Black bottomed Tomatoes with Blossom End Rot

25 July 2011

If you grow your own vegetable plants, you may be noticing a problem or two.....Tomatoes, especially those growing in pots, planters and growing bags are prone to a problem called 'blossom end rot'.  Its starting to show up now on greenhouse grown crops and shows as black, leathery and often flattened or sunken patches on the blossom end of the fruits.It is caused by a deficiency of calcium in the fruist, causing cells to collapse and die and discolour.  That's not to say the compost you're using isn't up to scratch, because blossom end rot results from an erratic supply of moisture and/or dry compost.  Plants take up nurtients from the soil in a soup-like or liquid form, and if there's not enough moisture, they soon start showing deficiency symptoms, with calcium being the first to show on tomato fruits.
So what can you do? The fruits are not infectious, this is just a deficiency, but cut off the affected fruits and then concentrate your effortss on keeping that compost good and moist (but not wet!) at all times.  Subsequent fruits should then be fine.
Next year consider using a larger planter for each tomato plant, and maybe even setting up a simple drip irrigation system, that way black bottomed tomatoes should be a thing of the past!
Occasionally blossom end rot also develops on peppers, so do the same with these too.

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