In selecting a sugarbush management strategy, consider both current tree
condition and your ability to tolerate unpredictable future stresses (like
drought) which could set decline in motion.
Evaluate factors which indicate
the risk of tree decline when
deciding how critical it is to adjust
management practices. Some are
Higher Risk of Tree Decline
Ridgetop, rocky ledge, or wet area
Thinned within the past 4 years
Some defoliated trees have died
Defoliated branches didn’t refoliate
Defoliated more than once
Trees have small or yellow leaves
Lower Risk of Tree Decline
Plenty of soil calcium
All tapholes close in 2 years
No increase in dead twigs
Full refoliation after defoliation
Low egg mass counts
Assess the likelihood of
defoliation by looking for forest tent
caterpillar egg masses or signs of
saddled prominent. Request a survey
or find out how to do it yourself.
If you decide the sugarbush can
be tapped, minimize wounds by
switching to 5/16" spouts while sticking to conservative tapping rates.
Be flexible when scheduling timber harvests. If trees have been
defoliated, delay thinning 1-3 years to minimize tress and to see which
trees remain healthiest.
Consider aerial spraying in 2007. If you may be interested in
participating in the state program, follow-up with the Vermont
Department of Forests, Parks, and Recreation as soon as possible. The
deadline to sign up is February 15th.
• The spray block must be actively tapped, at least 10 acres and
• The B.t. product, Foray, is a biological insecticide, but not
certified organic at this time.
• The cost to landowners will be unknown until details are
finalized. The expected range is $15-30/acre. We do not
anticipate any cost share.
• Spray blocks need to conform to federal and state public safety
and environmental requirements.
• Some defoliation will occur before spraying. Heavier
defoliation will occur if spraying is delayed by weather or
• Some trees in the block may be missed by the spray plane.
For additional assistance, contact the Vermont Forestry
Division District Office nearest you, or seek assistance
from your County Forester.
Vermont Forestry Division District Offices:
Springfield (802) 885-8855
Pittsford (802) 483-2314
Essex Junction (802) 879-6565
Barre (802) 476-0170
Saint Johnsbury (802) 751-0110
Vermont Forestry Division, December 2006