We normally do not think of January as being a good time to be out in the garden. Cold temperatures and dormant plants are two good reasons to stay indoors. However, these mild winter days have been ideal for getting an early start on spring pruning of trees.
Although pruning can be performed almost any time of the year, the dormant period is a good time to work on trees especially susceptible to weeping sap. So, grab the saw and sharpen your pruners, here are some tips for pruning your dormant trees.
Different species of trees vary in how easily and how much they ooze sap. Those that are most likely to bleed are silver, sugar, Amur, Norway, hedge maples, black walnut, pecan, birch, mulberry and Osage orange. Though bleeding may look as if it would cause considerable damage to the tree, this is not the case. Even if large amounts of sap are lost, there is no apparent long-term damage to the tree. However, many people find the appearance of this bleeding objectionable. Pruning during the winter when temperatures remain below freezing will help minimize sap flow.
There are varying degrees of pruning. Light pruning can thin the tree canopy and remove crossing branches that rub one another. Heading back removes only portions of limbs that may extend too far or are in the way when working around the tree. Major pruning can remove co-leaders or branches that hang down too low or are touching the house.
All pruning is executed the same way. For larger branches that require the use of a pruning saw, make three cuts. The first cut is made 12 to 16 inches out from the trunk of the tree. Start from the underside of the branch and saw up one-third of the way through. The second cut is made just past the first cut starting from the top and going all the way through the branch until it is removed. Make sure not to let the branch fall on power lines, fences or yourself. The third and final cut is made back at the trunk to remove the remaining stub.
The secret to good pruning is leaving the branch collar. The branch collar is the swollen area between the tree trunk and the branch you are removing. This area of tissue is fast growing and heals quickly. There is no need to apply any sort of pruning paint or sealant to these wounds.
Leaving the branch collar will allow the tree to heal completely.
For smaller branches, use pruning sheers and the same "branch collar" philosophy.
Pruning is an everyday occurrence in nature. Storms and heavy loads of ice or snow are constantly breaking or removing limbs. Pruning is just a controlled form of the natural. However, the difference is timing and making a good pruning cut.
-- Bruce Chladny is horticulture agent at K-State Research and Extension-Douglas County. For more information, call him at 843-7058 from 8 a.m. to 5 p.m. weekdays.