I've talked a lot about bringing outdoor plants inside. The opposite is even more fun, because when you let your houseplants loose in the garden, they really get to show their true colors. I do this with asparagus ferns, spider plants and wandering Jews. Tropical plants are especially good candidates. Persian Shield, which has the unfortunate botanical name of Strobilanthes dyerianus (sounds like a disease), is a tropical plant with iridescent purple-pink or silvery-white leaves. Although it is only hardy in USDA Zones 9 and above, it is ridiculously easy to grow as an annual or houseplant. You could snip a few cuttings this winter and have a wonderful clump of glowing plants ready fro spring.
One of the things I love about Persian Shield is how well it handles high humidity. A plant that doesn't wilt or turn powdery white in hot, hazy summers earns a spot in my garden.Any other suggestions?