Carefully select garden site

Q. Is the oak tree next to my garden causing my plants to die? I heard some trees are toxic to vegetable plants.

Richard M. from Youngstown

A. No, the oak tree is not killing the vegetable garden plants. But, the roots of this tree could be affecting the production levels of plants in the vegetable garden.

Tree roots are most likely the culprit in this situation and affect many gardens on small city lots where there is not a lot room for growing. The roots of many trees extend far away from the trunk, depending on the type of tree. The roots will uptake nutrients and moisture from the soil, leaving the vegetable garden in a deficit situation. Thus, the vegetable garden should be moved away from the tree. If this is not possible, container vegetable gardening might be the next best choice.

Vegetable garden sites should be chosen with care. Nearly all our typical vegetables grow in full sunlight. Eight to 10 hours a day is a must. Vegetables need well-drained soil that also is fertile and deep enough for the growing roots of crops you select. Having a water source will be a great advantage during nearly every growing season.

But there are trees that create toxicity problems for vegetable gardens. Black walnut and butternut are the two. Many vegetables will not grow within 50 feet of a black walnut tree. This includes tomatoes, eggplant, cabbage, peppers and others. This is because the tree produces a toxin called juglone. This toxin is present in leaves, bark, wood and, to a lesser extent, in the roots of these trees.

If you think you have a black walnut or butternut tree, be sure to get it properly identified. Having one is not the end of the world. There are plants that will grow around the tree. Squash, corn, beans and carrots are not affected by juglone. Many annuals, fruit trees and perennials are suited for these areas.

Read more details and find a list of plants not affected by black walnut here: http://go.osu.edu/blackwalnut.

Eric Barrett is OSU extension educator for agriculture and natural resources in Mahoning County. Call the office hot line at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays to submit your questions.