From Victorian parlors and front porches until today, ferns prove a popular houseplant choice; not surprising, given their gracefully drooping fronds and lush appearance. Summer care is fairly simple; a tropical plant often growing on tropical rainforest floors, ferns readily grow outside in the humidity and warmth. Taking care of any "summer" fern in winter is a little more difficult, but a few simple steps can keep it alive until summer arrives again.
Locate your fern indoors in a cool bedroom, kitchen or even the bathroom, as long as there is fairly bright but indirect light -- within 4 to 7 feet of a south-facing window, or closer to a northern or eastern window, is suitable. Direct sunlight is harsh on a fern, especially in winter when the plant is dormant. Avoid places where your fern is exposed to a heat register or other drafts, as well.
Place your fern on a plant stand or hanging in a basket, according to your preferences and situation. Consider spreading a blanket, sheet of plastic or towel under and around your fern; they are notorious for shedding fronds in winter, and this will make clean-up easier.
Clip dead fronds off the fern as they turn brown and dry out. Fronds that begin to die will not grow back, so cutting them helps maintain the fern's appearance. Use sharp kitchen scissors and cut at the base of the frond.
Maintain room temperatures of around 50 to 55 degrees Fahrenheit. This is in contrast to summer months, when ferns thrive at temperatures ranging from 65 to 85 degrees, with temperatures cooling about 10 degrees at night. Avoid allowing the fern to experience temperatures below 40 degrees, which will kill it.
Water your fern occasionally, depending on how humid or dry your house is (gas heat especially tends to be very drying). Do not allow a fern to stand in water or be soggy. Stick your finger into the plant and slightly into the soil; if it feels dry to the touch, water it. Consider misting it with water once or twice a week as well. (A fern receiving adequate water has a rich color, but fading fronds indicate a lack of water.) Begin watering more around February, when new fronds begin to appear.
Avoid fertilizing your fern during the winter. Fertilizer should be applied, at half-strength, from April to September only. Newly re-potted ferns should not be fertilized at all until new growth begins, which may take several months.
Divide your fern late in the winter (around February or even March) if it is becoming overgrown for the pot it is in. Remove it from its pot, cut through the rhizomes (roots), and divide into new containers filled with a 50-percent peat moss soil mix. Avoid moving the same plant to a larger container more than every few years, as ferns can reach 5 feet in size and quickly become unwieldy. Division is a much better strategy.
Dunk your fern underwater in a bathtub, holding it under until all air bubbles stop bursting to the surface. This ensures all the roots get watered, which is critical.
Begin adjusting your fern to outside living in the spring, once the last frost is over. Take it outside for a couple hours a day, slowly increasing time until it is used to being outside. Leave it outside full time through the rest of the summer, until time for the first frost, then winter inside again.