Can I move my tropical houseplants out into the garden now?
— Jerry, Evanston
Can I move my tropical houseplants out into the garden now?
— Jerry, Evanston
Tropical plants add interesting foliage color and texture as well as flowers to your annual garden displays. But since most of the plants we grow as houseplants come from warm regions, they cannot tolerate temperatures below about 50 degrees. They also need to be gradually accustomed to the shift from the low light and protection of the indoors to stronger light and variable conditions outside.
Monitor the weather forecast and let it guide you in determining the best time to start moving your plants outside. Once night temperatures are consistently above 50 degrees, gradually move houseplants outside to protected shady areas. You may need to move them back in again for protection later in May if cold weather is in the forecast.
The actual dates when these conditions occur will vary from year to year with the weather. If you are not sure whether the time is right, it is best to err on the safe side by delaying the move outside until June.
For most sun-loving houseplant species, it is best to start the plants off in light shade for 10 days or so to acclimate them to the strong outside sun. If plants are moved directly to full sun, the leaves may burn. White or brown patches on the leaves are a sign of sun scald.
If large houseplants are growing in lightweight plastic or fiberglass pots, place them inside a larger and heavier pot to prevent the plants from blowing over.
Pay close attention to watering when the plants are outside, as the growing medium can dry out more quickly than it did indoors.
In fall, you should be able to keep many tropical plants outside until night temperatures drop a bit below 40 degrees, because the plants will have been gradually adjusting to cooler night temperatures as the summer waned.
Tim Johnson is director of horticulture for the Chicago Botanic Garden in Glencoe (chicagobotanic.org). Send questions to: Gardening Q&A, Sunday, Chicago Tribune, 435 N. Michigan Ave., Chicago, IL 60611-4041; e-mail to sunday@tribune.com.
