Blossom end rot!

I don’t think I’ve quite got the hang of courgettes just yet. Last year I grew a couple of them in the same large container, using shop-bought compost. I did harvest two decent sized fruit, but of the three or four other fruit that I noticed, all of them reached about 3 inches long and then started to shrivel away from the flower end. Rather like the ones in the picture, in fact – these are taken from one of the courgette plants I’m growing this year. However, I am managing a greater number of “viable” courgettes – four or five so far, off the one plant. Trouble is, I’m reluctant to just let them grow in case they too start rotting, so I pick them when they reach 4 inches long.

After doing some research on various Internet forums etc., there seem to be several reasons why blossom end rot can occur:

1. Inadequate pollination
2. Water getting into the flower and rotting the fruit
3. Too cold
4. Lack of calcium.

Not sure if inadequate pollination is the right answer – surely my courgettes wouldn’t even reach a length of 2-3 inches if that were the case? I can definitely see the logic behind (2), but I’ve tried removing some flowers as an experiment and the courgettes in question STILL succumb. I’m wondering if flower removal is enough – perhaps the problem is caused by a damp atmosphere inside the container, which could certainly be the case because the plant is in a very deep bucket, which I’ve only filled half way. Perhaps the flowering stalks of a courgette plant need to have access to regular wafts of fresh air.

“Too cold” – well, that isn’t a problem any more. We’re right in the middle of a heatwave at the moment. And as for the lack of calcium: that could be an idea. I planted this particular courgette in pure compost with no garden soil at all, so maybe it just needs a bit of lime. Looks like a trip down to the beach to pick up a few bits of chalk then!