Boston ferns (Nephrolepis exaltata) are large, beautiful tropical ferns. Popular in the South, they are often seen gracing the front porches of elegant homes. In the northern parts of the United States, this plant is often grown indoors. The Boston fern is native to tropical areas of the South America and Africa and has long, graceful fronds that can reach up to 6 feet in length.
The Boston fern thrives in soil that is rich, loamy, well draining soil. A high-quality potting mix marked as well-draining (these usually have sand added to them) will work for container ferns. Ferns planted outdoors should have sand and organic material, such as leaf mold, worked into the soil before planting.
These ferns enjoy humid conditions and barely moist soil. Water when the top layer of soil dries out down to about an inch or so. Standing water can rot the roots of the plant. Potted Boston ferns should contain drainage holes. Empty the catch tray after the plant has finished draining. Always water with lukewarm or room temperature water, and not cold water from the sink. In addition, provide humid conditions for your Boston fern by placing it on a tray filled with water and pebbles, or by misting it daily with lukewarm water.
Light and Warmth
Boston ferns can only be planted outside in the United States in USDA growing zones 9 through 11. In other areas, the fern should be grown in a container and brought indoors when cooler weather arrives. The Boston fern will not survive freezing temperatures. This plant enjoys partial shade or filtered sunlight. Direct sunlight can burn the fronds, turning them black.
Boston ferns are not heavy feeders. In addition, their roots are delicate, so overfertilizing can burn them. Use a balanced (10-10-10), slow release, water soluble fertilizer in granular form. Feed the fern every other week with half the recommended dose. If the leaves start to turn yellow, increase the feedings to once a week.
Ferns, including the Boston fern, are often plagued by insect pests. Mites, scale and mealybugs are all common problems on Boston ferns. Check often for these tiny insect pests and dislodge them by hand or with a strong blast of lukewarm water. If a heavy infestation occurs, use a pesticide that is marketed for use on ferns.