You’ve planted the tomato seeds, watched them grow, and now you’re finally starting to get some beautiful tomatoes! But what’s this? Who put this disgusting black scab on the bottom of my beautiful tomato?
That horrible scab that’s ruining your tomato is called Blossom End Rot.
Blossom end rot is caused by two things: a lack of calcium and inconsistent watering. While the best cure for blossom end rot is prevention, it can be reversed once it’s started. In this blog post, I’ll let you know how to fix blossom end rot with three easy steps! Let’s get into it.
P.S. There are a couple more reasons why your plants may have blossom end rot. I’ve chosen to focus on this reason and solution because not watering enough is the culprit 80% of the time. If my process doesn’t work, you’re unfortunately in the other 20% and will need to do some further research into why this is happening in your garden.
3 Steps for Fixing Blossom End Rot
1. Remove all Affected Tomatoes
Unfortunately, once a tomato has blossom end rot, it won’t go away. However, you can still save the plant and any remaining tomatoes it produces. Put all rotten tomatoes in your compost and cut your losses.
2. Water with Powdered Milk
Those tomatoes need some calcium at the root–stat. While egg shells are great, their calcium won’t be picked up by the plant until they start decomposing. That’s great for a few months from now, but it doesn’t help your immediate problem. Instead, mix powdered milk into your watering can for a quick hit of calcium that doesn’t resort to using lime. Lime should only be used if you know you have a soil PH problem.
EDIT: When I first wrote this post, to the best of my knowledge, this powdered milk solution was effective. I have since learned that powdered milk does nothing and that the calcium in powdered milk isn’t actually absorbed by the plants. I debated for a long time whether to change the post entirely but found the title would not be as clickable with the removal of this detail. Does that make me a bad person? Maybe. Sorry for the clickbait, as it was not my original intent. Just know the powdered milk does nothing. You just need to water more.
3. Water Every Day (Twice a Day in Extreme Heat)
Tomatoes need consistent water. In fact, skimping on watering earlier in the month is likely what caused blossom end rot in the first place. In the past, when my tomatoes succumbed to blossom end rot (due to inconsistent watering because we were renovating our bathroom and not living in our home) it took two weeks of daily watering (unless it rained) to reverse the problem. Thankfully, I still ended up with many of the lovely tomatoes you see in the pictures in this post.
Optional: Use Mulch to Further Prevent Blossom End Rot
Finally, if you want to hold in the moisture in your soil, surround your tomatoes with 2-4 inches of shredded newspaper or wood chips. This easy organic mulch will retain moisture, prevent weeds, and add more nutrients to the soil over time.
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SOMETIMES TOMATOES ARE JERKS
Over the years I’ve come to realize that, with certain varieties of tomatoes, it seems like the first tomato to ripen always has blossom end rot, no matter how much you water the plant. And, for some reason, all the tomatoes that grow afterward do not have blossom end rot.
This is very annoying.
However, if you find that your tomato plant consistently pumps out tomatoes that get blossom end rot week after week then you do in fact have some sort of problem. This is likely a calcium deficiency, especially if you’ve been watering consistently and it’s still happening.
A NOTE ON CALCIUM DEFICIENCY IN TOMATO PLANTS
What’s confusing about the blossom end rot problem is that even though it’s caused by a calcium deficiency, in something like 90% of the cases adding some sort of calcium isn’t really what the plant needs. It usually just needs more water to access whatever calcium is already in the soil.
Think of this in a similar way to taking Vitamin C with Iron. Vitamin C helps the body absorb iron, just as the water helps the tomato plant absorb the calcium in the soil. If you’re already taking Iron, it’s not that you have to take more of it, but rather, you might need to take some Vitamin C to increase the probability of proper absorption.
In other words, you are creating a better environment for the absorption of deficient nutrients.
In the same way, it’s not that you have to give tomato plants more calcium, it’s that you have to increase their chances of properly absorbing the nutrients from the environment they’re already in.
There you have it! Blossom end rot isn’t fun, but you don’t have to let it ruin all your hard work in the vegetable garden. Find me on YouTube, Facebook, Instagram, and TikTok for more cold-climate, short-season gardening tips and to follow my gardening journey in real-time!
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