UMASS Landscaping Update

Pioneer Valley (Amherst)

General Conditions: 

The glory of spring continues across the Pioneer Valley as we settle into May. There is so much new growth and color right now across the landscape that it’s almost impossible to keep up. Yet, if it wasn’t for the unseasonably warm temperatures in mid-April, we could be experiencing a late spring, with the persistence of cold nights in the 30s over this past reporting period.

April rainfall totals for the tri-counties were nothing to write home about, aside from a few locations. Totals ranged from 2.4–4.1” in Franklin County, 2.3–2.5” in Hampshire County, and 2.0–3.2” in Hampden County. The forecast at the time of writing calls for various showers in the extended forecast, so hopefully some respectable accumulations develop. With the showers last week and cool to mild temperatures, soil moisture remains okay in most locations. That said, new plantings should be closely monitored and watered as needed throughout the growing season. The small root zone of many transplanted trees can be shielded by the canopy from rainfall and overhead sprinklers, so be sure to hand check the soil.

Spring is often a very windy time in the Connecticut River Valley but aside from this past week (especially May 4-5) the spring winds have been less prominent this year. Mosquitoes and black flies are out, and the consensus is that tick populations are very high. Pollen levels continue to ramp up with oaks and hemlocks dispersing pollen, among many other trees and shrubs.Pioneer Valley (Amherst)

General Conditions:

The glory of spring continues across the Pioneer Valley as we settle into May. There is so much new growth and color right now across the landscape that it’s almost impossible to keep up. Yet, if it wasn’t for the unseasonably warm temperatures in mid-April, we could be experiencing a late spring, with the persistence of cold nights in the 30s over this past reporting period.

April rainfall totals for the tri-counties were nothing to write home about, aside from a few locations. Totals ranged from 2.4–4.1” in Franklin County, 2.3–2.5” in Hampshire County, and 2.0–3.2” in Hampden County. The forecast at the time of writing calls for various showers in the extended forecast, so hopefully some respectable accumulations develop. With the showers last week and cool to mild temperatures, soil moisture remains okay in most locations. That said, new plantings should be closely monitored and watered as needed throughout the growing season. The small root zone of many transplanted trees can be shielded by the canopy from rainfall and overhead sprinklers, so be sure to hand check the soil.

Spring is often a very windy time in the Connecticut River Valley but aside from this past week (especially May 4-5) the spring winds have been less prominent this year. Mosquitoes and black flies are out, and the consensus is that tick populations are very high. Pollen levels continue to ramp up with oaks and hemlocks dispersing pollen, among many other trees and shrubs.

Pests/Problems:

The scattered rain showers, cloud cover, and recent strong winds were ideal for spreading fungal spores over this past reporting period. Of note, the orange and gelatinous spore masses of cedar-quince rust (Gymnosporangium clavipes) and cedar-apple rust (Gymnosporangium juniperi-virginianae) have been abundant on eastern red-cedar (Juniperus virginiana) and other Juniperus hosts. While cedar-apple rust can occasionally be a problem, cedar-quince rust can be very damaging to both red-cedar/juniper and rosaceous hosts like serviceberry (Amelanchier) and hawthorn (Crataegus). While the cedar-apple rust pathogen produces galls on juniper needles, cedar-quince rust galls form on twigs and branches. When abundant, they girdle these tissues resulting in serious canopy dieback. The fungal cankering pathogen Diplodia can also be readily found on Juniperus with cedar-quince rust infections, furthering the dieback.

As noted last week, pine tip moth damage has been observed on several pines (Pinus) across Hampshire County this spring. Pictured here is damage from a pine tip moth larva (Rhyacionia sp.) on the developing candles of a mugo pine (P. mugo) on the UMass campus. Two species are problematic in the region, the European pine shoot moth (R. buoliana) and Nantucket pine tip moth (R. frustrana). Continue to scout hard and soft pines for this destructive pest. Small green caterpillars can be found on various deciduous hardwoods, although identifying them is much more challenging than finding them. Bruce spanworm (Operophtera bruceata) is a native moth that may be the culprit in some cases. In general, its presence does not warrant our time and energy but if numerous, it can be treated.

According to the UMass Fruit Team, the rainfall on May 6 will result in significant apple scab (Venturia inaequalis) infections across the area. We are also entering the period of fire blight (Erwinia amylovora) infections on apple (Malus) and pear (Pyrus).

Nick Brazee, Plant Pathologist, 

UMass Extension Plant Diagnostic Lab

, reporting from Amherst.