How to keep indoor potted house ferns healthy

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Last Updated: 
December 29, 2006

CORVALLIS - Are your house ferns looking sickly? Ross Penhallegon, a horticulturist with the Oregon State University Extension Service, says there are a number of things you can do to keep them looking healthy.

Start by keeping ferns in cooler-than-average rooms.

Ferns love and need humidity. Add extra humidity by lightly misting the plants daily or placing the pots on a pebble tray filled with water. Natural evaporation will increase humidity around the fern. Avoid setting ferns near sources of drafts, heat, or extreme colds such as near doors, appliances, wood stoves and furnace ducts.

Water ferns only as needed. Check the soil before adding water. Thoroughly moisten entire soil area in the pot and pour off any excess that drains through. Do not let the plants sit in water for any length of time or the fronds will yellow or die-back. Dry frond tips may indicate a lack of water and low humidity. If you do a lot of heating in the winter, keep the ferns on a lower shelf rather than hung high near the ceiling.

Don't be heavy-handed with fertilizer. Ferns require very little. Feed ferns lightly about three to four times per year with a water-soluble, low nitrogen fertilizer. If fronds yellow, increase to four or five times per year.

To control and prevent pests on ferns, wash the plant completely with a water spray. Be sure to not mistake the brown fuzzy-looking spores on the underside of the leaves for a problem – they are a natural part of the plant, not pests or disease.

Avoid using pesticides on ferns, as some ferns are quite sensitive to chemical insecticides.

Author: Carol Savonen