UMASS Landscaping update

Pioneer Valley (Amherst)

General Conditions: 

Despite worsening drought conditions across the Pioneer Valley, there were three rain events over this past reporting period that provided some badly needed moisture. Two of these events (September 23-25 & October 12–14) were long duration storms that provided a soaking rainfall. Total accumulations from September 23 to October 14, across the tri-counties, spanned 3.1–4.4”.

While it will take considerably more rainfall to pull us out of our current water deficit, soils are moist to wet in the upper horizons. Turfgrasses have greened up dramatically, and the mowing season continues. Hopefully, deciduous hardwoods entering dormancy were able to take up some of this water to reduce the drought stress they have suffered from the past few months. Conifers are more readily able to utilize the increased soil moisture as they slowly enter winter dormancy.

The first seasonal frost on October 10 was widespread throughout most of the tri-counties, when temperatures dipped as low as the upper 20s in some areas. This abruptly ended the growing season for popular annuals like Zinnia, Coleus, and Begonia.

The fall foliage appears a bit muted this season, owing in part to the dry conditions in late summer and early autumn. Still, there are many trees producing their typical stellar display of red, orange and yellow.

Squirrel and chipmunk activity are at a fever pitch as they work to prepare winter stores of acorns and other nuts. There can be dozens of small holes dug in mulched beds right now.

There was a slight uptick in mosquito activity after the late September rain, but they seem all but gone now. After an early summer surge of mosquitos, the dry conditions tempered their populations in late summer.

The long-term forecast calls for cool to mild temperatures and more rainfall.

Pests/Problems:

With cooling temperatures upon us, it’s time to move pesticides indoors to prevent freezing over the winter.

A plan should be in place for protecting plants most susceptible to winter browse damage from deer and rabbits (e.g. yews, arborvitae, among many others). This can be achieved with fencing and/or repellents. Meadow voles can also cause significant damage by chewing bark at the base of hardwoods and evergreens. Protective screening or guards may be necessary to discourage their actions.

Composting leaf mulch on site from trees with serious foliar diseases is generally safe in most cases. Ensure the leaves are chopped as well as possible and mixed with foliage from other trees to encourage a mixture of microbes present for decomposition. The biggest risk comes from large volumes of untended leaves directly underneath trees that were badly diseased this year. Yet, in some cases, even with good sanitation, trees will be infected next year and little can be done. Any time of the year is good for pruning blighted and dead twigs and small branches from the canopy of trees and shrubs. Removal of this material reduces overwintering inoculum used by many opportunistic cankering pathogens.

Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from Amherst.