Saying someone has a green thumb usually means they can make anything grow. But it can also mean they are successful in multiplying their plants. If you're like me, every time you walk into a garden center, you have a wave of jealousy mingled with pleasure. Plant collecting is my soft spot. But how do I get more plants, different species, even cultivars?

When I was a kid I used to wonder if you were to dig a hole all the way through the middle of the earth to the other side, when you got to the middle, would you be digging up or would you be digging down? Forget about the molten rock in the middle of the earth and the effects of gravity, too. Just ponder the hole.

Encore azaleas are causing a real stir among Georgia gardeners. Developed in Louisiana in the early 1980s, they're being promoted as "twice-blooming" (spring and fall) azaleas.