ive got tomato plants in my garden and the tomato,s that are growing on them have got like a brown circle on the bottom please could someone tell me what cause,s it and how can it be treated
I believe it`s called `Blossom end rot`!!! Missieb has explained why. Not much you can do for the ones already affected, but follow their advice from now on.
Additionally, for blooms that have not set fruit, you can spray with with an inexpensive calcium based spray available at your garden store to help keep the new tomatos from developing blossom end rot. Also, use some mulch around the base of the plants to help maintain damp earth, as suggested by the others... old newspapers held down by a little dirt and wetted are good for this...