The Mystery of the Dying Tomatoes

About 30 years ago, I began to build up my garden with compost and leaves. Every few years, I would gather and put down about three feet of leaves to rot and be tilled into the 50-by-50-foot garden space. The garden now has a beautiful loamy soil. I have been planting with wonderful results for about 20 years.
    About six years ago, I collected the leaves and put them down but did not plant for two years. I gather the bags of leaves, mostly oak, from neighboring houses. Several mulched bags of grass were in the mix this time.
    When I next planted my garden in a six-by-30-foot area, all the plants, tomatoes and cucumbers withered and died over a 12-hour period. The plants had been in the ground for about three weeks and had begun to produce small vegetables.
    I immediately removed them. The University of Maryland Extension Service recommended I plant buckwheat and oats. This I did for two years in a row. It grew beautifully, and so did the weeds.
    This year I have once again planted the garden. In the very same area, all the vegetables withered and died over 12 hours.
    The garden has been tilled many, many times. This is the only area that has the problem. It has not spread to another section of the garden.
    Could I have gotten some chemical like Roundup in the collected bags? If that is the case, why has it not moved with all the tilling?
    I might add that the dead plants have perfectly healthy root systems, and there are no tunnels or holes from moles or voles.
    I am totally at a loss as to what is happening and as to what I can do to fix the problem. Any advice you can give would be greatly appreciated.
–Pat Fessler, Crownsville

The Bay Gardener’s Solution

    The problem is not Roundup. Glyphosate, as the Monsanto weed-killer is called, deteriorates into phosphorus once it enters the soil. It does not have weed control properties when it becomes a soil component.
    I suspect that the soil is infested with fusarium, which is a fungus, or possibly sodium or soluble salts. I suggest that you have the soil tested by A&L Eastern Agricultural Laboratories. Request the S3 test to include soluble salts and sodium. Submit one sample of soil from the affected area and a second soil sample from the surrounding area. Do not indicate crop or request recommendations. Each soil sample should include at least five core samples from each area. Air-dry the samples overnight before mailing them for fast results. Print submission form and instructions from the web page: www.al-labs-eastern.com.
    Have the lab send me the results at [email protected]. We’ll get to the bottom of this.