Black spot on the bottom of tomatoes

[tomatorichard]

I am growing tomatoes from a Topsy-Turby planter (my first time at this).

I noticed this morning that 3 of the young tomatoes have black spots on the bottom of them. What is it and what does it mean?

Thank you for your help!

[Kisal]

Welcome to the forums!

I'd like to help, but "black spots" could be anything! Is there any way you could post a picture? There are some instructions here about how to post pics:

https://www.helpfulgardener.com/forum/viewtopic.php?t=8910

[thedawid]

Sorry, I don't have a pic to post (yet) but I would love to get help on this issue. I have a topsy turvy and I left for the weekend (so it didn't get watered for two days) and the first fruits that appeared had rotted on the bottom with a black color. I opened them up and found the rot went to the core, so I picked those off. Should I worry about this problem with other fruits on there? How can I avoid this problem? Thanks for your help.

[Kisal]

I'll hazard a guess, and say it's blossom end rot, which is caused by a calcium deficiency in the soil. It's quite easy to remedy. See the Sticky at the top of this section, or use the search box on the upper left of most pages to find previous threads on the subject. It's been discussed here quite a lot.