That black spot is called “Blossom End Rot”. It develops on the “blossom end” of the tomato (or squash or pepper) opposite the stem.
Affected fruit can still be eaten, just cut off the black part. There is nothing harmful about the fruit, they just didn’t develop properly.
Good news, your plants are fine - they are not diseased and this is easily remedied. Blossom End Rot is usually more prevalent on the first fruit that appears and future fruit is sometimes okay even if the plant is not treated. It usually develops from rapid plant growth, extreme temperature differences, soil becoming dry or a lack of calcium when the first fruit is setting. This year we have found that some customers experiencing excessive rain fall have had a problem with Blossom End Rot.
A real easy way to treat this is to mix one cup of hydrated lime (powder) to a gallon of water and add it to the water well. You can find hydrated lime at most garden or hardware stores. You will only need to do this once – and any fruit that begins to develop after just a few days will be fine. Don’t overdo it though – adding too much lime will burn your plants.
Another easy way to treat this from the start is to order our specially formulated organic soil sweetener and blossom end rot block.
This should take care of it and you should still be enjoying your share of tomatoes this season.
You can use support stakes outside The Garden Patch™ as you would in a typical ground garden. You can put stakes into The Garden Patch™, right next to the tomato plants when they were about a foot tall and that will work just fine. Also, you can use tomato cages stuck right into The Garden Patch™ or you can put 1/4″ stakes directly into the 4 stake receptacles located in each corner of The Garden Patch.
You can also order our GrowBox Support Cage that is specially designed to work with your Garden Patch GrowBox.
Whichever method you choose, The Garden Patch™ will produce the best plants you’ve ever had with the best tasting ‘maters possible.