Should I prune my watermelon plant?
I would not recommend pruning watermelon plants. Vining fruits and vegetables need the leaves to help convert the sun into energy, which then is used to help develop the fruit.
If your watermelon is getting too large for your location, try training it up a trellis. They grow well up trellises, just remember to support the fruit that grows while it is on the trellis. Making a hammock tied to the trellis for the fruit out of old pantyhose or other stretchy material will keep the fruit supported.
My watermelons never grow very large. How can I get them to grow larger?
These articles will help you:
https://www.gardeningknowhow.com/edible/fruits/watermelon/growing-watermelon.htm
http://www.clemson.edu/extension/hgic/plants/vegetables/crops/hgic1325.html
What mixture do I need to grow watermelons in sandy, east Texas soil?
Begin with a high nitrogen fertilizer, or compost, until flowers form and then switch over to a high phosphorus fertilizer to promote fruiting.
When planting seeds using a Jiffy 7 planter, how many seeds per hole?
Any time you seed you should put in two seeds just in case one does not germinate. If both seeds germinate, then you can pinch the weaker one off a little later.
What if you grow watermelons on concrete? Do they sometimes get squishy? Also, what soil or mixture is best for a garden? I heard from my mom that rotten chicken poop is the BEST, but only when they are about full size.
To keep them from becoming mushy or moist, you should place the watermelons on newspaper, cardboard, or a bed of straw.
As for chicken manure, this is best used when composted. This article will help: https://www.gardeningknowhow.com/composting/manures/chicken-manure-fertilizer.htm
How many watermelons grow on one plant?
There is no exact number for this as it varies depending on conditions and varieties, but typically, you can get at least 2-3 from a watermelon vine and often more than that if conditions are good.
What will happen if you plant the seeds too deep in the soil? I planted watermelon, squash, and cucumbers; and they may have been planted 1/2 inch to 3/4 inches deep. The package called for them to be planted 1/4 inch deep. It has been 19 days and they aren't up yet. The package said they should be up in 10 to 14 days.
Nothing really. They will just take a little longer to germinate.