Hello Garden Gals and Guys! Welcome back to Fat Earth. Today’s post is about a common disease that affects the leaves of tomato plants. It’s called early blight. I found it on quite a few of my tomato plants.
First of all, don’t panic. Here are some pictures to familiarize you with what it looks like so you can spot it in your own garden.
You can see the yellowing of this leaf and little brown spots as well.
Here is another leaf where the disease has progressed a little further along.
So what causes this? Well, we’ve had a LOT of heavy downpours over the last few days. Early blight is a fungus that overwinters in your soil. All it takes is a good heavy rain for those spores to splash up onto the bottom leaves of your plant and–voila!–you’ve got early blight.
Having a ground mulch does help, but not entirely. My garden is mulched but the spores still found their way onto my plants.
Here’s how to spot it. It usually starts out as small brown spots on older leaves that grow larger very quickly. Then a yellow ring surrounds the brown spots, also called lesions. It can spread to the stem of the plant, and eventually the fruit as well, and cause brown spots on the fruits too.
The spores are also carried by the wind, so it can spread throughout your garden quickly and even to other gardens in your neighborhood. It can also come into your garden if you have purchased infected plants
Here’s what to do if you have it.
- Cut off the infected lower leaves to help keep the disease from spreading upward.
- Throw away the infected branches immediately. Do not leave them lying in the garden and do not compost them. Some experts say you can “hot compost” (meaning your compost pile needs to exceed 120 degrees Farenheit in order to kill the spores) but I don’t take any chances. I don’t compost them. I throw them away in the trash immediately.
- Keep your plants mulched to reduce soil splashing onto the lower plants (in my case the mulch didn’t prevent it but it does help).
- If removing branches doesn’t work, apply fixed copper (an organic fungicide) according to the directions on the bottle. You can get this at your local garden center
- Continue to monitor your plants carefully
It will take vigilance to keep this under control, but if you follow these tips, you will hopefully still be able to have a good harvest.
You can see a video I made about it here.
Until next time…