North American ferns range from small, lacy maidenhairs to 15-foot-tall tree ferns. Wherever you live, there are some to add a touch of green to a shady nook. Many can survive only in their native environments; others will live almost anywhere. Many are protected bylaw; do not gather wild ferns unless you know that they are not among the protected ones.
A reputable dealer or your Cooperative Extension Agent will help you choose ferns suited to your soil, climate, and garden conditions. Soil pH is critical; lime-loving ferns simply will not grow in acid soil, nor will acid-loving ones grow in alkaline soil. Once established, however, most ferns will thrive for years with little care. Place large plants-such as shield, lady, cinnamon, deer, or royal ferns in the center of the bed. Surround them with such medium-size ones as hardy maidenhairs, hart’s-tongues, Japanese painted ferns, male ferns, and sensitive ferns. Use polypodys, maidenhair spleenworts, and other small, spreading ferns as a border. Incorporate bulbs and wildflowers to brighten the bed in spring.
Planting and care
Most ferns need loose, well-drained soil rich in humus. Before planting, dig or rototill the bed to a depth of at least 9 inches. Work in a 3-inch layer of leaf mold or compost and a sprinkling of bonemeal. Set each fern so that its crown is level with the soil; then firm the soil around it. Water thoroughly. Apply an organic mulch, such as dry leaves or peat moss, to retain moisture and discourage weeds.
Add mulch in fall; leave dead fronds on nonevergreen species. In spring, remove dead fronds and all other material that cannot be crumbled by hand. Do not use rakes or forks; fern roots are easily damaged. Pull weeds, and add fresh mulch. Fertilize occasionally with a high-nitrogen plant food diluted to half strength. In dry weather, water deeply one to three times a week to keep soil moist.