UMASS Landscaping Update

Pioneer Valley (Amherst)

General Conditions:

With Independence Day now behind us, we’ve settled into the dog days of summer. Conditions in the Pioneer Valley are feeling very similar to last year at this time, with a steady supply of heat, high humidity, and scattered (sometimes heavy) showers. The patchy development of these storms means some areas have been flush with rainfall while others could use a bit more. Since our last report, precipitation totals have ranged from 1.5–3” in Hampden County, 1.25–4” in Hampshire County, and 2–5” in Franklin County.

The strong plant growth this season combined with the rain and winds means some plants are leaning and flopping all over the garden. There’s an abundance of pollinator activity across the landscape and a variety of perennials are in full bloom. Soil moisture is generally good depending on the specific location, but closely monitor new transplants given the high heat. While the current season’s growth on woody plants is mostly hardened off, transpirational water loss for cooling can sap a significant percentage of daily water usage.

Pests/Problems:

Annual fruiting bodies of the fungal wood-rotting pathogen Niveoporofomes spraguei are forming at the base of infected oaks. Powdery mildew on dogwood is readily visible at present. Symptoms include reddening, white powdery masses, and leaf distortion. Any time of year is a good time to prune blighted stems and small branches from tree and shrub canopies. Opportunistic cankering pathogens are common and destructive on stressed and weakened hosts.

Insect activity and feeding remains high right now. At times, sporadic leaf chewing and defoliation is hard to assign to a particular pest, given the diverse array of insects along with slugs and earwigs (among others). Hemlock woolly adelgid (Adelges tsugae) populations are high this season due to the mild winter. Invasive scarab beetles (Asiatic, Oriental and Japanese) are locally abundant and causing damage on a variety of herbaceous and woody plants. Leaf notching from vine weevils has been observed on rhododendrons. Hibiscus sawfly (Atomacera decepta) injury is high on untreated plants.