Originally Posted by Steve Upton

Hi,

I have been growing some tomato plants in grow bags outside, 3 Alicante and 3 Sweet Millions. They are good strong plants with lots of blooms and nice thick stems. Each plant is about 4.5-5 feet tall.

I have created a water mechanism that consists of 2 x 2ltr drink bottles with the bottoms cut off and a tube stuck into the top of the bottle. I have put the tubes down into the grow bags so this will water the tomato plants directly to the roots. I just fill up the bottles each night and I know I have given the grow bags 4 ltrs of water each night.


Everything looked great up until a few nights ago, I noticed that some of the Alicante newly formed tomatoes have started to produce black bottoms where the bloom was. I am assuming this is Blossom End Rot. The other Alicante plants in the same grow bag looks unaffected and the 3 sweet millions in the other grow back look very healthy.
The questions a

I am over watering the tomato plants? I was under the impression that tomatoes love water when producing fruit.

The soil is certainly moist all the time, as the weather has not been very hot recently. But I have put holes in the bottom of the bags for drainage. I am not getting a huge amount of water loss from the bag when watering.

I also understand that Blossom End Rot is a cause of calcium deficiency. Can I add calcium to the grow bags to prevent the other tomatoes suffering this problem? If so how?

Steve