My squash, cucumber, beet and Swiss chard plants appear to be undersized. Five years ago we had a very large tree adjacent to the garden cut down. When I dig in the garden I still find roots. Could there be a problem with the soil because of the tree roots? Would a soil test tell me anything?
A soil test is always a helpful tool in establishing and managing a garden or landscape. Contact your local University Extension office. If the tree you removed was a black walnut, it could be the problem. All parts, including the roots or black walnuts contain juglone, a substance toxic to many plants. It can take 5 to 10 years for the roots to decompose and lose their toxicity. If this is the case – patience or moving the garden is the solution. If the tree wasn’t a black walnut the plants may be lacking nutrients temporary tied up during the decomposition of the old roots. A little additional nitrogen fertilizer will help compensate for this temporary shortage. Don’t overdo the nitrogen or you will have large plants with no roots or fruits to eat. Follow your soil test recommendations to improve the health and productivity of your garden.