Early Blight is a fungal disease that attacks tomato plants starting on the bottom leaves of the plant and works it’s way upwards. The leaves start turning yellow and get blotchy. If left unchecked, it can take over your plant killing it although it won’t die immediately. Where does it come from? It comes from water splashing soil up onto the lower leaves. The culprit is a bad soil fungus (there are good soil fungus as well). That’s why you always see it start on the bottom leaves. Early Blight should not be confused with Late Blight which is prevalent in the northeast. We don’t have Late Blight out here in the southwest (at least not yet).
There are several things you can immediately do to help with this disease if you get this.
1. The first thing you do is trim off the affected branches where the leaves are yellow. Yesterday I trimmed all the lower branches off my tomato plants whose leaves were yellowing. Considering we haven’t had much rain I was surprised quite a few plants had a little showing. I’d much rather deal with Early Blight than Curly top virus (which is always fatal and not much we can do about it). At least you can control Early Blight. Keep trimming up your plant as needed.
2. Trim any branches to make sure they don’t touch the ground
3. Stake or tie up any branches that might touch the ground.
4. Mulch with straw underneath the plant so the soil can’t splash up on plant when it rains or if you water overhead.
4. Use ‘Serenade’, an organic fungicide which provides protection from a broad spectrum of common fungal and bacterial diseases. Early Blight is one of the fungal diseases it can control. Spray it on when the leaves are dry. It is rainproof , non-toxic for bees and other beneficial insects. Respray every 7 days. Spray all parts of the plant-both on top and underneath till dripping.
Serenade is also good to spray on other vegetables. Spray for powdery mildew on squash, cucumbers and melons and leaf rust on beans. I use it for all my vegetables. Don’t wait till you get the disease—it works best as a preventative but you can control many fungal diseases with Serenade.