I'm at my wit's end over this. When I lived in NY, I do not recall tomatoes ever getting blight at our house. When I lived for a decade in IL, I dealt with blight one year. It wiped out everything eventually, but the next year was back to normal.

But since moving to MS it's an every year thing. If I plant 40 plants I MIGHT get enough tomatoes to make a dozen pints of sauce before the plants are dead from blight.

Usually, my tomatoes get the first signs of blight, before they ever get the first blossom! They definitely have blight long before a tomato even dreams of turning red. And the past three years I've bought hybrids that are supposed to be blight resistant, which has had zero effect.... they still get blight.

I heard that it lives in the ground, so this year I spent a small fortune to plant all my plants in containers on the opposite side of the yard from my normal garden. 3 weeks after transplant.... they all had blight.

I'm about to say screw growing tomatoes at all!

It's our humidity, no way around it.

I prune everything to a foot or so above the ground. No lower limbs. Pine straw or plastic mulch helps. But I have best luck with weekly sprays of Maneb.

Tried plastic mulch the past few years and it didn't seem to help at all.

Guessing Maneb is a type of fungicide. I have one but not sure of the name.

When do you start spraying them?

How are the neighbors dealing with it? There's got to be some one around there growing tomatoes. Maybe get a GOOD soil test kit. They're not that high.
I tested my soil a couple years ago and found out my garden soil was short on everything. Just dirt with a lack of all nutrients. I've ask people in the know on tomato blight and they say the same thing; lack of calcium.

Do yo have a county farm agent you could call or a University outreach center?

We get blight in Northern Michigan. Some years more so than others. Pruning, rotation, sulpher based sprays. I am also spraying baking soda for the second year with good results, will continue with soda sprays for another year or two to confirm it helps. Another important thing is plant spacing, went from 2 foot to 4 foot spacing. Plants get bigger and are more productive.
A few drops of Dawn dish soap in every spray ensures good contact of spray. Early morning sunshine and air movement is huge, watch the morning sun, grow tomatoes where the early sun can dry plants.Good luck!

I’ve had it bad spray with copper sulfate solution once a week helps but this really helped me out was when I covered my garden with black plastic for 2 solid years and let the soil cook , I have enough ground that I moved the garden now I cover it after the season and let it solarize until next year

I prune 20-24" up from the ground. I want absolutely no leaves anywhere close to the soil. I get less blight now that I use the ground cover too. I still get some, but nowhere near as much.

Never seen it the many years of raising tomatoes. I believe you got some great advice though on things that is very helpful for a health productive plant.

Good ideas

I use "Mancozeb" for my grapes. Last year, When I was done spraying the grapes, I figured what the heck, and gave the tomato plants a squirt. I did this for the first month or so before they really started fruiting. 2TBS/Gallon of water. We had the best harvest ever last year. I used to have blight problems just like you. I'm not 100% sure that Mancozeb was the reason but I had no blight. I'm hitting them again this year and so far, they look great. Here

Copper fungicide as stated above and I add a bit of neem oil. Started here 3 years ago. Moved plants, garden site etc. no help. The spray will keep it in check enough for a decent crop. Fwiw. Heirloom tomatoes we planted this year seem to be a bit more resistant.

Start your first spraying two weeks after planting and two week intervals after that.

Soaker hoses are your friend in the garden. Avoid sprinklers that splash soil and create damp wet air. Airflow is important. I'm bad to try to cram as much as I can into the space available. That works with corn and beans but not tomatoes. I've learned that I need at least a plants worth of space between plants. And play the wind so they can catch whatever breeze you may get.

Why i quit fooling with it, this damp humid climate down here EVERYTHING rots on the vine. If isn't blight it's a hard rain in the middle of the day soaking everything then the sun pops back out and the fruit's are sun burnt. Then comes the cut worms over night, easier to just stop at the stand on the side of the road. lol

A variety called Better Boy seems to resist blight here.

I believe Finster uses a similar fungicide that I do. Manzate once a week before harvest. Then manzate and Bravo after harvest starts. I'll throw in some copper once a month. Later on in the very heat of the summer, you need to watch for spider mites. You would think you have blight, but actually spider mites. Would have to add in a miticide. There is a new tomato called compari (sp) that is pretty much disease free. Size of a large golf ball but very tasty.

I have had blight a few year, two out of the last 12 were really bad. I plant clebrity and a couple other varities that are rated for fair to good resistance to several diseases. I put down 18 inch wide landscape cloth for some splashing but mostly weed control. When I plant I lay the plant in a fungicide solution before planting. I spray about every 5-7 days for at least a month. I see a couple leaves turning white and today I will prune those. I have not done the pruning to the extant that many of you have, but that is a good option, especially for the undeterminate vairieties. We have heavy soil and are mixing in a lot of composte so our soils will hold a lot of organisms. I have rotated, but not as many years as some of you have. Our site is in open sun and the wind helps keep the humidity lown too.

Bryce