Annuals are plants that must be replanted every year. That can be time-consuming and pricey, especially if you buy live plants instead of seed. Save money by planting perennials that will last three years or more, says Liskey.

"You don't have to replant them; they come back every year," Liskey says.

Another benefit to perennials is that many can be divided and the parts replanted in other areas of your yard, says Liskey.

"After a couple of years in the ground, they're big enough that you can dig those clumps up and divide them into three or four parts, and then replant those around" says Liskey. "Basically, you're getting free plants."

One more bonus: You can get together with friends and neighbors and trade your divided plants, adding variety and beauty to your yard for free, says Liskey.