Tomato plant rot?

Asked June 10, 2018, 8:24 PM EDT

Hi, I have two tomato plants that looked great until about 2 weeks ago. Now the leaves are dying and the tomatoes are rotting on the bottom. How do I fix this? They get a lot of sun and I water and fertilize regularly. There are also holes on the bottom for drainage. Thanks!

Ramsey County Minnesota

1 Response

It would appear that your tomatoes are experiencing blossom end rot. Judging from your question I would guess that you are growing your tomatoes in pots. Blossom end rot is especially common in tomatoes grown under these conditions.

This condition is due to an insufficient amount of calcium being taken up by tomatoes. Typically this is due to an inadequate amount of water in the soil. Tomatoes in pots need to be watered on almost a daily basis. You can improve water retention by putng a layer of wood mulch on top of the soil in the pot. Typically I also cover my tomato pots with black plastic. A slit is cut in this plastic so that it can fit around the plant. This plastic may need to be stapled down in places. When you water, just do so through this slit.

Blossom end rot can also be due to an excess of nitrogen in the soil. When you fertilize avoid using those fertilizers having a high level of nitrogen.

In your picture you showed some green tomatoes having this condition. If and when they ripen, most of the interiors of the tomatoes will be black. Also these black conditions can increase the chances of bacterial/fungal infection. You may wish to remove them at this time.

The following will give you further information about blossom end rot:

I generally have not seen blossom end rot affect the leaves. This leads me to believe that
something else is going on. Two possibilities are septoria leaf spot or verticillium wilt.
If you purchased your tomatoes from a greenhouse, most likely you bought a variety
that is verticillium wilt resistant. That means that the plants, beside blossom end rot, may also have septoria leaf spot. The following two sites describe these two conditions and their treatments:

Good luck!!