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Avoiding Tomato Blight & Blossom Rot – How To Keep Tomato Plants Healthy!

Looking for a way to keep your tomato plants healthy from tomato blight and blossom end rot? Then today’s article is a must read!

Nothing is more depressing than watching tomato plants wither away from tomato blight or blossom rot. Not only can it destroy your crop, but it can create additional garden issues as well.

tomato blight - keep tomato plants healthy
Nothing is more devastating that to watch healthy tomato plants wither away from blight.

Plants weakened from disease are an alarm bell for pests. And pests that become established on a weak crop will begin to attack and destroy other crops too. It is a downward spiral that can easily lead to a garden’s demise.

But as bad as both tomato blight and blossom end rot can be, there are a few simple ways to protect your crop from both. The key is understanding the root cause of each issue to prevent and/or eliminate both.

The Difference Between Tomato Blight & Blossom End Rot

Tomato Blight:

Blight is a fungal / soil borne disease that kills plants by destroying the foliage. It starts out with black spots appearing on leaves, and eventually takes over the entire plant. It can wipe out an entire harvest.

tomato blight
Tomato blight begins with damage to a few leaves, and eventually spreads to kill the entire plant.

Blight spreads through spores that find a permanent home in the ground. Spores that can overwinter and survive for years in the soil.

Blossom End Rot:

Blossom end rot is not a disease, but a condition that occurs when there is a lack of calcium in the soil. A small black spot appears on the ends of tomatoes, and rots the fruit before it can mature.

Blossom rot may not entirely wipe a plant out, but it can destroy the yields for sure. Now, lets take a look at how to keep both from happening!

How To Keep Tomato Plants Healthy From Blossom Rot & Blight

There is one major practice that helps eliminate both tomato blight and blossom end rot, and that is crop rotation.

The Importance of Crop Rotation

Tomatoes are one of the most susceptible vegetable plants when it comes to soil-borne disease. In addition, they are also heavy feeders of the nutrients that are in the soil. One of which is calcium, which when depleted, is the cause of blossom end rot.

Crop rotation in a vegetable garden

By planting over and over again in same location, the soil begins to lose valuable nutrients such as calcium. And at the same time, it is also more likely to become infected with the spores that cause blight.

But by rotating plants each year, you instantly minimize the potential for both issues. A new space in the soil means less chance blight spores are present. And more importantly, less chance the soil has been depleted of calcium from previous years crops.

crop rotation
Moving vegetable crops around to a new location in the garden is one of the best ways to fend of disease and pest issues.

For best results, never grow tomatoes in the same space for a minimum of 3 years. For potted tomatoes, the soil should be changed out every year. This gives your plants the best chance of success right from the start!

With that in mind, here is a look at additional ways to help keep your tomato plants healthy, and eliminate both blossom end rot and blight:

Preventing Blossom End Rot

Of the two issues, blossom end rot is a bit easier to manage. As mentioned above, it is not caused by disease, but a deficiency of calcium in the soil.

In addition to crop rotation, adding a bit of calcium and additional nutrients at planting time is usually enough to solve the issue.

keep tomato plants healthy
Blossom end rot is caused by a lack of calcium in the soil.

When planting, always mix in a shovel or two of compost in the planting hole of each plant. Compost is by nature loaded with a host of nutrients that help plants grow strong.

But to really boost the calcium, add in 3 to 4 crushed eggs shells in the planting hole as well. See : Planting Egg Shells With Tomatoes As the shells break down in the soil, they help to release calcium to the tomato plants roots.

Finally, mixing in a 1/4 to a 1/2 cup of worm castings in the hole will really build in the nutrients that tomatoes need to thrive! Product Link : Worm Castings

Preventing Blight

Eliminating blight is a bit more tricky, and really involves a few more steps to keep your tomato plants safe and healthy. Beyond rotation, which again is THE biggest key, there are a few additional methods that help to keep your plants safe.

mulching tomato plants
Keep tomato plants healthy by mulching and trimming up leaves to help eliminate spores from splashing up onto plants.

As plants grow, keep the bottom of each plant trimmed up to at least 6″ above the soil line.

This allows light and circulation into the plant, and makes it harder for spores to splash up to infect leaves. Good air circulation is also a big key in preventing mold on plants as well, and will go a long way to keeping your tomato plants healthy.

Always prune back any foliage that shows signs of blight or disease right away. Be sure to keep any of these infected or diseased branches out of the compost pile.


Every time it rains or the garden is watered, spores can splash up and find a home on leaves. But by mulching, you reduce or even eliminate that problem entirely. A few inches of straw, shredded leaves or grass clipping around plants goes a long way in solving the issue.

mid summer garden
Crop rotation and mulch both are big keys to keep plants healthy from blight and blossom rot.

As a final tip, be sure to clear out your tomato plants (and all vegetable plants) at the end of each growing season. Allowing old plants to over-winter is inviting disease and insect problems to take hold in the garden soil.

Pull up your plants, roots and all, as soon as they are done producing. We do not compost our tomato plants.

There is simply too much chance to pass on disease. We actually burn ours in the fire pit to kill off any spores, bacteria or insects, and then add the ashes to the pile.

Here is to keeping your tomato plants healthy this year! Happy Gardening – Jim and Mary.

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