Royal fern, Osmunda regalis, are huge specimens for the shady landscape. Royal fern is a perennial that grows in partial to full shade in Zones 3-9. Find facts and information on growing royal fern.
Royal fern reaches heights and widths of 6 feet. It prefers shade, shelter from the midday sun, and fertile, well-drained soil. Plants tolerate wet soil as well. You will notice bright green fronds that reach 3 feet long in spring, and lengthening to 6 feet long in summer. Royal fern has fibrous roots that are visible above ground and create interest. They are used as osmunda fiber in orchid potting mixes.
Plant Osmunda regalis in odd-numbered groups in the large border, as a tall ground cover in the woodland or at the water’s edge, or as a focal point in a large container planting. Good companions include goatsbeard, ‘Superbs’ Chinese astilbe, bugbane, and ‘Francis Williams’ hosta.
Care of Royal Fern
Plant 3-6’ apart in spring or fall. Apply slow-release granular plant food at time of planting if desired. If planting in a wetland, or near water, avoid fertilizers and chemical pesticides to prevent chemicals from leaching into water bodies. Till in organic matter to create deep, humusy, fertial soil.
You can also provide 3” of vegetative mulch around, but not touching, the plants in summer and winter to help retain soil moisture and add organic matter to the soil. Always try to maintain moist soil for your plant.
If an irrigation system is used, maintain deep infrequent waterings and aoid delivering a light sprinkle every day. Royal fern may be pruned back in fall once frost withers the foliage.
Propagation is done by division in spring or fall by digging around the rhizomes and lifting. Use a spade to cut throught the roots and divide portions. Plant only healthy portions with good root system.
Rust is sometimes a problem, but otherwise, the fern is pest and disease free.
The cultivars ‘Crispa’ and ‘Cristata’ have crested tips. ‘Purpurescens’ has purple-stained fronds in spring, and ‘Undulata’ fronds have wavy edges. Interrupted fern (O. Claytoniana) tolerates drier sites and is hardy in Zones 4-8.