pioneer Valley Region (Amherst) - General Conditions: Total snowfall the past month in Pioneer Valley was 25-30 inches.  Temperatures were stable, with highs a couple of times in the 40° F range, but generally, high temperatures ranged from mid 20° to low 30° F.  The ground currently has 12-18 inches of snow cover and the ground remained frozen the entire month in the Amherst area.  Pest/Problems:  None was visible yet, but the abundant snow cover may result in deer and other animal browse damage.

Berkshire Region (Great Barrington) - General Conditions: SNOW, SLEET, COLD!  Great time for contractors who do snow plowing, though it is getting tough to find places to deposit new snow as existing snow banks are very high. January had record snowfalls in many areas of the county. Very little snow melt has occurred due to cold temperatures. The snow is great mulch for gardens but also provides cover for voles. Pests/Problems: Vole activity noticed.  The deep snow offers protection for the voles. We won’t be able to determine amount of damage to plants until snows melt. Very little deer browsing observed. Deep snows may have limited deer mobility.

Environmental Data

The following growing-degree-day (GDD) and precipitation data was collected for an approximately four-week period, January 6 through February 2, 2011.  Soil temperature and phenological indicators were observed on or about February 2, 2011.  Total accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments for the 2011 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.

• CAPE COD REGION - Roberta Clark, UMass Extension Horticulturist for Barnstable County, Barnstable.
• SOUTHEAST REGION - Deborah Swanson, UMass Extension Horticulturist for Plymouth County - Retired, Hanson.
• EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists, reporting from the Arnold Arboretum, Jamaica Plain.
• METRO WEST REGION – Julie Coop, Horticulturist, reporting from Acton.
• CENTRAL REGION - Joann Vieira, Superintendent of Horticulture, Tower Hill Botanic Garden, Boylston.
• PIONEER VALLEY REGION - Dan Gillman, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass, Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Insects

Hemlock Woolly Adelgid (HWA) - This serious pest of our Eastern (Canada) hemlock, as well as, the ornamental Carolina hemlock, has been increasing in noticeable numbers within the past two years in Massachusetts mostly due to previous mild winters where temperatures, overall, were on the mild side. However, throughout much of January 2011 night-time temperatures, in particular, have been well below the norm in Massachusetts and this has the potential to have a strong impact on the winter mortality of hemlock woolly adelgid. Similar events occurred in 2000 when 60-80% of adelgid populations were affected and again in 2005 when 90-100% of adelgid populations were killed. Although most people do not enjoy the severe and extended cold, it is an important natural control factor for this very serious insect pest. In the Mid-Atlantic states, and farther into the south, HWA has been killing thousands of hemlocks because cold-enough temperatures do not occur there, which allows numbers of HWA to increase to devastating levels.

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

Diseases

Trees and shrubs - In 2010 there was an assortment of leaf spot, conifer needle cast, and shoot blight diseases on woody plants.  If a severe outbreak of these diseases occurred on high value trees or shrubs, make a note of that when making plans for next season.  Reduce pathogen inoculum levels (disease pressure) around host plants by removing dead branches and foliage around susceptible plants.

Diagnostic Lab Woody Plant Report: The following are some of the interesting woody plant disease/abiotic disorder samples received at the UMass Extension Plant Diagnostic Lab in Amherst during the period January 1 through February 2, 2011:

• Pitch pine - mature tree in apparent good health with several fungal fruiting structures erupting through the bark 5-10 feet up on the trunk; Phellinus pini heartwood decay, which can pose a hazard to nearby people and structures.
• Austrian pines - growing in ~15 year-old hedge with scattered stunted and brown needles at branch tips; Diplodia blight worsened by chronic water shortage.
• Sugar maple - ~10% of branches in upper crown of mature tree with branch dieback; negative results for Verticillium wilt but positive for Valsa canker with soil compaction contributing to the problem.
• Mountain laurel - ~25 year old plant with leaf spots/blotches and diminished vigor; Cercospora leaf spot.

Reported by Dan Gillman, Plant Pathologist, UMass Extension Plant Diagnostic Lab, Amherst.