How to Plant and Grow Japanese Holly Fern

The aptly named Japanese holly fern produces long fronds with sawtooth leaflets that resemble holly leaves. Indoors (and in mild outdoor climates), the glossy, deep green foliage of Japanese holly fern stays evergreen throughout the year.

The easy-to-grow fern is an import from southern Asia and is not to be confused with Polystichum braunii, a native plant commonly called Braum's holly fern. As a houseplant, Japanese holly fern is low-maintenance and less fussy about humidity than other indoor ferns. Outdoors, Japanese holly fern is often found in wildlife, woodland, rock, and shade gardens. Its vase-shape growth habit and stout form make it an excellent border plant or backdrop for colorful annuals and perennials. In natural settings—where windblown spores can produce new plants—the rich emerald color of the Japanese holly fern makes it a beautiful option for the understory of shady trees.

Where to Plant Japanese Holly Fern

Japanese holly ferns are tough, durable ferns that tolerate a wide range of light and soil conditions. It grows 2 to 3 feet tall and wide in moderate to dense shade in zones 6-10 (and sometimes zone 11). In zones where this plant is not winter-hardy, site it in a sheltered location.

Japanese holly ferns are native to the moist hardwood forests of southern Asia. So, they are perfectly at home in woodland gardens, shade gardens, and tree-filled landscapes. Japanese holly ferns prefer moist conditions but do not tolerate soggy soil. They contribute rich texture and evergreen foliage to shadowy corners or areas where sun-loving plants won’t grow.

How and When to Plant Japanese Holly Fern

Plant Japanese holly fern in the spring (after the last frost) to reduce plant stress. They prefer fertile, well-drained soil, so make any necessary amendments a few weeks before planting. When ready, dig a hole slightly more shallow than your plant's container. While the plant is still in its pot, water it deeply and allow the excess water to drain away. Remove the plant from its container and place your plant in the hole. Backfill the hole and tamp down the soil leaving the crown of the roots slightly exposed. If you are planting more than one fern, place them approximately 18 to 24 inches apart.

Japanese Holly Fern Care Tips

Japanese holly fern is an easy-to-grow, shade-loving plant that is tough, pest-resistant, and perfect for shady locations. It is, however, capable of self-spreading via spores. Be cautious of planting it in areas where it may displace native plant life.

Light

Japanese holly ferns grow best in full shade but will tolerate some morning sun. Avoid planting your fern in full afternoon sun as it will likely scorch.

Soil and Water

Japanese holly ferns prefer acidic to neutral soil (ideally 6.0 to 7.8 pH) that is evenly moist, fertile, and well-drained. Avoid planting spots where the soil stays wet for extended periods. Wet soil encourages root rot—which is especially detrimental during winter months.

Water your fern whenever the soil feels dry to the touch and more regularly during dry periods.

Temperature and Humidity

Whether grown indoors or outdoors, Japanese holly ferns prefer 50-70% humidity and an environmental temperature between 50˚ and 95˚ Fahrenheit—as long as ample shade is provided. In mild climates, the glossy, deep green foliage of Japanese holly fern stays reliably evergreen. In colder climates, Japanese holly ferns are deciduous and may lose color and foliage over the winter months.

If you live in a colder region, cut your Japanese holly fern back to ground level in early spring (before new growth begins). In Zones 6 and 7, cover Japanese holly fern with a layer of straw mulch in winter to protect it from extreme temperatures.

Fertilizer

Feed your Japanese holly fern with a balanced, slow-release fertilizer in the spring (as new growth emerges) and again in late summer.

Pruning

Japanese holly ferns require no pruning, but you can remove damaged, diseased, or dried-up fronds as needed. You can also cut back winter-damaged fronds to ground level in the spring before new growth emerges.

Potting and Repotting

Japanese holly ferns tolerate low humidity, which makes them great houseplants. Happy indoor ferns will eventually grow about 2 feet tall and wide, so plan accordingly.

To plant an indoor Japanese holly fern, pot your fern in a 12- to 18-inch container filled with a good-quality potting mix and place it in a room with medium or indirect light. Avoid sunny windows as direct sunlight can scorch this plant's foliage. 

When grown as a houseplant, Japanese holly ferns need regular watering to maintain moist (but not soggy) soil. Feed your fern with a balanced liquid fertilizer (diluted by half) every month from spring through fall.

