tomato fungus in raised bed

Asked September 3, 2020, 2:26 PM EDT

Hi- for the 2nd year in a row, I seem to have some kind of fungus or mildew on my raised bed tomatoes. I plant them 2 feet apart using the square foot gardening method. Is there an organic way to treat the soil before I plant next year, and should I treat in the spring? I will likely add compost to the soil in the spring as well. Thanks

Baltimore Maryland

1 Response

It is a rare Maryland tomato gardener that doesn't experience some sort of disease, but thankfully they can be managed pretty well. We'd guess you may be dealing with either Early Blight or Septoria leaf spot.
One of the most common tomato diseases is Early Blight.
Here is our page on it: https://extension.umd.edu/hgic/topics/early-blight-vegetables

Septoria leaf spot is covered here: https://extension.umd.edu/hgic/topics/septoria-leaf-spot-vegetables
Both pages cover best management practices to slow the disease, and sanitation and clean up at the end of the season, with removal of the residues out of the landscape is recommended. (You don't have to treat soil which is not practical).
As in any plant diseases, the more sunlight and air circulation that you can provide is helpful. Next season, thin out foliage by removing lower leaf branches and pinching or pruning out excess suckers ( that jut out at stem/branch junctions).

Here is our page on Tomatoes: https://extension.umd.edu/hgic/topics/tomatoes
and a recent post from our MarylandGrows blog as well:
https://marylandgrows.umd.edu/2020/06/19/tomato-tips-2020/


Christine