Pioneer Valley (Amherst)

General Conditions:

Welcome back for another season of the Landscape Message. Spring has already taken hold across the Pioneer Valley as last fall’s prediction of a warm and wet El Niño winter held true. The tri-counties saw only limited snowfall and we had just one significant storm in early January, when ~7–9” of snow accumulated and then quickly melted. In addition, the region experienced only a brief stretch of very cold temperatures, from January 18–22, when lows hovered in the single digits. February, typically the snowiest month of winter in recent years, was sunny, mild and dry. Witchhazels and snow drops started flowering early and by the beginning of March, high temperatures were consistently hitting the lower to upper 50s. A brief stretch in the upper 60s (to even 70°F) on March 13 & 14 really pushed plants along. Flowering cherry, viburnum, clematis, honeysuckle and multiflora rose have all started leafing out while elm, silver maple and red maple are in full flower. Peach, Forsythia, andromeda, and azalea have started flowering (some are full flower) and numerous other plants have swollen buds, including yew, pine, and Japanese maple. Right now, there are major differences in plant phenology between warm, south-facing microclimates and north-facing, shaded landscapes. Ah, but the meteorological start of spring has brought a return to winter. At the time of writing, the forecast calls for a low near 20°F on 3/21 and the possibility of sleet and snow over the weekend. Hopefully this doesn’t damage flower buds and newly developing leaves.

Pests/Problems:

Beech leaf disease is certain to be more widespread throughout the tri-counties this year with higher levels of disease severity. While scientists continue to learn more about the nematode and disease development, management efforts remain limited. This upcoming season should prove helpful in determining which treatments are effective. The threat of frost and freeze can last well into early May in southern New England (and some years even later based on last year’s frost event on May 18). Therefore, when plants start flushing new growth in mid-March, some level of frost injury is a serious concern. Winter burn on rhododendron, azalea, andromeda, mountain laurel, and holly appear to be minimal this spring due to the mild winter, but exceptions always exist. The foliar blight and premature leaf shedding late last summer on lilacs caused many plants to flush scattered new growth and blooms last fall. Some buds that broke last fall on these plants are now burned and desiccated. Saturation and flooding in heavy, poorly drained soils could be an issue for plants that don’t tolerate wet feet (boxwood, yew, and rhododendron). The resulting condition, known as edema, is likely to be a problem as the season begins. Symptoms include chlorotic areas of the upper leaf surface and dark-colored, callus-like blisters on the underside of the foliage. White pine weevil is active early in the growing season, feeding on the terminal shoot of eastern white pine and Norway spruce, among others. Spruce spider mite is active during mild periods of spring, so scouting and treatment of this pest should commence soon once the weather warms. Ticks have been very active this spring season so pay extra attention to these nefarious pests. Light-colored pants and permethrin applications to footwear can be very helpful.