Fungal infection in raised bed garden box - Ask Extension
Is there a fungicide I can add to my garden box soil now or in early spring to get rid of what I believe is a fungal infection that has made my tomato...
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Fungal infection in raised bed garden box #889756
Asked November 12, 2024, 11:41 PM EST
Is there a fungicide I can add to my garden box soil now or in early spring to get rid of what I believe is a fungal infection that has made my tomatoes do poorly 2 years in a row? The disease starts with the bottom leaves looking unhealthy/yellowish then brown spots develo and the leaves wilt. I remove the diseased leaves but the brown spots and unhealthy leaves spread upwards. The infected plant doesn’t grows well. I ended up planting peas this year after my tomato starts developed brown spots on the leaves and the peas did OK. Do I have to completely remove and replace the soil? I know I could solarize the garden box this summer, but it’s the only garden box I have. Is there any other solution?
Multnomah County Oregon
Expert Response
Thank you for your question, Lisa. Unfortunately, there are over 40 diseases, both fungal and bacterial, which effect tomatoes, about half of which cause symptoms such as you describe (https://pnwhandbooks.org/plantdisease/host-and-disease-descriptions?title=tomato). We are unable to diagnose which disease your plants have without photos and/or a lab examination. It is not advisable to use a pesticide without knowing the problem, and replacing the soil won't help if the plant was diseased before you got it, or it is an airborne disease.
Peas are in a different family, and less susceptible to most of the described problems. If you still have some diseased plant tissue, you can send it to the OSU Plant Clinic for examination. https://bpp.oregonstate.edu/plant-clinic/submit-sample/how-submit-plant-materials
I suggest that you grow tomatoes in a different container next year, with "fresh" potting soil (that is sterilized) to see if the symptoms recur. But, if the disease comes in with the seedlings, you'll have to use the correct treatment. Some fungi are helpful in breaking down organic material to "re-use" the nutrients. I hope this is helpful. Good luck!
Peas are in a different family, and less susceptible to most of the described problems. If you still have some diseased plant tissue, you can send it to the OSU Plant Clinic for examination. https://bpp.oregonstate.edu/plant-clinic/submit-sample/how-submit-plant-materials
I suggest that you grow tomatoes in a different container next year, with "fresh" potting soil (that is sterilized) to see if the symptoms recur. But, if the disease comes in with the seedlings, you'll have to use the correct treatment. Some fungi are helpful in breaking down organic material to "re-use" the nutrients. I hope this is helpful. Good luck!
