Every year I start to lose my squash and zucchini after only 2-3 pickings of the fruits. They start to rot before they are large enough to harvest and then the plants die. What is causing this?
The following article should be of some help to you: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-blossom-end-rot-causes-and-treatment.htm
Squash blooms but stays below normal size. Plants are healthy.
Generally, this is due to poor pollination. Squash will produce fruits even if no pollination has occurred, but they will only grow 1-2 inches and then die. This can easily be corrected by growing bright-colored flowers (like marigolds or zinnias) close by to entice bees to the area. You could also hand pollinate them. Here's an article that may be helpful: https://www.gardeningknowhow.com/edible/vegetables/squash/pollinate-squash-by-hand.htm
Too much fruit set can also lead to small fruit size as well. In addition, a lack of water can decrease the size of your squash.
What if you have large, healthy squash plants but no fruit? What would cause this?
There could be several things happening.
If you are not getting flowers, there may be too much nitrogen in the soil. You can try adding a phosphorous rich fertilizer to the soil to help correct this.
If you are getting flowers and they fall off, check if they are male or female flowers (https://www.gardeningknowhow.com/edible/vegetables/squash/female-male-squash-blossoms.htm). If you are only getting male flowers, this is normal and you should be getting female flowers (and then fruit) shortly.
If you are getting female flowers and they are falling off, it is a pollination problem. These articles will help:
https://www.gardeningknowhow.com/garden-how-to/beneficial/insect-pollination-process.htm
https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/pollinate-squash-by-hand.htm
What is the best solution to rid the squash growing area of the borer? If I use nylon to wrap root area, how can I do that without harming the plant?
This article will help: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pests-identifying-and-preventing-squash-vine-borer.htm
What causes the leaves to start turning brown and wilting, even when they have water? They are in plastic mulch and have drip irrigation. Some have not even produced fruit and they are drying up and dying. Also, all my tomatoes' leaves have started turning upward, leaves turning brown and dying. What causes this? They are also in plastic mulch and have drip irrigation.
For the squash, it sounds like vine borer. This article has more information:
https://www.gardeningknowhow.com/edible/vegetables/squash/squash-pests-identifying-and-preventing-squash-vine-borer.htm
For the tomatoes, it could be a wilt fungus. This article has more information on that:
https://www.gardeningknowhow.com/edible/vegetables/tomato/wilting-tomato-plants.htm
Or it could be leaf curl. Here is more information on this:
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-leaves-curling.htm
Why are my squash flowers dropping?
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. Here is more information: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-blossoms-falling-off-vine.htm
Here is how to tell a male from a female blossom: https://www.gardeningknowhow.com/edible/vegetables/squash/female-male-squash-blossoms.htm
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
This is the first year I have tried growing anything at my home. I planted one squash plant and it has done so good. It is huge. Well, it started producing and the little squash have started turning brown and shrivelling up. What could cause this, and is it going to affect my cucumber plants that are just starting to flower?
This article should help with that: https://www.gardeningknowhow.com/edible/vegetables/squash/squash-fruit-falling-off-the-plant.htm