The Plant Doctor Is In

By Dr. Francis Gouin

A growing number of Bay Weekly readers are coming to the Thursday afternoon Deale Farmers Market with plants to be identified or with plant problems. I don’t mind interrupting sales of peaches to answer your questions. However, I find that I am not able to provide much assistance because many people bring only a leaf, a single flower or a photograph. Others try to describe the symptoms.
Plant identification requires more than a leaf or twig. Bring a branch so I can see how the leaves are arranged and whether they are simple, compound or doubly compound. Maple and oak leaves are simple leaves. Black locust or ash leaves are compound leaves, while the leaves of the Kentucky coffee tree are doubly compound. A leaflet from a compound or doubly compound leaf is not enough to make an identification.

What’s the Story Behind Small Acorns?

We have a beautiful 200-year-old willow oak tree. Usually it drops regular-sized acorns. This year, it’s been dropping tiny acorns no bigger than the end of my finger. They’re covering our porch. We were wondering if air pollution is the reason for this premature acorn dropping.

–Joyce Kirchner, Tuck Point

The reason why the willow oak is dropping tiny acorns is that its flowers have produced more acorns than the tree can carry. Thus the tree is thinning its acorn population. Heavy acorn production does not happen often. However, this spring there was a heavy pollen release and ideal conditions for flowers to be pollinated.
Oak trees behave similarly to persimmon trees. When the tree produces too many acorns, it thins itself so that the remaining acorns will grow larger. In horticultural terminology it is called pre-drop. There is nothing to worry about except stepping on the small acorns and falling. Walk with care.

Ask Dr. Gouin your questions at [email protected]. All questions will appear in Bay Weekly. Please include your name and address.

    Seeing how the leaves are arranged on the branch is also important in identifying plants. A gentleman recently presented me with a compound leaf and asked what it was. I concluded that it would be either an ash or a hickory. Had he brought a branch, I could have decided that it was an ash if the compound leaves were arranged opposite each other; if the compound leaves were alternately arranged on the branch, that would have identified it as a hickory.
   Another time a lady came with diseased-looking leaves taped to an envelope. She informed me that these were the worst leaves she could find on the plants. Plant problems are difficult to diagnose, and trying to provide good information from only one dead or dying leaf is impossible, especially if the problem is nutritional.
   Bring a branch that exhibits several symptoms and many leaves. Be prepared to answer questions such as how long has the plant been in its present location, how often you irrigate and for how long, whether the plant faces north, south, east or west, what kind of mulch you use and how often, what have you sprayed it with, what soil test results have you gotten.
   If you have problems with house plants, bring the plant and be prepared for me to remove it from its container. Many potted plant problems can be accurately diagnosed by examining roots.
   I enjoy talking plants and the challenges of trying to solve plant problems. There is no charge, but you must understand that customers come first.