Blossom end rot on tomatoes
Tomatoes are one of my favourite crops to grow. They’re generally quite easy, but they have their problems. Frances sent me a photo of her tomatoes, which I identified as having Blossom End Rot.
Ever heard of it?
Although blossom end rot looks terrible (it really does), it’s actually fairly simple to treat.
Watch the video and read on for more details:
What is blossom end rot?
Alright, Frances asked if it was a fungal disease. A fair assumption, but it’s not a disease at all. Shocker!
It’s actually caused by calcium deficiency. But before you head off to the garden centre to buy a big old bag of calcium nitrate, let me tell you this.
Feeding with calcium isn’t going to help.
What causes blossom end rot?
This nutrient deficiency is rarely caused by a lack of calcium in the root zone. It’s normally caused by one or both of the following:
- Inconsistent watering: When the growing media dries out, the tomato plant has difficulty taking up and transporting calcium to the fruit. If the compost is saturated for long periods of time, this can also reduce calcium uptake.
- Susceptible varieties: Some varieties of tomato are just very prone to blossom end rot. I grew a variety once that was so prone to it that even with perfect watering, every single fruit started to rot!
What to do if your tomatoes get it?
The key to dealing with this nutrient deficiency is preventing it, and thankfully, that’s quite straightforward.
- Use good-quality compost: Well-produced compost holds on to a good amount of both water and air. It’s less prone to fluctuation than lower-quality products.
- Water regularly: If you have a free-draining but moisture-retentive compost, you should be able to water daily without problems for most of the summer. This will reduce the likelihood of the growing media drying out, thus reducing the incidence of this problem taking hold.
- Choose resistant varieties: Most well-produced modern tomatoes are fairly resistant. If you’ve had repeated issues growing a certain variety, stop growing it and try something new.
Have you had blossom end rot?
I’m interested to know if you’ve experienced this disorder. I also want to know what you think caused it. Was it one of the two causes I mentioned, or do you think there were other factors at play?
Happy growing.
Joe
Joe Vary Dip. Hort (Wisley), MCIHort, CMTGG
I'm a gardener, educator, consultant, and planting designer. Learn with me 1-to-1, or join my mentoring group and community.
This Post Has 2 Comments
Many thanks Joe for answering my question and even better posting this video and giving the full explanation, about the problem we were having with blossom end rot on our plum tomatoes. You will be pleased to know that we followed the advice you gave us and our crop of plum tomatoes are now in abundance and delicious! Thanks once again for your prompt reply and expert advice as always. We always enjoy your videos no matter what the topic is. Thanks again Frances.
I’m so pleased this helped you Frances.
And I’m also happy to hear that your plum tomatoes are on the road to recovery. Hopefully this means that you’re not growing an especially susceptible variety.
Best wishes,
Joe