chris thame writes
Whats going on? The marrows form with a nice little yellow flower at
the end and then they start to go yellow and rot.
I havent managed to keep one yet - theyve all gone
They are not laying on wet soil, in fact they are pointing upwards at
least 6 inches away from the soil
Any suggestions?

Not being fertilised?
Try and pollinating by taking a male flower (no little marrow behind it)
and sticking the business end into a female flower (the one with the
little marrow behind it).
--
Kay