General Conditions:

In recent days, seasonal temperatures have descended across the Pioneer Valley and with the rapidly decreasing daylight, it’s really feeling like autumn now. With the blazing heat in early September and persistent wet weather, that fall feeling was slow to build this year. The first half of October ranged from muggy and wet to pleasant and sunny. Low temperatures in the lower 40s have occurred in recent days, but we’ve been nowhere near our first frost. According to the Northeast Regional Climate Center, the average date for the first frost in our region is roughly 10/10–10/15. Three major rainfall events occurred over the past reporting period on 9/23–25, 9/29–30, and 10/7. Accumulations ranged from 3–5” across Franklin and northern Hampshire Counties and 5–7” across southern Hampshire and Hampden Counties. More than half of this rain fell on 9/29–30 when >3” was recorded at the Easthampton gauge. Even during a season with countless heavy rainstorms, the barrage of intense rain on 9/29 stood out. The forecasted rain on 10/14 would make it the fourth consecutive rainy Saturday. As such, soil moisture remains high and supplemental watering needs have been extremely limited in recent weeks. It’s been a good season for transplanting conifers, as many will produce an abundance of new roots in late summer and autumn. Turfgrasses remain lush and the demand for mowing still hasn’t slowed. However, the long-term forecast calls for highs in the 50s and this should at least increase the interval. One of the highlights of the fall foliage season is a mature sugar maple with a blazing orange canopy contrasted against the dark grey trunk. Yet, this year many sugar maples are exhibiting a blotchy yellow-brown color due to a variety of foliar diseases initiated by the heavy rains. Interestingly, many red maples have been shining brightly, providing some of the best autumn color so far. While red maples are susceptible to the same foliar disease fungi as sugar maple, many trees have proved more resistant. According to the most recent USFS forest inventory and analysis, red maple is the most abundant tree in the Commonwealth. Of the ~1.48 billion trees in the Bay State, approximately 300 million (>20%) are red maples (https://www.fs.usda.gov/research/treesearch/60977(link is external)

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Pests/Problems:

Pest and pathogen activity is slowing as temperatures decline and trees and shrubs begin to enter dormancy. The abundant rain and high humidity provided ideal conditions for many anthracnose, foliar disease, needle blight, and twig/branch cankering pathogens this season. However, the rain was also beneficial for many trees and shrubs, allowing them to allocate resources to defense against various diseases. Continue to prune and discard blighted twigs and branches prior to the dormant season. Reducing inoculum in the canopy can lessen disease severity next growing season. Stink bugs (Halyomorpha halys) are now a frequent sight on window screens and inside homes and buildings. Mosquito populations are still high, but the cooler temperatures and low humidity have suppressed the biting hordes over the past week. Mature green June beetle (Cotinis nitida) larvae can be encountered in turfgrass, vegetable gardens and ornamental beds. Various animals and even birds prey upon these enormous grubs, keeping populations under control. In certain settings, mowing or collecting discarded foliage can reduce foliar disease inoculum that will initiate new infections in the spring. However, some pathogens are so widespread that little can be done to eliminate the development of infections. While mowing maple and birch leaves into lawns can provide beneficial nutrients, the thick and waxy leaves of red and black oak will not soon decompose.