It’s a nasty disease that got all the organic tomato growers in our area last summer. It gets every last plant.
The topic of tomato blight came up in the comments of this post about natural pest control.
Rene, the author of that post, had this to say:
If it is only one plant that has blight I would pull it up. Blight spreads really easily through touch. This could be your hands, or insects going from one plant to another. After touching the plant that is affected, make sure to wash your hands really well with soap and water so that it does not spread further. If it is on several plants, you will want to remove all of the leaves and branches that are affected making sure to not touch any other areas of the plant or drop the pieces that you remove. Really the best way to prevent it is before you plant, with powdered milk or crushed eggshells.
You can try to place powdered milk into the soil around the plant, just make sure not to disturb the roots. Also when you water those plants, just water the soil not the plant if possible. (I know that it rains, so this won’t be a real fix.) You can also try spraying your plant with compost water. What this is is really good compost that is in non-chlorinated water. (Just leave your water out for at least 24 hours to remove the chlorine.) The compost will have good microbes in it to help fight the blight naturally. Blight is difficult to get rid of though.
Next year, you will want to plant your tomatoes in a different location since there will still be blight in your soil in that area. You can just prepare the soil next year the way that I described in the post above to prevent blight from forming.
I also came across a couple of sources to help solve the problem, although I admit I haven’t had to use any of them myself.
The first is from one of Jerry Baker’s books that I mentioned checking out at the library when I first started gardening. It’s a preventative tip (so bookmark it for next year!):
Mix 1 part skim milk and 9 parts water and apply with a hand-held squirt bottle to the point of run-off in the early part of the summer to discourage diseases from getting started.
You can also take steps to prevent blight when planting your tomatoes.
Our contributor Haley has an awesome post on the many varieties of tomatoes available, plus a simple tomato and mint salad recipe!
Did you know that essential oils have a shelf life?
Katie here, popping in to tell you that those essential oils that have been sitting in your cabinet for a couple years and are still half full may have expired. Read more about what I learned when researching this topic, and you can even have the handy printable I made to help me remember how long which oils last.
Prevent Blight for Next Year’s Tomatoes!
If you’ve already got blight, here’s how Baker would get rid of it for next year’s tomatoes:
Spray the garden in late fall and early spring with: 2 Tbs bleach + 2 Tbs baby shampoo in a gallon of water. This covers 100 sq. ft. During the growing season, spray plants every two weeks with an all-purpose liquid fruit tree spray following package instructions.
I don’t know if one can find organic fruit tree spray though, but this sounds like a serious problem!
Here’s another way to fix your soil for next year from Backyard Living Magazine, March/April 2007:
“Once infected, tomatoes can’t be helped. The key is solarizing the soil to kill the bacteria before they get to the plants. As soon as you can work the soil, turn the entire bed to a depth of 6″, then level and smooth it out. Dig a 4-6″ deep trench around the whole bed and thoroughly soak the soil by slowly running a sprinkler over it for several hours. Cover the bed with a clear, heavy plastic painter’s drop cloth. Lay the edges of it in the trench and cover with soil to keep heat from escaping. The sun should heat the area for at least 6 weeks. The longer you leave the cover in place, the better.”
Check out these FREE gardening classes from Craftsy – pause and replay to catch all the tips. Once you sign up you can “attend” at any time!
I have that page because I keep a gardening binder. I tear out anything of interest, and in the winter, I organize all the pages into sections like “vegetables” “starting seeds” “flowering plants” and “houseplants.” Tomatoes have their own section! Complicated little buggers.
Want to Dig into Gardening? 
I want you to imagine increasing your harvest with proven techniques that won’t consume your time.
I also want you to imagine decreasing disease and pests with time-honored crop rotation and companion planting.
Check out my dear friend Melissa’s Organic Gardening Workshop. Melissa is a 5th generation homesteader with 20 years of experience growing her own food. In fact, she raises more than half of her family’s fruits and vegetables with a day job and on only a half-acre.
She has got an amazing special going on to help you learn:
- how to naturally build healthy and organic soil at home with composting and/or cover crops
- vertical gardening to grow MORE in the same amount of space
- natural pest and disease treatment options that WORK
- how to easily work permaculture techniques into your property to take advantage of nature’s design for your food
- how to use cold frames in the spring and fall to increase your ability to grow food longer & extend your growing season (if not all year long)
- easy seed starting with vigorous seedlings that not only sprout but thrive when you plant them outdoors
- how to evaluate YOUR property and growing space to its best advantage so you don’t waste precious time, resources, and energy having to replant or move beds
Ready to get your hands dirty? Here are some more Gardening Posts from KS:
Lazy Gardening 101
Gardening Permaculture Techniques for Containers
Make Effortless Gardening a Reality
Garden Planting in Barrels
Organic Gardening: How to Get Rid of Tomato Blight
Easy Fall Garden
Organic Gardening: Why we Should Avoid Pesticides
How to Plant the Best Tomatoes
Kill Weeds Organically
Compost Gardening
Organic Gardening: Natural Pest Control
Your Guide to Tomato Types and Colors
Katie Kimball, CSME is a trusted educator and author of 8 real food cookbooks. She is passionate about researching natural remedies and making healthy cooking easier for busy families. She’s been featured on media outlets like ABC, NBC and First for Women magazine as well as contributing regularly on the FOX Network. 
A mom of 4 kids from Michigan, she is a Certified Stress Mastery Educator and member of the American Institute of Stress.
