Early and Late Blight on tomato crop every year

Asked March 9, 2016, 11:23 AM EST

I get early and late blight on tomato crop every year - with the exception of my first year. I have been gardening for 6 years. I have tried everything except spraying. I have young children who eat right out the garden - too afraid to spray or use any type of chemical. Last year I rotated the crops and moved my tomato plants to the other side of the house (huge disappointment) to give the soil a break. This year I am starting my tomatoes from seeds - purchased blight resistant varieties. Before I plant the tomato plants my garden - should I dispose of the soil and start new? If I dispose of the soil should I remove it from my property - or can I spread it on my property? Opinion on using black mats when planting to prevent splashing? Thanks so much.

Blair County Pennsylvania

1 Response

Tomato blight is carried over from season to season in plant debris that drops to the ground. The blight is host specific, so the spores don't survive except on debris from the host plant. However, the blight spores can also travel in the air and infect your plants if the source is in your neighborhood.

If you don't have a raised bed garden, I would make a raised tomato bed and add some top soil and then mulch. You don't want rain water to splash soil on the plant leaves. Then space your plants out to allow lots of air movement. Prune off the lower leaves and keep the plant out of contact with the soil. Since blights are a form of water mold, they need wet leaves to begin their infection process. Only water with soaker hoses that wet the ground but not the leaves. Inspect your plants regularly and immediately remove any plant parts that show signs of infection. Those signs mean the plant is infected and is ready to make spores, You want to cut off the spore making cycle asap. All plant debris you remove from this year and prior years must be burned or put in the garbage for collection. As long as the blight has host tissue, it can live in a dormant form. It cannot survive in the soil without host tissue.
Here is a link to an excellent article on early blight of tomato and potato. Here is a link to a publication by Cornell University on late blight. Having had both in my garden, I feel your pain.