Annuals, plants that grow, flower, set seed and die throughout the growing season, are a natural choice for containers. Once the season is over, simply dump the contents of the container into the compost pile, then wash and store the container until spring comes around again. Easy-to-grow container annuals that tolerate full sun include lantana, petunia, verbena, ivy-leaved geranium, sunflower, zinnia and marigold.
A wide variety of hardy and tropical flower bulbs do well in containers. Growing bulbs in containers makes it easy to move the tropical ones into a frost-free winter location. They also give gardeners in cold climates a way to grow hardy spring bulbs without the hassle of planting them in the ground in the fall. This is advantageous because deciding the best place to plant them once spring arrives is easier. These hardy bulbs are easy to transplant into the garden either before or after they bloom. Tropical bulbs that tolerate full sun include canna, pineapple lily and dahlia. Hardy bulbs that thrive in containers in full sun include daffodils, tulips, daylilies, iris and crocus.
Container-grown perennials are not as hardy as those grown in the ground. This means that, if you are in a U.S. Department of Agricultural hardiness zone 4, you should choose perennials hardy to USDA hardiness zone 2, if you intend to leave the perennials in the container year-round and not move the containers into a frost-free location during winter. Good drainage is essential, so the roots are not waterlogged during the winter months. Perennials that thrive in containers in full sun include coneflower, sea holly, yucca, creeping jenny, butterfly weed and globe thistle.
Shrubs, like perennials, thrive better in containers if you choose ones that are hardy in at least two hardiness zones colder than the one you reside. Another thing gardeners in cold climates can do to ensure the survival of container-grown shrubs that are too large to move, is to mulch the pot, including the top of the pot, with straw or another insulating material. An advantage of container-grown shrubs is they are often smaller than the ones grown in the ground. Emerald arborvitae, blue star juniper, blue mist spirea and Japanese holly all thrive in containers in full sun.