I planted Crimson Red watermelon seedlings (top) in a firepit that I converted to a garden bed. It's sharing space with a tomato (left), rosemary (bottom), and red pepper (right). Since there's 4 plants crammed into this garden bed, I decided to drape the watermelon vines over the concrete to make room. Is there any problem for the watermelon fruit to grow on a hard surface? I've been slowly building up this soil with a mixture of store bought soil and vegetable scraps, egg shells, fallen fruit, and nut shells for several years. I water this garden bed twice a week.
I noticed that the watermelon leaves are all curling inward. It looks wrinkly just like kale. Is this normal or a sign of some disease? The leaves are a decent green color. There's not much yellow. There's 3 watermelon fruit growing, They're all around 6 inches in diameter. The fruit started off squishy but now they're rock hard like the mature watermelons you find the super market. Is it normal for the fruit to start off soft?
I'm in California zone 9. It's been around 80 degrees Fahrenheit during the daytime for two months.