My butternut squash is mature but I'm waiting for the stems to dry up. Meanwhile, we are having alot of rain and some of them are splitting. Should I just go ahead and harvest them now?
I'm new to gardening and this is my first year growing squash so take anything I say at face value.
From what I've read and what has worked for me so far is to actually pick squash when it's still young. Maybe 6 - 8 inches long. After that the skin gets hard and the taste bitter.
So I would say yes, harvest them now.
What you are doing is to harvest winter squash as a summer squash. Which is perfectly acceptable, and yes, you have to harvest it early to eat it that way. But most people want to harvest the winter squash as winter squash. So to do that, you let it mature on the vine until the skin is hard and the stem dries up. The hardened skin allows the squash to be stored for a long period of time before rotting. Hence the name Winter squash, because while it was grown in the summer, it could be stored for consumption in the Winter. (Summer squash is grown in the summer and consumed in the summer.)
The problem with early harvest is that it will be less sweet and not as tasty, and also not have the storage potential of squash that are left. The squash will continue to ripen as long as it's on the vine, afterwards it won't. But you can still cure it which will set some sugars. But a split squash won't feed anyone. So if it were me and I was confident I was going to lose them on the vine, then I'd probably harvest. But it's a personal judgement call as to what you want to risk. Maybe harvest some and risk some on the vine...
Best of Luck!