I'm growing the personal size watermelons for the first time. Well, this is my first time growing any watermelons. I have 2 gorgeous green orbs of the proper size. One has a brilliant yellow spot on the bottom, a couple splits on the stem though it is barely starting to look dry. The closest tendril shows no browning whatsoever. The other one has a white spot on the bottom, stem has no splits or browning though the nearest tendril is drying. I can't tell by knocking on them. I don't want to ruin them by picking too early. Help!