The question always arises as to what to do with them during winter. If you take them inside and leave them there, it doesn't take them long to start looking terrible. They love high humidity and hate the warm, dry air inside a home in winter. By spring, you are left with defoliated ferns.
Sometimes your best course is to just throw them away and buy more next year.
But if you're willing to take a few steps, you can keep your ferns alive through winter.
If a fern is hanging on a porch, you need to move it where it is under the overhang so it won't become frostbitten. Sheltered this way, you can leave a fern out when it's 28 to 32 degrees.
The direction your porch faces influences how low the temperature can get. If you are facing northwest (the direction of the cold winter winds), place ferns up against the house if the temperature drops below the 26-28 degree range. Lower than this and they should be put inside.
If your porch has a southwest exposure, ferns could probably stay outside if the temperature drops to around 22-24 degrees, if you set them against the house. There would be only a few times each winter when you would need to bring the ferns in from a southwest-facing porch.
When you do need to bring them indoors, put them in a garage or storage house. They'll do OK, but not great. The two I have on my front porch go inside my garage during the coldest times. I move them in and out as needed.
You can add humidifiers to your home heating system or buy an electric humidifier. Not only will a humidifier produce a better environment for your ferns and other house plants, it will provide a healthier atmosphere for you and your family.
Otherwise, increase the humidity around your plants by placing them over saucers or trays filled with gravel and water. Always maintain the water level just below the surface of the gravel so the bottom of the pot won't be standing in water.
Some indoor gardeners add charcoal chips to the gravel to keep the water clean and odor free. For best results, replace the gravel periodically or wash it thoroughly when algae starts to develop in the water or on the gravel.
Many people mist their ferns and other houseplants. Mist the plants early in the morning. Apply enough to moisten the fronds well, but not so much that they drip. You can do this several times a day, especially when your heat is running.
Make sure you know what exposure your ferns have on that porch so you will be able to determine what nights they can stay outside this winter.
- Watch for spider mites on houseplants this winter. They thrive in dry air. Isolate infected plants at the first sign of infestation. Several thorough washes with plain water may bring them under control. If not, apply an appropriate insecticide.
- Assess the energy efficiency of your landscape. Do you have evergreen trees or shrubs blocking a window where the sun's warmth would be welcome? If so, consider replacing them with deciduous plants that would let sun in during the winter, but cast cooling shade in the summer.
SID MULLIS IS THE DIRECTOR OF THE UNIVERSITY OF GEORGIA EXTENSION SERVICE OFFICE FOR RICHMOND COUNTY. CONTACT HIM AT (706) 821-2349 OR SMULLIS@UGA.EDU.