Tomato leaves turning black on edges - Ask Extension
Hello – my tomato plant started turning yellow on the lower leaf edges, curling a bit, turning black or gray, and drying out. I thought this was a n...
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Tomato leaves turning black on edges #875969
Asked July 05, 2024, 8:50 AM EDT
Hello – my tomato plant started turning yellow on the lower leaf edges, curling a bit, turning black or gray, and drying out. I thought this was a normal lower leaves for seed grown tomatoes, which I thought this was. I only have one. Today I see that this problem continued to go up the stems into other new leaves, black around the edges at first. I can’t really figure out which of the tomato diseases it could be. It now it has a few flowers and a few tomatoes already.
I bought this plant almost 3 weeks ago and planted it almost immediately in Kellog gardens raised bed and potting mix, some compost from our Canton Township compost program and a little Soil Moist. It gets plenty of sun and I water it every day or every other morning. It gets very hot on my deck, sunny from morning through two or 3 o’clock and I have a mister that runs 10 minutes every hour during the day to cool the deck a little, but it is not spraying near the tomato plants.
Wayne County Michigan
Expert Response
Your tomatoes are affected by early blight. Early blight is a fungal disease caused by the fungus Alternaria linariae. This is a common foliar disease of tomato plants that can result in defoliation and reduced yields. The fungus overwinters in soil and on plant debris. It can also be transmitted on seeds and transplants. Early blight is typically splashed by rainfall onto lower leaves early in the season.
To help control early blight the following points may help
- Provide adequate spacing to increase air circulation and remove all suckers that emerge from the plant base
- Keep plants well mulched to minimize soil splashing
- Use drip irrigation instead of overhead watering if possible. If not possible, water at the base of the plant
- Do not work around the plants when they are wet
- At the first sign of Early Blight remove infected leaves and the lower leaves within twelve inches of the ground. Do not compost the removed leaves. Then at the end of the growing season remove and destroy infected plants
- Rotate your vegetables so that you are not planting members of the squash family in the same location
- Several fungicides are registered for use against Early Blight. Preventative sprays are effective but are only necessary in areas with a history of Early Blight. Make sure that you read and follow the manufacturers’ directions carefully.
The following article contains more information on early blight: Early blight in tomato and potato | UMN Extension
Thank you for your question and have a great gardening experience.
