|Oxalis Plant photo by Rebecca Anderson|
Many houseplants will get a boost from being outdoors during the warm summer months. Increased sunlight exposure will let them recover from the low light levels inside most homes. Since most houseplant originate from tropical areas, they should not be moved outdoors until night time temperatures are above 55 degrees. Place them in an area with partial shade and good wind protection. Ideal locations would include a covered porch or under a tree. After a few days, sun-loving plants such as jade (Crassula ovata), poinsettia (Euphorbia pulcherrima) and hibiscus (Hibiscus sp.) can be moved to a full-sun location. Christmas cactus (Schlumbergera sp.), umbrella trees (Schefflera arboticola) and citrus plants prefer to stay in the shade. Exposing a houseplant to excessive sun before it has been hardened off will cause photo oxidization, or a yellowing of the leaves. This process is the plant version of a sunburn.
Houseplants living outdoors will dry out more quickly than ones kept indoors. One way to combat this is to water more frequently, either by hand or by using an automatic drip system tied into an irrigation program. Another method is to dig a hole for a single pot or a trench for multiple plants and set the pots below ground level. Then pack peat moss around the pots. The soil will keep the pots cool and the peat moss will hold more moisture. With this approach, the pots should be rotated a quarter turn every two weeks to keep roots that might grow out of the bottom of the pot from becoming anchored.
Don't forget about your plants when fall comes around. When night temperatures start dipping into the 50's, trim off damaged or overgrown foliage. Fertilize one more time and check for any insect pests that need removed. Then bring your lush, rejuvenated plants in from their outdoor vacation for the long, cold winter. For more information about houseplant care visit the CSU Extension Houseplant and Indoor Gardening page for more detailed fact sheets.