I planted several varieties of squash, beans, onions, cabbage, lettuce, etc. in the spring. I am very much a beginner. I can't tell whether what is coming up is a weed or not. I also don't know when something is ready to be harvested. Recommend a book or a website?
I assume you have rows of vegetables. You probably planted the seeds approximately the same distance apart? Repeated appearance of a plant that does not resemble the weeds that come up gives you confidence that they are the vegetable. In harvesting, you want your vegetable to look like those you see in a grocery store. Plants that produce their crop underground sometimes just have to have a sample pulled to check size. You will gain experience and start to recognize plants.
Why do I get blossoms on my squash plants but no squash? It has been very humid; if that is the problem, will they still set 'fruit'? Could it be lack of water? Should I be hand watering daily? The same thing happened last year. They are planted near tomato plants. . . could that be a problem?
This is typical behavior for a squash plant. They will produce mostly male (non-fruiting) blossoms early in the season and will gradually start to produce more female blossoms as the season progresses. Give it some time and you will see it start fruiting.
If you are seeing fruit but they are falling off, this article will help:
https://www.gardeningknowhow.com/edible/vegetables/zucchini/zucchini-fruit-fall-off-the-plant-before-they-are-full-grown.htm
My squash plants were looking healthy and growing really well. They are full of blossoms. This morning I noticed the leaves all have a white looking fungus on them. What might it be and what should I do?
it sounds like powdery mildew. These articles will help:
https://www.gardeningknowhow.com/problems/get-the-cure-for-powdery-mildew.htm
https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm
What is the black mold on my squash plants?
It is likely sooty mold and also indicates a pest problem. Here is more information:
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
My squash plants are falling over limp, so I've had to pull some of them up. On one such plant.the root snapped and I saw a white (grayish) grub-like critter with a black snout. So when I pulled other plants, I examined the roots and found they were all being eaten from the inside out. What are they, and what's the cause and remedy?
That is a description of a vine borer, though you normally find them in the stems rather than the roots. This article will help you with dealing with them in the future:
https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pests-identifying-and-preventing-squash-vine-borer.htm
My squash plants are big and healthy looking. I planted them back in late May and do not have any vegetables to show for it. I have big yellow flowers but no vegetables have resulted from them. What to do?
Thank you for sending us your question. This sounds like a problem with poor pollination. The following article(s) should be of some help to you: https://www.gardeningknowhow.com/edible/vegetables/squash/pollinate-squash-by-hand.htm
We have zucchini and yellow squash that are not bearing fruit. The blossom opens up, closes, and then drops off with absolutely no fruit. It has been exceptionally hot here in northeastern Ohio. Should the heat and not enough or too much watering be a factor? Should I follow the procedures for Blossom End Rot?
This is typical behavior for a squash plant. They will produce mostly male (non-fruiting) blossoms early in the season and will gradually start to produce more female blossoms as the season progresses. Give it some time and you will see it start fruiting.
If you are seeing fruit but they are falling off, this article will help:
https://www.gardeningknowhow.com/edible/vegetables/zucchini/zucchini-fruit-fall-off-the-plant-before-they-are-full-grown.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/pollinate-squash-by-hand.htm