Thanks for your question.  I will try to help you.  I don't know yet if blight is the correct term for what's happening.  It appears that this same condition has occurred in past years.  Have you always planted your tomatoes in the same area?  If so, that would suggest that there may be something in the soil.

Looking forward to hearing back from you.  Thanks for consulting us.

Thanks again for the question.

In looking at your pictures, I think that the most striking feature is that there seems to be a mixture of healthy-looking leaves and yellow leaves. If the cause of this condition was due to something in the soil (e.g., nutrient deficiency), it would be reasonable to expect that all the leaves would be showing yellowing. I believe that your initial suspicion of tomato blight is correct. More specifically, it may be Early Blight (Alternaria). It is one of the most common tomato diseases in Minnesota. It usually begins with yellow leaves near the bottom of the plant. The oldest leaves are there. It then spreads slowly upwards through the tomato. It is caused by one or more species of fungi within the genus Alternaria. See the following for further information. In some of these sites, note that a black spot on a leaf surrounded by a yellow halo is a characteristic symptom. I did not detect these in your pictures, which makes me slightly question my diagnosis of Alternaria. Please look over the plants to see if such are present. These sites also contain information regarding remedial and preventative actions including the use of fungicides.

https://extension.umn.edu/disease-management/early-blight-tomato-and-potato

https://en.wikipedia.org/wiki/Alternaria_solani

https://content.ces.ncsu.edu/early-blight-of-tomato

https://extension.umn.edu/plant-diseases/tomato-leaf-spot-diseases

https://www.uvm.edu/extension/news/tomato-leaf-spot-diseases

I’m sending this in the absence of hearing back from your regarding planting location. Regardless of what that answer is, I suggest that you plant tomatoes in a different location for 2026 and well away from the 2025 location.

Lastly, you may want to consider sending in plant samples to a plant diagnostic laboratory. Excellent ones exist at both the University of Minnesota and the University of Wisconsin. That would be the only way to get final closure as to what is going on with your tomatoes. See:

https://pdc.umn.edu/

https://pddc.wisc.edu/clinic-overview/

Good luck. Get back to us if you have any further questions. Thanks for using our forum.

Thanks for the recent information.

I’m thinking that perhaps you should try growing Early Blight (Alternaria) resistant tomatoes in 2026 See:

https://www.vegetables.cornell.edu/pest-management/disease-factsheets/disease-resistant-vegetable-varieties/disease-resistant-tomato-varieties/

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/fungal-spots/early-blight-of-tomato

https://growingformarket.com/articles/understanding-early-blight - :~:text=Preventing early blight&text=Valentine, Plum Regal, and Juliet,/paste types – are resistant.

https://savvygardening.com/disease-resistant-tomatoes/

If you go down this route, obtaining specific varieties may present a challenge. This is a task for spring 2026. Certainly, call around various gardening centers in the Metro Area at this time to see if this might be something they could order for 2026. You may have to go online to find something.

For sure, plant your tomatoes in 2026 in a different location from 2025.

At this point, I don’t see any need for soil treatments. In fact, it would be difficult to determine what, if anything, might be wrong with your soils.

Good luck. Please get back to us with any additional questions.

Thanks for your thoughts.

When I first looked at your pictures, fusarium wilt was one possibility that I considered. I decided against it because this disease is a very dramatic one in tomatoes and leads to significant wilting. Often this wilting is confined to just one side of the plant. I did not observe this in the pictures.

One of the significant symptoms of fusarium wilt is the appearance of brown streaks just under the stem. From your pictures I was unable to determine if this browning is present. However, it would be very easy for you to check for this symptom. Perhaps this might be something you could do? At the first site below, there is a great picture showing this stem browning:

https://extension.umd.edu/resource/fusarium-wilt-tomatoes-home-garden/

https://content.ces.ncsu.edu/fusarium-wilt-of-tomato

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/cankers/fusarium-wilt-of-tomato

https://ucanr.edu/blog/hort-coco-uc-master-gardener-program-contra-costa/article/verticillium-and-fusarium-wilt

I still will abide by my diagnosis of early blight. However, please go through the all the sites I’ve provided you and make your own decision. Again keep in mind what I previously suggested: the use of a plant disease diagnostic clinic. Good luck. Keep asking your questions!!

I am still considering your thoughts about fusarium wilt in your Amish Paste tomatoes. It turns out that it is very common in such tomatoes. Early blight is also quite common. See:

https://www.smartgardener.com/plants/112-tomato-amish-paste/diseases/740-fusarium-wilt - :~:text=This fungal disease most often,and water to the leaves.

Good luck in beating whatever is messing with your tomatoes.

Glad to have been of assistance.  Thanks again for consulting with us.