Ferns are prehistoric plant forms that are prized for use as indoors and outdoors. While most ferns are tropical or subtropical in origin, they make up a very large plant family--there are more than 12,000 species, according to the University of the West Indies. Ferns typically grow in nutrient-rich woodland soils, and are not heavy consumers of synthetic fertilizers. They can easily be burned or shocked by fertilizers, so gentle slow release formulas are preferred for both hardy and tender tropical ferns in order to prevent over fertilization.
Fertilize fern plants in the spring just as new green growth begins to emerge and unfurl.
Feed your ferns with a slow release fertilizer with a balanced and guaranteed analysis of 14-14-14.
Sprinkle the recommended amount of grains around the base of the plant evenly, keeping a few inches away from the center stems and extending out to or just past the drip line.
Water the fertilizer to wash it down into the top half-inch of soil. Water liberally to keep the soil evenly moist, which will help distribute the fertilizer nutrients throughout the soil.
Repeat the application each year or as recommended on your product label, but always err on the side of less fertilizer, not more.