[MichelleC]

I'm currently growing in an unheated greenhouse one Sweetheart and one Orange Sherbet. I've let them grow to the roof but have read that I should have pinched them out when 5 to 6 leaves tall. They have lots of male flowers and no females yet. I will hand pollinate them but is it too late when I eventually catch the females open?

[Trillium]

I wouldn't trim anything back until those female flowers appear. Only when you're sure that they're actually growing as fruit should you then trim back the leaves.

And yes, it's getting a bit late in the season for melons but you might get away with it in your greenhouse.