I've just completed a new greenhouse, very close to our compost heap. Right in the corner of the greenhouse, a seedling has appeared, which must have come from the compost. I recognise the type of seed leaves, but won't know for a while whether it is a winter squash, courgette/marrow or melon. If it's a squash it may well be too rampant to keep, but otherwise I'll give the plant a chance and see what develops...

Evening Ken, when i did the same sort of thing i ended up with, short, fat stubby looking marrows. Not what i was really hoping for, i must say.

I think that family of plants tend to inter-breed very easily.

For now I can be patient; the time may come when I have to be ruthless.