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People tend to forget about their trees during the winter months. We assume that because the trees are dormant, little or no care is necessary or even possible.

Actually, the winter months can, and should be utilized by those of us who are concerned with the health of our trees. While dormant pruning provides the same benefits as does pruning during other times of the year, it has definite advantages in certain situations as in the case of maintenance pruning of mature trees.

The goal of pruning mature trees is to maintain their structure and form by removing dead branches. Thinning large branches will reduce the weight and wind resistance of the tree and allow light penetration to maintain inner growth. Remember, however, pruning should always be performed sparingly.

Over-pruning is extremely harmful because without enough leaves, a tree cannot gather and process enough sunlight to survive. When a portion of a tree' s canopy is removed during the dormant season, we often notice an increase in new growth from the remaining branches. This occurs because the energy stored in the roots and branches is channeled to fewer growth points the following spring. Since the same amount of energy is spread among fewer growth points, each new shoot grows a little more than it would have if the tree had not been pruned.

There are several types of pruning. One type is called crown cleaning. This is the removal of dead, dying, diseased or weakly attached branches and water sprouts from the tree's crown. Crown thinning is where you remove some branches to increase light penetration and air movement. Crown raising is the removal of lower branches of a tree to provide clearance for buildings, vehicles and pedestrians.

Proper pruning cuts do not injure the branch bark ridge or the branch collar. The branch bark ridge is the raised line of bark that forms between the branch and the trunk. The branch bark ridge lengthens outward as the branch and trunk grow in diameter.

The branch collar is the living, swollen trunk tissue that surrounds the base of a branch. The size of the branch collar and branch bark ridge varies between individual trees and tree species.

The branch bark ridge and branch collar are involved with the natural defense mechanism of a tree. Flush cuts made inside the ridge and collar, destroy the tissue of the tree that defends against decay. Proper pruning cuts are made as close to the branch bark ridge and branch collar as possible, without removing or injuring it.

If the pruning cut is made too far away from the branch collar, a stub will remain. Stubs provide a perfect energy source for insects and disease organisms.

Proper pruning is one of the best things a person can do for their trees.

Improper pruning is one of the worst. A healthy tree will seal itself and wound dressing may actually interfere with this process.

Mark your calendars now for the 8th annual Chisago County Master Gardener Spring Gardening Bonanza. This year' s event theme is " Get the Dirt" and will be held Saturday, March 4, at the Abundant Life Church, 4359 392nd Street, North Branch, from 8:30 a.m.3 p.m. Registration brochures will be available around the end of January.

We will again be selling bare root blueberry, strawberry, raspberry, grape and asparagus plants that are hardy to zone 3. The plant order forms will be mailed along with the Bonanza brochure.

We will not be doing classes at Bonanza on growing these fruit plants BUT classes will be offered as part of a separate weekly series this spring, which will also include some vegetable gardening topics. The schedule for the ' Spring Gardening Series--Growing Edibles' will be available at Bonanza.

The voicemail is available all year long at 651-674-4417. Maybe you have a houseplant problem or a question about something you saw in a gardening catalog. During office hours ask for the Master Gardener voicemail, after hours, select ext. 18.

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