Blossom-end rot of Tomato Plants

Blossom end rot on Tomato in Chicago garden.png

Blossom-end rot is a tomato disorder that I’ve been asked about a couple of times on Twitter and via Email. It isn’t a disease caused by garden pests or something transmitted through infected plants. Blossom-end rot generally occurs when a developing tomato fruit doesn’t get the necessary amount of calcium.

Fertilizing your tomatoes may not be of much help because even if your tomatoes are growing in nutrient rich soil, the problem is aided by uneven watering that don’t allow the tomato plants to make good use of the nutrients in the soil. Prolonged droughts or heavy watering followed by long dry periods can also lead to blossom-end rot.

The symptoms of blossom-end rot can start off as a small, tan-colored spot on the blossom-end of the fruit. It can first appear when the fruit is green or while it is ripening. The problem worsens and develops into a dry, leathery lesion.

If your fruit shows signs of blossom-end rot simply remove the affected fruits and make sure your plant is properly watered from here on out to prevent the rest of your fruits being affected. There is no need to discard the whole plant, just the affected fruits. 

When you water, provide a slow and steady drink at the soil level avoiding water getting on the stems,leaves and fruit– which will lead to other problems. This is especially important if you’re growing your tomato plants in containers. If your schedule makes it hard to keep a constant eye on the moisture
levels of your soil try making a slow drip irrigation system from
plastic soda bottles.  

Blossom-end rot isn’t just a tomato problem, it can also affect peppers and eggplants.


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  • Thanks for sharing this info--end rot, as you pointed out, is fairly easy to avoid. Another kind of "disfiguration" can happen to the top of tomatoes if it rains a LOT at once--brown marks, which i don't know the official name for. That happens when the tomato grows so quickly its skin gets stretched a lot and it turns brown--this is only skin deep and the tomatoes are still fine to eat, slicing off the top.

  • In reply to gardenfaerie:

    I know what you're talking about but I can't think of the name right now. I'm sure it will come to be right before I go to bed and by the time I wake up I won't remember.

  • In reply to gardenfaerie:

    I was afraid my purple Cherokee tomatoes all had blossom-end rot when they first started developing, but now it's just a thin brown circular line at the bottom of the fruits that looks more a brown 'stretch mark.' This is my first year trying purple Cherokee. Maybe it's just a characteristic of this variety. The tomatoes are very large, and grew very fast, but all still green, probably because they're not getting full sun. I hope they eventually ripen!

  • In reply to ssgardengirl:

    Keeping my fingers crossed for yours. Purple Cherokee are one of my faves!

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