The plants are huge and were healthy and producing very well. Now suddenly they have a white, powdery coating on the leaves and they are drying up and dying. What is it? Is there anything I can do? The same thing happened last year, but quite a bit later than this.
This sounds like powdery mildew. It can be devastating if nothing is done about it. This can be quite easily treated luckily, though. Neem oil is safe for your plants and works very well, but there are many ways to control it.
This article will help: https://www.gardeningknowhow.com/edible/vegetables/squash/powdery-mildew-in-squash.htm
What conditions should they be stored under if they do continue to ripen?
Yes, as long as they have already started to mature and show a change of color, then they will ripen off of the vine.
These articles will give you the information that you need: https://www.gardeningknowhow.com/edible/vegetables/squash/hubbard-squash-care.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/growing-spaghetti-squash.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/how-and-when-to-pick-acorn-squash.htm
I planted seeds of spaghetti squash in a pot and they are now showing yellow flowers that open in the day but close at night, but no squash is this normal ?
Here's an article about general growing conditions required by squash:
https://www.gardeningknowhow.com/edible/vegetables/squash/growing-spaghetti-squash.htm
Are you certain the plants have had enough time to develop fruit? If they've had the opportunity to pollinate, it may be just a waiting game.
Just in case, I'm going to give you a link to a series of articles that should help:
https://www.gardeningknowhow.com/search?q=spaghetti%20squash%20grow
Bought both plants at Home Depot. First year garden. Mushroom soil. Why are my leaves getting dark spots? Same on both plants. See Pictures
This appears to be a bacterial infection. Most commonly, this is from overwatering, or soil that does not have time to dry out between waterings.
You can try a bactericide, but plants such as these will often need to be restarted after the soil has had time to dry out and treatment is done.
These articles will help:
https://www.gardeningknowhow.com/garden-how-to/info/applying-bactericide-to-plants.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/growing-spaghetti-squash.htm
https://www.gardeningknowhow.com/edible/vegetables/zucchini/growing-zucchini.htm
I put seeds from spaghetti squash in dirt. They became plants. My question now is do I pick the curly suckers off before they bloom (supposedly to make the plant stronger) or do I leave them on.
Since you describe them as "curly," I'm thinking you're referring to tendrils. The short answer is no; unless you need to control the size of the plant, the tendrils are there to support the plant.
https://www.gardeningknowhow.com/edible/vegetables/squash/how-to-grow-summer-squash.htm
Plants are dead, but quite small squash. Is there any point in leaving them on the plant, or pick them now? Not even sure if they are mature.
Go ahead and pick them now and remove all traces of the plants from your garden. We have many articles on the possible problems with growing squash, but I'd wait until spring and start over again, following the tips in this article: https://www.gardeningknowhow.com/edible/vegetables/squash/growing-spaghetti-squash.htm
Hello, I am in need of some spaghetti squash guidance. My squash seem to be getting bigger and bigger and not turning yellow. I think I may a varietal called Tivoli. Which is a more white variety. Either way, I keep waiting for them to turn yellow and they just are getting bigger and bigger. I need some advice. Do you think you can help me? Any advice is much appreciated! Thank you! Josh
Here in Texas, spaghetti squash is ready to pick up late in the summer months (like you said, when they turn yellow)... about 40-50 days after you saw the flowers.