Q. How do I care for my Boston fern?
Nephrolepis exaltata 'Bostoniensis' (Boston fern) is characterized by many sword-shaped, arching fronds divided into many small leaflets, giving the plant a feathery appearance. The fronds of these popular houseplants can grow up to 4-6 feet long, often arching out and over from hanging baskets or pots on pedestals.
Nephrolepis is a relatively tough fern. It has a higher tolerance for light than other ferns, thriving in bright, indirect light. Low light conditions cause the fern to continually shed leaves. Conversely, a yellowish-green, bleached-out appearance is a symptom of too much light--this plant cannot tolerate the hot summer sun.
Although it is more tolerant of occasional dryness than many ferns, keeping the plant's root ball moist is important, so always water thoroughly. Since humidity is also important, at temperatures above 70°F increase humidity by standing the pot on a tray of damp pebbles and misting the plant regularly. If the humidity is too low, leaves will turn yellow. When growing indoors, normal room temperatures are suitable; the minimum tolerable temperature is 50°F. If the temperature falls below 55°F for more than a day or two, allow the top 1/3 of the potting mixture to dry out between waterings.
Ferns can be grown in either a standard peat-based potting mixture or 1/2 soil-based mixture and 1/2 leaf mold. When the roots have grown to fill the pot, repot in spring to a pot only one size larger. Or remove the plant from the pot in spring, trim away some of the outer roots, and replace the plant in the same pot after cleaning it. To fertilize, use standard liquid fertilizer every 2 weeks for plants growing in a peat-based potting mixture, or every 4 weeks for plants in a soil-based mixture.
They are easy to propagate. Numerous slender runners grow out of the base of the plant; at the end of these runners grow many plantlets, which can be removed, planted in a 3-inch pot, and treated in the same way as a mature plant. Alternatively, Boston fern can be divided at repotting time into two or more smaller plants.
Keep your your fern away from drafts. Remove old, browning leaves as they appear. Occasionally a long, less segmented (less feathery) frond will develop. Cut it out immediately, so that these less appealing fronds do not take over the plant.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service