When is spaghetti squash ripe and ready to pick, and how should it be stored?
This article will help with when to harvest (go to the bottom half of the article): https://www.gardeningknowhow.com/edible/vegetables/squash/when-to-harvest-squash-best-time-to-pick-winter-or-summer-squash.htm
The squash can be stored in at room temperature in a somewhat cool and dark location, like in a basement or pantry, for about a month. Keep it dry.
How do you support butternut and spaghetti squash so it's not all laying on the ground?
Most varieties of winter squash are suitable to growing along a trellis or similar support system. If you provide a trellis, it will grow up the trellis. They will happily grow upwards. You just need to support the fruit. Tying the fruit to the trellis with panty hose works well. Also, when they set fruit, just tie the fruit in a cloth hammock (I like to use panty hose) to the trellis to provide extra support.
I am growing Spaghetti squash and the vines are thriving. I have many blooms and many small squash about 2-3". They seem to be shriveling and dying at this size. What can I do?
This indicates a pollination problem. You should try hand pollinating. This article will help you with that:
Yesterday vines were fine but this afternoon leaves are starting to wilt and lay over - main flowers are starting to droop over. In other plants I would suspect a water issue but other vegetables are doing fine and we haven't been particularly dry.
There are a couple of possibilities. One is borers https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pests-identifying-and-preventing-squash-vine-borer.htm
the other is bacterial squash wilt, though it's typically found early in the season: https://www.gardeningknowhow.com/edible/vegetables/squash/signs-and-treatments-of-squash-wilt.htm
We keep a compost heap that I put all veggie scraps in. Right now there is squash sprouting up. If I transplant it in my greenhouse, will it grow through the fall and winter here in east TX and maybe produce some? I will try anything once. I think it is either spaghetti of butternut squash. Thanks.
If you have it protected in a greenhouse, there is no reason it should not survive through the winter. It just needs to stay warm and well watered and it will grow just fine. I would recommend putting it in a larger tub. Once they get beyond the seedling stage, they do not like to have their roots disturbed, so you want to make sure it is in a big enough container that it won't outgrow it.
What can you do with squash that are still green on the vine? The season has turned cold and a lot of squash haven't turned yellow.
This article may help: https://www.gardeningknowhow.com/edible/vegetables/squash/ripening-green-unripe-squash.htm
My spaghetti squash is spreading like crazy. Can I cut back some of the new growth to contain it a bit? Also, some fruit are not thriving but think this is pollination problem.
You can cut back vines if you feel it necessary.
Leave at leave 3 fruit growing on a vine.
You can move vines around if the are in the way, gently lift them and move.
You will reduce your harvest by trimming back your vines.
Here are a few links.