Gardening matter, early and late blight in tomatoes - Ask Extension
I am an avid gardener. I grow cucumbers, string beans, squash, onions, peppers and more but my main crop is tomatoes of which I plant around 50 plant...
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Gardening matter, early and late blight in tomatoes #855633
Asked November 21, 2023, 2:34 PM EST
I am an avid gardener. I grow cucumbers, string beans, squash, onions, peppers and more but my main crop is tomatoes of which I plant around 50 plants each year, some years more. All are used for our family and friends. I grow the plants from seeds, rotate crops each year on a 100' by 70' area in my back yard. I also remove the plants are seasons end. The garden has continuously been in use since 1968 and I took it over in 2002. 30+ years ago I recall my father saying the potatoes he planted got a disease which could affect the tomatoes. When I started in 2002 I would have tomatoes until frost. However, in the last 10 years I most often get early blight and the tomatoes are gone by early to mid September. This past season I tilled up a portion of the yard which had not been used as a garden for 20 years and still got the blight in the tomatoes I planted there. I just sent a soil sample to your lab and should have the results by the end of next week. I included a note with this information and they said to contact you. Any suggestions???? The other crop I have problems with is squash, the plants begin to bear fruit and suddenly die.
Howard County Maryland
Expert Response
There are a couple of things that could be happening here. A soil test is a good start for analyzing and resolving your problems. I am assuming that you are doing a soil test ($17) at our soil lab in Newark and not a pathology test. If you have any tomato plants still in the ground, you should dig up one of the affected ones including root mass, bag it & send it in to testing for nematodes and root disease with our lab. Just in case you still have one available I have attached the form. The plant and form can be dropped off at your local Extension Office. They are located by county and can be found here:
https://www.udel.edu/academics/colleges/canr/cooperative-extension/directory-contacts/
There are several reasons your tomatoes can be getting recurring early blight. You mentioned you start them from seeds and the plants in the new plot also got early blight. Are you using seed from prior year tomatoes? if so, the early blight disease is present in the seed material and will be passed on to the new plants. You should replace your seeds with fresh, blight resistant varieties. Also make sure to sterilize your seed starting materials and potting area with a 10% bleach solution.
If you have a nematode problem with your tomatoes, plant them with marigolds which deter nematodes. At the end of the season when you remove your finished tomato plants you can turn under the stems of the marigold for organic matter and future protection.
Crop rotation is very important and plants in the same family should be rotated out of the area at least on a 3 year rotation, especially if you have had early blight. Here are two publication that discuss crop rotation by plant family and diseases of tomatoes. The section on management of Early Blight is excellent.
Tomato Diseases & Disorders | Home & Garden Information Center
Plant Rotation in the Garden Based on Plant Families
From your description, it sound like your squash vines are being affected by Squash Vine Borers. Following is a publication that discusses squash vine borers and squash bugs. You'll know by the photos in the publication which pest is affecting your crops. They both have management practices listed,. Clean up is key at the end of the season & again crop rotation. The adults overwinter in the soil and if you plant your squash in the same area they are more easily affected.
Squash Vine Borer and Squash Bug | Entomology
If you determine squash vine borer is your problem, try planting your squash 6 weeks apart. The second crop should be unaffected as the adult will no longer be flying, although your harvest may be reduced if we have an early frost.
I hope this helps and if you have any further questions after you receive your soil test results do not hesitate to contact us.
https://www.udel.edu/academics/colleges/canr/cooperative-extension/directory-contacts/
There are several reasons your tomatoes can be getting recurring early blight. You mentioned you start them from seeds and the plants in the new plot also got early blight. Are you using seed from prior year tomatoes? if so, the early blight disease is present in the seed material and will be passed on to the new plants. You should replace your seeds with fresh, blight resistant varieties. Also make sure to sterilize your seed starting materials and potting area with a 10% bleach solution.
If you have a nematode problem with your tomatoes, plant them with marigolds which deter nematodes. At the end of the season when you remove your finished tomato plants you can turn under the stems of the marigold for organic matter and future protection.
Crop rotation is very important and plants in the same family should be rotated out of the area at least on a 3 year rotation, especially if you have had early blight. Here are two publication that discuss crop rotation by plant family and diseases of tomatoes. The section on management of Early Blight is excellent.
Tomato Diseases & Disorders | Home & Garden Information Center
Plant Rotation in the Garden Based on Plant Families
From your description, it sound like your squash vines are being affected by Squash Vine Borers. Following is a publication that discusses squash vine borers and squash bugs. You'll know by the photos in the publication which pest is affecting your crops. They both have management practices listed,. Clean up is key at the end of the season & again crop rotation. The adults overwinter in the soil and if you plant your squash in the same area they are more easily affected.
Squash Vine Borer and Squash Bug | Entomology
If you determine squash vine borer is your problem, try planting your squash 6 weeks apart. The second crop should be unaffected as the adult will no longer be flying, although your harvest may be reduced if we have an early frost.
I hope this helps and if you have any further questions after you receive your soil test results do not hesitate to contact us.
