Late Fall & Winter Tree Health Tips

The Hailey Tree Committee is offering some tips for late fall and winter tree health:

  • Stop fertilizing plants 6 weeks before the first frost.
  • Deep water evergreens before the ground freezes, 12-18” deep.
  • After the ground freezes, apply a 3” layer of mulch around the tree, but several inches (3 to 6 inches) from the tree, conserving moisture and insulating roots until covered by snow. Avoid a “volcano” pile at the tree trunk, which will trap moisture and cause decay of the trunk. The
    mulch can be spread all the way out to the drip line of the tree, where the roots gather the most
  • Protect newly planted and thin barked trees from sunscald with white tree guards or tree wrap, or paint trunk with diluted white latex paint.
  • Use hardware cloth to protect bottoms of trees from gnawing animals. Staking around trees can reduce browsing damage.
  • Shovel or blow snow before using any salt near trees. Avoid sodium chloride, use magnesium chloride or calcium chloride when possible.
  • Be careful installing holiday lights, installing strands up and down and not around small branches, which can damage next year’s buds. Remove lights BEFORE buds break in the spring.
  • Prune in late winter or spring, removing crossing, broken branches and co-dominant stems.
  • Before bud break in spring, use dormant oils to reduce insects such as aphids. The term ‘dormant’ refers to the time of year the oils are applied. These oils are highly refined lightweight horticultural oils of petroleum or vegetable base.