Autumn fern at Atlanta Botanical Garden

Autumn ferns in Container planting

Ferns are fine textured lacey-leaf groundcovers. Many kinds of ferns add a tropical accent to the shade garden. Autumn fern (Dryopteris erythrosora), aka Japanese wood fern,  has evergreen or semi-evergreen arching foliage, depending how cold it gets in winter (USDA hardiness zones 5 to 8).

Its common name is misleading. Best frond colors are in spring; the fronds unfurl with a coppery-red or pink tint and gradually fade to bronze-green after 4-6 weeks. In late summer, bright-red spore clusters (sori) appear on the frond’s underside. In fall, fronds take on more of a russet tone.

Most winters autumn fern stays evergreen in zone 8. It grows happily beneath large shade trees or in dry soils. In the first year start off with plenty of water, compost, and mulch to get the root system established. It prefers an evenly moist soil, and mildly acidic soil pH between 5.5 and 7.0.

In early spring emerging fiddleheads (fronds) unfurl to form a vase-shaped clump, 18-30 inches tall and wide depending on age. At planting, space this fern 16-18 inches apart for dense coverage. Indifferent to heat, humidity, and cold, this moderate shade lover excels in full morning sun in zone 5 and 6, but wants more shade in southerly climes.

From then on, autumn fern performs season after season with little additional care. It has no serious pest or disease problems and soil nutritional needs are minimal. Applying 2-3 inches of leaf mold is almost equivalent to feeding with slow release fertilizer.

The cultivar ‘Brilliance’ grows 2 feet high and wide and offers long seasonal impact. Its frond’s color is exceptional, that is, the upper surface has a rich coppery tint and high gloss which holds through most of the summer and turns russet in autumn.