UMASS Landscaping Updates

General Conditions:

It’s been a gorgeous autumn season throughout the Pioneer Valley. Leaf color reached its peak over the holiday weekend with both sugar and red maple in their full glory. Mild days with bright sun and cool nights have made for some prime conditions to be outside. The beautiful weather aside, the lack of precipitation since mid-August is a significant concern as trees and shrubs enter the dormant season. Drought stress can impact the cold acclimation process, making woody plants more susceptible to freeze injury during the winter months. Since our last soaking rainfall in mid-August (8/19), there have been only four rain events at the Easthampton gauge (9/7, 9/26, 10/7, and 10/13–14) with a combined accumulation of 1.32”. At a wider scale, most weather stations in Hampshire and Hampden Counties have similar totals over this span (1–2” from 8/20 to 10/16) while Franklin County has fared somewhat better with 3–3.5”. Across the UMass campus, surface soils are very dry and lower soil horizons also have limited moisture. While water demands are currently low, new deciduous transplants should be watered through the end of October and evergreens through November. Patchy frost occurred on the morning of 10/15 in the valley bottom with the potential for additional scattered frosts in the long-term forecast.

Pests/Problems:

As pest and pathogen activity wanes in parallel with plant activity, there are very few insects and diseases that require active management at this time. Continue to scout for the presence of conks and mushrooms produced with root and lower trunk rot pathogens of hardwoods and conifers. In many cases, the presence of the fruiting bodies may be the only indication the tree is infected, even when serious decay is present. Reducing overwintering inoculum through fall clean ups can help to manage common foliar diseases that occur throughout the managed landscape, especially foliar anthracnose of deciduous trees and shrubs. Many foliar pathogens overwinter on diseased, discarded leaves. When left at the site, they can readily sporulate next spring to infect newly developing foliage.

Now is a good time to start applying deer and rodent repellents to susceptible plants. Scout landscape beds for evidence of voles so that repellents can be targeted against these root and bark eating pests.

The autumn season is a good time to excavate the root flare of trees and shrubs to ensure that girdling and circling roots are not forming. Pruning of larger girdling roots is better performed in winter and spring but identifying these problematic roots can be done at almost any time. Avoid any significant canopy pruning during the fall season, as it can make certain trees more susceptible to cold temperature injury.