I would bet that it is a pollination problem in spite of evidence to
the contrary.
Go out in the morning on a day when rain hasn't washed away the
pollen. Pluck a male flower, remove the petals, and use the
resulting "paint brush" to pollinate a couple of fresh female
flowers. If those flowers produce a squash, you'll know the bees
haven't been doing their job.
If I'm right about the pollination, the problem will probably solve
itself after the weather gets a little warmer and dryer.
Good luck.

Steve


Orin Hargraves wrote:
I've planted a winter squash this year called Lakota. The vines are
very productive and healthy looking, but every fruit turns yellow and
withers shortly after the blossom withers. Help! Is this a nutrient
problem? Everything else in the garden is healthy. There are plenty of
insects visiting the blossoms (and plenty of simultaneous male
blossoms) so I don't think it's a pollination problem. At this point I
wonder if I'll have any mature squashes.

Our summer so far (N MD) has been fairly wet, with about average
warmth. Any tips appreciated!

Orin Hargraves