My cucumbers keep dying/wilting

There are alot of things we take for granted, you just assume it's common knowledge and don't bother mentioning it.  So today i'm going to tell you that i'm not infallable, this is a little something that is probably not going to be too good for my reputation but hopefully might help you.  So far this season, probably in just the last 4 weeks, i have managed to kill five cucumber plants.   Not only have I killed them but I know why they've died, and I've actually done it twice.  OVERWATERED.  I bought 3 plants of femspot and planted them in the bed in the greenhouse which has an automatic watering system (an easy thing to set up, if you want to know more about that just ask me).  So they get watered regularly but because it hasn't been sunny the bed hasn't dried out, two died almost immediately and the third just about hung in there.  So I bought another two, still femspot, and planted them in the same place.  Again two died and the third has just started to wilt.  The water has been swithched off and i'm waiting for someone to turn the sunshine on!  The last plant has some aerial roots developing just above soil level so i've mounded the soil up to cover the roots and hope this will revive it. 

I always buy femspot plants.  Femspot because it's a reliable, heavy cropping variety.  And plants because the seed is so expensive and you only get a few in the pack.  It's also worthwhile noting that I stick with an all female variety.  This is because otherwise you have to manually pull off all of the male flowers as soon as they start to emerge.  If the male flowers fertilise the female then the resulting cucumbers will be very bitter.