Boston ferns can lose their color in a dry environment.
The Boston fern (Nephrolepsis exaltata "Bostoniensis") originated from a species native to Florida and the Pacific Rim. Depending on the variety, its long, arching fronds or leaves grow up to 10 inches to 4 feet long. Also known as the sword fern, the Boston fern grows well in a hanging basket in moist, aerated soil.
Features
Boston ferns require indirect light and humid conditions, with a relative humidity of at least 30 to 50 percent. Indoor plants prefer daytime temperatures between 65 and 75 degrees Fahrenheit and nighttime temperatures between 55 and 65 F. According to the University of Florida, Boston ferns grow well outdoors or in greenhouses in temperatures between 65 and 95 F.
Effects
An indoor environment may be too dry for a Boston fern; insufficient moisture can cause grayish fronds and slow growth. According to the University of Arkansas, an outdoor Boston fern that overwinters indoors may drop leaflets as it adjusts to the darker, drier conditions.
Solution
To revive your fern, place it near a humidifier and mist the fronds with room temperature water. Place the fern's container inside a larger pot lined with moist sphagnum moss and keep the moss and soil consistently moist. You can remove unhealthy fronds and place an overwintering Boston fern on a sheet near a south-facing window.
