Josh Blanek

The next 45-60 days is an important time in maintenance of fruit and nut trees. February or March is the best time to do winter pruning of fruit and nut trees. However, be cautious when pruning in January or early February, as with drought, pruning stresses the tree, any form of stress make plants and trees more vulnerable to freeze injury, if a severe freeze should follow. Remember to always spray any wounds (cuts where you have pruned the tree) with tree pruning spray. Doing this immediately after you have pruned will help seal the cut, keeping insects & disease from entering the tree.

Another chore that needs to be taken care of is the dormant spray. Apply a dormant oil spray to fruit trees, pears and various landscape trees as well. Scale insects are a primary target of the oil spray. Scale are tiny scaling insects that can seriously injure or kill branches or entire tree. They attach themselves to twigs, limbs and major branches with smooth bark, and each insect seals itself under a protective covering. The covering are visible as scaly crust ranging from a dull grayish - white with San Jose scale (the most common scale on fruit trees) to snow white to a dull brown for other types of scale.

Scale insects tend to be especially serious problems on peaches, plums and stone fruits, as well as apples and pears. Numerous ornamental trees and shrubs are also affected.

Dormant oil spays are also applied to kill over-wintering eggs or various insects and mites. Phylloxera eggs are a primary target on pecan trees.

The dormant oil spray can be applied anytime the tree is fully dormant and before it has leafed out or began to bloom. Late winter is a better time than early winter because the scale insects weaken and become more vulnerable as winter progresses.

Good spray coverage is important since the primary mechanics of kill is suffocation by an oil film. Air sprays and other low volume sprays are not as good as handgun application.

Do not over apply dormant oil or tree injury may result. Heavy scale infiltration may require more than one dormant oil application for eradication. If a second oil spray is applied, wait at least three weeks after the first spray or until heavy rainfall has occurred.

Oil related injuries sometimes occur because of poor mixing in the spray tank so be sure that your spray tank has good agitation immediately before and during spraying.

For more information about properly pruning fruit & nut trees or applying dormant oil contact the Somervell County Extension Office at 254-897-2809 or email at j-blanek@tamu.edu or stop by 1405 Texas Drive.