Japanese holly ferns grow most quickly in the summer, so plan to repot yours every couple of years in the spring before its summer growth spurt. Choose a pot with ample drainage that is just 1 to 2 inches larger than the previous one. Overly large containers could lead to soggy soil. When you repot your fern, make sure the plant's crown sits just above the soil line to avoid rot. You can also divide the plant in spring when it outgrows its container.

Pests and Problems

Japanese holly ferns are fairly resilient, but scale, mites, mealybugs, slugs, and snails can occasionally be a problem. When checking for these issues, don’t mistake the spores on the undersides of the leaves for pests.

Fungal spots and root rot can also be a problem in poorly drained or overwatered soil.

How to Propagate Japanese Holly Fern

The simplest way to propagate Japanese holly fern is via rhizome division. In the spring, remove your fern from its pot and use your fingers to loosen the soil from the roots. Locate the rhizome in the center of the root ball and separate it into two or three parts, each with some roots and healthy, green fronds attached. Replant each section in a separate pot.

You can also propagate Japanese holly fern by collecting spores and placing them on the surface of some damp potting mix. Wrap the container with plastic wrap and spritz the soil regularly to keep it evenly moist. If you are successful, your spores should begin to sprout in 2 to 3 months.

Types of Japanese Holly Fern

Butterfield's Japanese Holly Fern

Butterfield’s Holly Fern (Cyrtomium falcatum 'Butterfieldii') grows about 18 inches tall in zones 7-10. It features glossy, dark evergreen fronds with deeply-toothed, serrated leaf margins.

Korean Lace Dwarf Holly Fern

Cyrtomium falcatum ‘Eco Korean Lace’ (Korean Lace Dwarf Holly Fern) grows in small clumps that stretch only 6 to 15 inches wide. They are hardy in zones 7-9 and feature glossy green leaves.

'Rockford' Holly Fern

‘Rockford’ holly fern (Cyrtomium falcatum 'Rochfordianum') is a vigorous holly fern cultivar that is hardy in zones 6-11 and evergreen in zones 9-11. It typically grows 12 to 24 inches tall and wide and features serrated leaflets.

Companion Plants for Japanese Holly Fern

Deadnettle

Deadnettle is a ground-hugging perennial that thrives in shade and a wide variety of other growing conditions. The plant is easy to grow in zones 4-8 and brings lots of visual interest to shady corners with a carpet of colorful foliage and long-blooming flowers. Some varieties of deadnettle—like spotted dead nettle (Lamium maculatum) or purple deadnettle (Lamium purpureum)—are considered invasive, so check with your local garden extension service before planting it in spaces where it could run wild.

Heartleaf Brunnera

Heartleaf brunnera is a low-growing, clump-forming perennial that boasts clouds of tiny, sky-blue flowers from early to midspring in zones 3-8. Like Japanese holly fern, heartleaf brunnera thrives in locations with partial shade and moist but well-drained soil. The plant does not have any specific pH requirements, so it adapts well to acidic, neutral, and alkaline soil.

Hosta

You can’t talk about showstopping shade plants without talking about hostas. Hostas offer lush foliage and are easy to care for once established. They also come in a wide variety of shapes and sizes—from dwarf varieties that measure just 12 inches tall to grander versions that stand 2 to 3 feet tall and wide. Like Japanese holly ferns, hostas love fertile, moist, well-drained soil and partial to full shade. They are hardy in zones 3 to 9.

Ligularia

With its showy burgundy to green leaves and golden summer flowers, perennial ligularia makes a stunning addition to shade gardens. Ligularia is hardy in Zones 4 to 9 and tends to grow 3 to 8 feet tall when grown in consistently moist, rich soil. It likes a little more sun than Japanese holly ferns, so plant it on the sunny side of a garden spot and let its dramatic foliage block out the sun for shade-loving companions.

Wild Ginger

Wild ginger (Asarum spp.) is a low-growing perennial that (like Japanese holly fern) thrives in moist, shady places. This stemless plant features dark green heart-shape leaves with visible veining and cup-shape purple-brown flowers that tuck in among the foliage each spring. Despite its name, wild ginger is not a relative of culinary ginger, but its leaves and roots smell like ginger when crushed. Wild ginger is hardy in zones 3-8 and spreads slowly by rhizomes to create a lush groundcover in shady areas. It's also deer-resistant.