Here's a trick to switch out garden plantings without ever lifting a trowel. Place plastic pots directly into landscaping beds. Then, drop seasonal plants—pot and all—right into the hole. When the blooms fade or the season changes, remove the old pot and switch in a new plant. Be sure to choose pots with adequate drainage holes. To make your temporary plantings look at home next to perennials, cover beds with a layer of mulch.