Courgettes

Any ideas why odd fruit on mine are rotting at the end before they are ripe? Is it because they have touched the compost or should I have pulled off flower as it died?

We have 6 plants, 2 per planter approx 3ft apart and they look healthy - approx 18 fruits per plant so far (including those that are rotting)

lol. i'm going to put my OH off courgettes forever,.... i started with 3 scallop squash (UFO pattie pans), and 6 courgette plants. they were slow to grow, so mum got me some at the bootfayre, 9, as 1 was a cucumber... then i decided i liked the sound of crown prince squash, so bought seeds off ebay and grew just 2... then i liked the sound of summer crooknecks, so grew 2 of them and bought a butternut squash plant.... so i have a few squash plants on my lottie, just glad mum and me love em. i think the girls at work will be eating my courgettes for months to come.
(will try and freeze them too, but only got a tiny freezer)