Health tips for your evergreens

Q. My pine trees are turning yellow. Can you tell me what is wrong with them?

Wayne from Boardman

A. Your pine trees are probably fine. But we encourage gardeners to submit their samples when they do have a concern.

Pine trees, along with fir, spruce and arborvitae, are part of a group of trees called conifers, and they are evergreens. They are called evergreens because they retain their needles (leaves) throughout the winter. But evergreen doesn’t mean the needles last forever.

Yellowing of needles and needle drop can be alarming, but it is part of a natural process. The older interior needles turn yellow and drop off each fall. Some years it is more noticeable than others.

Depending on the species, needles remain on the tree for several years until they reach maturity. Once sufficient new growth has taken place at tips of branches, the older needles toward the center yellow and drop off, having served their purpose of photosynthesis.

Needles on white pine typically drop at the end of their second season. Red-pine needles persist until the fourth or fifth season.

If the yellowing is occurring on the interior of the plant, and the current season’s growth at the tips of the branches is healthy and normal, then the tree is probably fine. If new growth is weak or turning brown, this can indicate the tree has something going on with it – root problem or disease. If the outer needles are browning, it could be an indication the tree is not getting enough water.

Also, speaking of moisture, the best thing you can do for your pine trees, or any other evergreen you have, is to give them a deep soaking this fall to help them survive the winter in the best possible condition.

To learn more on the topic, go to: http://go.osu.edu/needledrop.

David Sprague, OSU Extension Master Gardener Volunteer, provided today’s answer. Call the office hotline at 330-533-5538 to submit your questions. Clinic hours are Mondays and Thursday from 9 a.m. to noon through October.