How to Grow Ostrich Ferns
Reaching heights of up to 6 feet tall and producing curling, feathery fronds, ostrich fern (Matteuccia struthiopteris) is a perennial species that thrives in cool, shaded areas. It requires minimal maintenance and care, and is rarely bothered by pests or diseases. The fern often spreads, forming dense colonies when planted in ideal growing conditions.
Choose a Shady Site
Ostrich fern is hardy in U.S. Department of Agriculture plant hardiness zones 3 through 7, where it prefers partial and full shade. A wooded area, the north side of a building or a shady riverbank or pond side are ideal locations for the plant. It does best in naturally cool climates and suffers when grown in humid, southern U.S. regions. Because each ostrich fern can grow 5 to 8 feet wide, provide at least 5 feet of space between each fern and other plants. Transplant an ostrich fern by digging it up carefully in early spring, leaving plenty of room around its crown -- where its above-ground and below-ground parts join -- to avoid disturbing its roots. Replant the fern so that soil completely encloses its root ball, but don't place the fern so deeply that soil gets in its center, from which its fronds or stems grow; soil in that location may cause rot.
Add Organic Material to Soil
Ostrich fern tolerates a wide variety of soil types, though it looks its best in well-draining soil generously enhanced with organic matter. If your location has light, sandy soil or heavy clay soil, mix a 2-inch-thick layer of organic material, such as composted pine bark, with the top 10 inches of the soil before planting. Rather than just mixing the organic matter into each planting hole, mix the material into the whole planting bed so that water doesn't fill the hole and cause root damage to the plants.
Water frequently -- at least once each week unless it rains -- to keep each ostrich fern's soil moist at all times. Do not allow the soil to dry out completely; err on the side of too wet rather than too dry because ostrich fern tolerates wet soil. Applying a 2- to 3-inch-thick layer of organic matter such as leaves or pine straw on the soil surface -- but not touching the plants -- in spring and fall helps retain moisture in the soil. In a wooded area, the ferns receive some natural mulch from fallen leaves and evergreen needles.
Ferns are sensitive to fertilizer, though they can benefit from a light application in spring, right after their new fronds begin to emerge. Use a controlled-release, granular, 14-14-14 fertilizer, spreading 1/8 cup of it uniformly on the soil surface per 10 square feet, avoiding getting it on the ferns and other plants. Till it into the top 1/2 to 1 inch of the soil very lightly if you can avoid damaging the ferns' roots or rhizomes. Store unused fertilizer in a cool, dry place away from children and pets.
Michelle Wishhart is a writer based in Portland, Ore. She has been writing professionally since 2005, starting with her position as a staff arts writer for City on a Hill Press, an alternative weekly newspaper in Santa Cruz, Calif. An avid gardener, Wishhart worked as a Wholesale Nursery Grower at Encinal Nursery for two years. Wishhart holds a Bachelor of Arts in fine arts and English literature from the University of California, Santa Cruz.