I figured it out! LOL so DON'T match anything near the leaves, the saplings or the small melons! Keep away from them till they've fully grown into a big watermelon - then you can match beside them. So - just like all the other fruits - line up the watermelons in rows of 3 or more then you get 30 points per melon!

mee too! HOW do I turn pieces into watermelons!?