Ferns are a common outdoor landscaping plant, especially in shaded areas where they can thrive. Ferns are hardy and low maintenance plants that can be grown indoors or outdoors. One of the facets of caring for outdoor ferns is trimming or pruning them to keep the tidy. Ferns also need trimming when they become infested with disease or insects. The plants are easy to trim because separate fronds are easy to grasp.
Cut back old, faded-looking fronds around the base of the fern with sharp pruning shears. Do this in the late winter or early spring before new growth emerges, and cut them back to the ground.
Cut the removed fronds into small, 1-inch pieces. Spread the cut leaves around the base of the plant as mulch.
Trim off any fronds that show signs of disease or insect infestation. Cut them back to the base of the plant. This can be done at any time during the year. If the entire plant shows signs of damage, cut the whole thing back to the ground. It will reshoot.