My tomatoes are looking burnt and brown/yellow around the edges of the leaves, what is the problem? Leaf problems such as burning and darkening can be due to a variety of causes, but are often the result of irregular plant maintenance.
Tomato plants need close attention and maintenance in order to grow at their best. Stress from drought can first show up as browning, drying leaf edges before spreading farther into the plant’s tissue. Fertilizer burn damage can cause similar symptoms due to contact damage to tender roots in the soil. Both of these conditions can be helped by upping the frequency of watering, as well as providing deeper, longer water sessions. A Deep, complete soaking encourages tomato roots to reach deeper into the soil, away from shallow, condensed fertilizer applications.
Hold back on any fertilizer for a few weeks and watering deeply over the time period will help flush out the concentration of excessive fertilized and will allow the tomato plant to recover. Once the plant’s leaves start looking normal again you can gently reintroduce a lighter dose of fertilized back into your watering routine.