Tropical plants are, by definition, native to the tropical regions of the world. Many are grown in cooler climates for their unusual foliage or flowering habits. In tropical climates, such as those found in USDA hardiness zone 11, tropical plants can be grown outdoors year-round. In cooler climates they must be grown as annuals or container plants that can be moved into sheltered locations during cooler seasons to protect them from frost. Tropical plants usually need additional care to thrive in the dry, low-light conditions found indoors.
Consult a farmer's almanac or your local county extension service to discover your first and last annual frost date for your area. Most tropical plants are killed or damaged by frost. Knowing these dates will help you determine when to plant tropical plants, such as impatiens for annual color, as well as when to move potted houseplants outdoors and back indoors for winter.
Start tropical flowers such as impatiens from seed up to eight weeks before the last annual frost date of the year. Fill an egg carton with peat moss and hollow out a planting pocket in each egg cup with a pencil point. Place the seed of each flower twice as deep in the soil as the flower's width and cover with soil. Fine-grained, pollen-like seeds (such as the kind made by petunias) can be pressed into the surface of the soil and left uncovered. Water the tray with a misting bottle and place plastic wrap over the tray. Put the tray beneath a grow light. Remove the plastic when the seedlings sprout. Continue to grow the seedlings in the tray until you can move them outdoors. Then transplant them into larger containers or into your landscape. Tropical flowers are typically planted in landscapes in cooler climates as short-lived annuals. They can provide instant color in hanging baskets, or as ground cover.
Harden off tropical plants before leaving them outdoors by moving them into the shade during daylight hours for three to four days. Move tropical plants to a location where they will receive the optimal amount of sunlight.
Position potted tropical plants beneath a misting system to help raise the humidity around the plants. Most tropical plants perform better in a humid environment.
Check tropical potted plants daily and water so that the soil remains as damp as a wrung-out sponge. Add a liquid fertilizer formulated for tropical plants to the water.
Plant tender bulbs, such as elephant ear or canna, in spring. Dig these plants up in fall and allow them to completely dry before removing foliage. Store them in a milk crate or paper bag filled with peat moss and place them in a dark, dry room with good air circulation.
Prepare tropical plants to move back indoors by placing them in a shady location for several days. Groom plants to remove insects and then bring them back indoors before you begin to use your household heating. Tropical plants will adapt to the change in climate and lighting conditions better this way.