Kathryn says
I just planted my new tomato plant in soil from my last year’s tomato plant, which had blight. I just realized my mistake. Is it now contaminated?
Carolyn @ Kitchen Stewardship says
Oh no! From everything I’ve read, it probably is. Blight stays in the soil for a few years. I don’t know if you can remove it and save the plant if it’s only been planted for a day or two. I’d try to save it by removing the plant, shaking off as much soil as possible, and replanting in a pot so as to not spread blight to another garden bed and then see what happens.
Jessica says
If I move my tomatoes to a different location can I plant other non nightshade vegetables there??
Carolyn @ Kitchen Stewardship says
Hi Jessica, I’m no expert on this, but I did some looking online and it looks like tomato blight can spread to some other non-nightshade plants as well. The general consensus that I found on gardening sites was to take steps to treat the soil and plant your nightshades somewhere else and non-nightshades in the blighted spot. So yes you can plant non-nightshades, but you’ll still want to treat the soil thoroughly first. I hope that helps!
Alicia says
The article said to use bleach and baby shampoo at bed of year to kill the “bacteria”. I just want to point out to the author that blight is caused by fungus NOT bacteria!
Carolyn @ Kitchen Stewardship says
Thanks for catching that Alicia!
Nona says
I have the late blight and I did plant the small tomato plants in eggshell in there dug holes. I bought small plants already started. When I dug the hole I put in some eggshells. I used to put in compost as well but thought I would not do it this year just in case the blight was carried in the compost. I laid black heavy plastic on the ground and made small holes in it to plant the small plants. Didn’t help other than having no weeds. I have had this problem for many years and have tried everything but the powdered milk treatment. Our season (Northern Ontario, Canada) is too short to solarize the ground for close to 2 months as our growing season is only about 4 months long.
Stephanie says
Are the tomatoes still edible though if the plant has blight?
Barb says
I guess they are I just bought some from my local organic farm. Didn’t see it till I got home.
Jessica via Facebook says
Kitchen Stewardship that’s amazing about the lightening!!! We’ve been having some really awesome thriving tomato plants AND a ton of storms! 😀 my plants always perk up after a good rain storm too, even though I have been watering them anyway (well water not city)
We alternate the use of fast acting lime w/ fertilizer. one week we lime, then 3 weeks later we fertilize. Back and forth. It works out very very well! 😀
Sherry says
hey wondering do you put the fast acting lime at the roots of your tomato plants? I want to try this.
chuck patch says
i do doesn’t hurt them at all
via Facebook says
Good luck Caitlin Wright-Villasenor – if you’ve had thunderstorms, the lightning actually helps tomatoes to grow huge like that! So interesting – they grab nitrogen from the lightning…
Spencer says
Nitrogen is in the air which is 80% Nitrogen, not in lightning. Lightning causes the Nitrogen to mix with the rain water.
Caitlin via Facebook says
no picking yet i actually just got my first 2 tiny little green balls. but the plants are almost as tall as me for sure! They are insanely covered in flowers ive never had good tomato results so im hopeful!
Tanya via Facebook says
My tomatoes are NOT thriving. I think I might have used too much cattle manure…although it was beautiful and black and odorless!
I’m going to read this and maybe I can save my tomatoes! Thanks!
chuck patch says
i mix composted manure (well aged ,really black,no smell,)in a 50 gal drum ,i put about three heaping large pitch fork full of manure in the drum,i filll it with water,(and let set a couple days to get chlorine out i have city water).then i mix well. water in a circle in close to stem ,but not right into root area stay back a little in a circle around plant,i have had great success and have never hurt anything yet.
Bryan says
I have a terrible blight problem in my garden. there are woods in the common area in my neighborhood and i see spots on many of the leaves so it seems it will be an ongoing problem. I cut the leaves of where it is apparent but will not the the leaves from the trees falling in my garden. Will repeated sprays of the skim milk solution combat this or do you have any other ideas? Thanks. I eat tomatoes like apples and wouldnt last a year of resting the ground anyway.
Katie Kimball @ Kitchen Stewardship says
Bryan,
I wish I knew more to help you out, but I have no idea about the trees and whether they can impact the tomatoes or not, and how to help. 🙁 So sad for your tomatoes! 🙁 Katie
Bryan says
Well, I know the trees have blight and/or septuria. I can see it on the leaves that fall in my garden. Was just wondering if you had any ideas on the best way to combat an ongoing blight/septuria problem that will always be present. Thanks for the reply and yes it is very sad.
Sheila says
Blight got me late last year. I just rolled with it — I’d gotten lots of tomatoes already, so I picked all the green ones and made salsa verde. This year I haven’t seen any YET, probably because 1. I removed all old vines and rotting tomatoes at the end of the growing season, 2. I rotated the garden, so tomatoes aren’t growing in the same spot, and 3. I planted only the varieties that survived the best last year. I didn’t save seed, though, because I heard blight can be carried in seed — I used seed saved the previous year.
chris says
So I do that mixture spraying on the soil itself in the fall and early spring? what if I usually cover the garden over with a layer of leaves and add in new dirt the following year?
Katie Kimball @ Kitchen Stewardship says
Chris,
I haven’t personally done all this stuff, but yes, spray the mixture on the soil if you’re trying to get rid of blight, which can stay in your garden from year to year. 🙂 Katie
Rebecca M says
If you or any of your readers are interested, there will be a free webinar about Late Blight Control in Organic Gardens on July 21st.