The last few years I’ve grown tomatoes, they’ve come down with the blight (kind of the tomato equivalent of bubonic plague). What to do?
I had dinner with some Italian friends, and we had a rousing discussion of how to prevent/cure tomato blight, which dissolved into conflicting “true stories” involving home remedies and nylon stockings.
- Grow tomatoes in a warm, dry, sunny area. If you have had blight previously, move to a different area if possible, or replace the upper soil layer since “oospores” will carry over in soil.
- Water only underneath the plants, not the leaves or fruit. Drip irrigation is preferable to watering with a hose, to reduce water splash. Don’t overfertilize or overwater.
- Grow on a light sandy soil if possible or cover soil with a white plastic mulch to increase soil and air temperatures around the plants and reduce humidity.
- Growing plants under an overhang* or a clear plastic shelter will help prevent spores from being deposited on plants by wind and rain. But plants must be covered before infection has occured. Covering the plants after they are infected may raise humidity and make the disease worse.
*Update July 25, 2010: I now grow my tomatoes under an overhang and use drip irrigation. I’ve never had late blight again!
Heavy Petal is on vacation until August 9. This article originally posted September 29, 2005.