Tomato blight primarily affects the leaves, stems, and fruit, showing up as dark, spreading spots or lesions. The appearance and behavior of blight vary slightly depending on the type, with Early Blight and Late Blight being the most common:
Treat tomato blight by immediately removing affected leaves and disposing of them in the trash—never compost them. Disinfect your pruners between each cut. Prevent further spread by applying a copper-based or chlorothalonil fungicide, or a homemade baking soda spray.
You may see the following symptoms on tomato plants with blight: The initial symptom of blight is a rapidly spreading, watery rot of leaves, which soon collapse, shrivel and turn brown.
Yes, unblemished tomatoes from plants with blight are safe to eat. However, the fungus itself can cause tissue damage and alter the fruit's acidity. Follow these best practices to ensure safety:
You can save the plant if it has early blight (a common fungal disease), but late blight is fatal and requires immediate destruction of the plant. To save blighted tomatoes:
Yes, a diluted hydrogen peroxide spray can help treat and control tomato blight, specifically early blight and various leaf spots, by killing fungal spores through oxidation. It works best as a preventative or early-outbreak treatment to prevent spreading, often mixed at a ratio of 8–12 tablespoons of 3% hydrogen peroxide per gallon of water.
This spray of water and baking soda will change the leaf's pH from around 7.0 to around 8.0. This change is enough to kill and prevent all blight spores!
Can I reuse soil after tomato blight? Yes, absolutely. Just as blight cannot live in compost, it also cannot live in soil. It's fine to plant tomatoes in the same spot the following year.
Regardless of what you might read or see in nursery promotions, planting tomatoes in October or November is not a fruitful experience, literally. The night temperatures are too low for the flowers to set fruit. Tomatoes planted in August or early September will grow quickly in the warm soil, warm nights and long days.
Early blight (caused by the fungus Alternaria solani) primarily affects tomatoes, potatoes, and other nightshades. It is easily recognized by circular brown spots with dark, target-like concentric rings that often develop a yellow halo.
Whether tomato blight stays in the soil depends entirely on the specific type of blight affecting the plants.
The best treatments for tomato late blight rely on preventative contact fungicides like chlorothalonil (e.g., Daconil) for conventional growers, or copper-based sprays for organic gardening. Because late blight is caused by a highly aggressive, wind-borne water mold, these fungicides must be applied preventatively before the disease takes hold.
Baking soda (sodium bicarbonate) is used to control fungal diseases, deter pests, and slightly reduce soil acidity. However, it must be applied with caution; overuse can cause dangerous salt buildup and damage plant tissue.
To prevent blight, start applying fungicides 2 to 4 weeks after planting (or when the plant reaches 1–2 feet in height). If you see early symptoms (yellowing lower leaves with dark spots), begin spraying immediately.
Neem oil spray for tomato blight treatment
If your tomato plants are suffering from blight, spray them daily for 7 days with Neem oil and water spray. Make sure to get on the bottom of the leaves too. It is non-chemical and natural so is not harmful to the bees.
Yes, blight spreads aggressively and will easily jump to other plants. It travels via airborne spores, splashing water, wind, and contaminated tools.
Coffee grounds provide tomato plants with slow-release nitrogen for leafy growth, trace minerals like potassium and magnesium, and beneficial organic matter. They also help improve soil drainage and can slightly deter pests like slugs and snails.
As the growing season draws to a close, tomato plants are often still loaded with fruit. To speed ripening late in the season, remove the growing tip of each main stem about four weeks before the first expected fall frost.
Never plant fennel, brassicas (like cabbage, broccoli, and kale), potatoes, or corn near tomatoes. These plants can stunt tomato growth, compete aggressively for nutrients, or spread devastating diseases and pests.
To kill blight (such as fungal spores and bacteria) in soil naturally, use methods that focus on soil sterilization, beneficial microbe competition, and physical barriers.
Encouraging the last few to ripen
The simplest is to bring them into a warm room and place them in a paper bag with a ripe banana or apple. Both release ethylene gas, which encourages ripening. Keep the bag loosely closed, check daily, and you'll often find the tomatoes take on full colour within a week.
Early blight and septoria leaf spot spores survive the winter in the ground, causing the disease to return next year. Late blight does not overwinter in the soil because it requires live tissue to survive, but wind can carry spores up to 30 miles away from infected plants.
Treat with hydrogen peroxide or copper fungicide as soon as blight starts to appear. Good luck! You need a copper based spray and remove any leaves that may contact the ground. Dont plant in soil that had a crop with blight in it previously.
Dawn dish soap is generally not safe to use on plants as a regular pesticide or cleaner. While some gardeners use highly diluted mixtures for pest control, Dawn is a detergent rather than a true soap. It is heavily formulated to strip oils and can easily burn foliage or damage the plant's delicate immune system.
Application Timing: Begin applying Bayer Garden Potato Blight Control at the first signs of blight or when the weather conditions become favourable for blight development (e.g., wet, humid conditions). Continue to apply it throughout the growing season at regular intervals as recommended on the product label.