During the Victorian Era ferns were extremely popular as indoor plants, and this popularity continues today. Ferns can also be found growing in shady areas throughout the garden. They are non-flowering plants that grow from spores (as opposed to flowering plants, which are grown from seeds). The spores are located on the back or underside of the frond/leaf. Ferns have specific temperature, light, humidity and watering requirements.
Ferns are native to the subtropics or the tropics. However, they prefer temperatures on the cool side with high humidity levels. When grown indoors temperature recommendations are: nighttime temperatures around 60 degrees Fahrenheit, and daytime temperatures not exceeding 72 degrees Fahrenheit. When grown outdoors they will need to be planted in a deeply shaded area or in a protected site that has a northern exposure (next to a house or other structure). They should never receive full sun during the summer months.
Humidity and Indoor Plants
Ferns prefer a humidity level of 40 to 50 percent. Most homes do not have such high humidity levels. You can increase the humidity level in the room by using a humidifier or you can choose to increase the humidity level just around the fern. To increase the level of humidity around a fern place the fern in a saucer that contains gravel and water. You do not want the pot to stand in water; the water level should be kept below the top of the gravel. To avoid an odor and to keep the water clean, place some charcoal chips in with the gravel. Also, replace or clean the gravel every three months. Some ferns will require misting during the winter months.
Watering Indoor Plants
Water requirements vary due to fern size, fern type, the soil, and the temperature and light in the room. Ferns are just like other house plants--you will need to feel the soil and judge the appearance of the plant to determine when to water. If ferns are over-watered or under-watered they will begin to shed their leaflets.
Light Requirements of Indoor Plants
Light requirements can vary according to the type of fern. Some require low to medium light (holly ferns), and some need low to bright light (bird's nest ferns). A window with a northern exposure suits a large number of fern species. Windows that have an eastern or western exposure will need to have a 50 percent reduction in light during the summer months, as stated by the University of Georgia Cooperative Extension. To cut down the amount of light entering the room you can add a sheer drape or curtain to the window.
Landscape ferns require well-drained sandy or humus soil. They prefer shady areas with indirect light. You should not plant them in an area that receives direct afternoon sun. Fern clumps can be divided after the first frost and through the month of November.