I tried twice to get yellow squash and zucchini to grow from seed this year, and only a hand full came up (I planted A LOT) and THEN only two survived the birds and bunnies. So, I went and bought some zucchini plants to transplant, put them in the ground, and now they look like they're on death's door. They've got plenty of water. It's been raining every night here. Maybe they're not hardened off well enough? BAH. If these guys die, I quit.
BTW, last year, I had zero problems with my squash and I planted them elsewhere this year because I heard you should... Now it's nothing but trouble.