How to Grow and Care for a Japanese Holly Fern, a Glossy Green Houseplant That Requires Minimal Upkeep

If want to add a low-maintenance houseplant to your collection, Japenese holly ferns should be at the top of your list. Known formally as Cyrtomium falcatum 'Rochfordianum,' these beautiful perennials grow mini leaflets with a glossy green finish; over time, the plant can reach up to 2 feet in height. With the proper care, you'll help this houseplant thrive, so you can enjoy it for years to come.

Fast Facts

• Common Name: Japanese Holly Fern
• Botanical Name: Cyrtomium falcatum 'Rochfordianum'
• Plant Type: Perennial
• Hardiness Zone: 6 to 9
• Mature Size: 18 to 24 inches tall, 24 to 36 inches wide
• Sun Exposure: Full or partial shade
• Soil: Well-drained
• Native Area: East Asia

How to Pot Japanese Holly Ferns

You'll know a holly fern when you see one: They have long, serrated fronds (another name for their divided leaves), says Chad Massura, the CEO and founder of Rosy Soil, an eco-friendly potting mix company. "These decorative ferns make a great houseplant because they thrive in containers and are relatively care-free," he says.

As for how to pot these laid-back beauties? "Indoor potted ferns can be planted at any time of the year; if your potted plant is slated for the outdoor patio, reduce stress with a spring planting, after the threat of frost has passed and before the summer heat sets in."

1. Plant the holly fern so the base of it is level with the soil surface in a container with good drainage. (Planting the ferns too deep can cause the base to rot, and planting them too shallow can leave the roots exposed and vulnerable to drying out, says Massura.)
2. Be sure to pack the soil, since these plants need to potted tightly to thrive, says Kate Ferguson, the co-founder of Flourish, a plant food brand. "They have large, spindly root balls that may even look root bound in their pots, but they prefer to grow this way in containers," she says.
3. Water the holly fern evenly until the soil is wet, but not soaked.
4. Place the container in a bright area out of direct sunlight.

How to Care for Japanese Holly Ferns

Even though Japanese holly ferns are low-maintenance, establishing a care routine is still important. If you want your plant to reach its mature height and sprout leaflets, provide it with the light, soil, water, and fertilizer it needs and prune when necessary.

Light

"These plants prefer dappled indirect light and can handle the shadier corners of your home," Massura says. "With that said, ferns in low light conditions grow dramatically slower than those in filtered light, so manage your expectations accordingly."

Soil

For optimal growth, make sure the soil is evenly moist—and do your best to prevent it from drying all the way out. "The key to success is using a high-quality potting mix that can retain moisture without becoming dense and soggy, conditions that lead to root rot," he says. "For an earth positive boost, ditch peat-based potting mixes and look for soils that prioritize ingredients like biochar and compost, which deliver the perfect combination of water retention and drainage."

Water

Routine watering is necessary for this plant's health. Water until the soil is moist, but not soaking wet, notes Megan McConnell, plant information director at Monrovia, a home gardening company. Not sure when to apply more? "A good check is to touch the top of the soil, and if it feels dry, water slowly and deeply until excess water drips from the drainage holes," says Massura, who suggests watering over a sink or tub to avoid a mess. "Aim to water your indoor fern at least once every ten days, although this depends on your pot size: larger pots require less frequent watering than smaller pots."

Water your holly ferns even more in the warmer months and as soon as the top inch of soil dries out during the rest of the year, explains Ferguson. Water retention and absorption will depend on the temperature and humidity in your home, quality of soil, and other factors, so always check the soil to make sure it is moist enough, she notes.

Fertilizer

Fertilize your fern once a week in warmer months and once every two to three weeks in colder weather, notes Ferguson. "Flourish Organic Plant Food is a great option because the macronutrients combined with microbes will help invigorate the soil biome and mimic the nutrient-dense forest floor where ferns thrive," she says. "Adding a microbe-rich fertilizer to your ferns will also help the ferns to retain water and encourage root hair development to absorb and break down nutrients in the soil."

A liquid fertilizer like fish emulsion is another helpful option, since it is high in nitrogen and nutrients to help the fern reach its full size, adds Massura.

Pruning

Pruning holly ferns is simple: Cut off any fronds that are dried up or damaged with scissors, says Massura. "It is generally best to do this in the late winter or early spring, before the plant starts to actively grow again," he says.

How to Propagate Japanese Holly Ferns

Unlike many other popular houseplant varieties, ferns don't produce seeds. They are propagated through the spores found on the underside of their fronds, says Massura.

Follow Massura's best practices to propagate your holly fern:

1. Collect mature spores by cutting a few fronds and placing them, spore side down, onto wax paper. (Spores start off green and change over time to brown when they mature, he says.)
2. Wait a few days for the spores to release a dust-like powder, which can be placed on damp potting soil and covered with plastic wrap to maintain a moist environment.
3. After a month or two, remove the plastic wrap and mist regularly. If you are successful, small green plants will begin to sprout.

If you want to use a different (and easier!) replication method, follow Massura's best practices for rhizome division:

1. When ready, remove the fern from its pot and dust off some soil from the roots.
2. To avoid stress, water your fern a day ahead of the division.
3. Locate a piece of the fern's horizontal rhizome with vertical roots attached and at least a few bright green fronds.
4. Use a knife to gently cut it free.
5. Replant the parent fern into its original pot and plant the rhizome cutting into a new container or pass it off to a friend.

How to Repot Japanese Holly Ferns

You can repot your holly fern in the spring before it starts growing intensely in the summer. It's recommended to use a container with good drainage and to make sure the crown of the plant stays just above the soil line, says McConnell. "They should only be repotted once the roots begin to grow regularly through the drainage holes in the nursery pot or if the foliage has increased significantly and mature leaves are starting to die more quickly due to lack of nutrients," says Ferguson.

Follow Massura's best tips for repotting:

1. Gently remove the plant from its container.
2. Loosen any tangled roots with your fingers before placing it into a new pot.
3. Aim to have all roots facing down before you cover them with fresh potting mix.
4. Ensure the plant's crown is slightly above the soil line to prevent rot.

Common Problems With Japanese Holly Ferns

Although holly ferns are known for being easy to care for, there are a few problems to watch out for as you grow your own.

Drying Out

When this plant lacks moisture or nutrients, its leaves can dry out, says Ferguson. To remedy this issue, increase the watering frequency and add a nutrient- and microbe-dense fertilizer.

Pests

Keep an eye out for pests. "Pest concerns with ferns are generally due to overwatering or lack of proper drainage and decomposing material in the soil, attracting fungus gnats or other pests," Ferguson says.

The most common pests are scale bugs, which look like yellow oval bumps on stems and leaves. "They can stunt plant growth and cause leaves to turn yellow," Massura says. "You can control infestations by gently spraying or wiping leaves down with an approved pesticide or try an at-home remedy of water and dish soap." Note that plant spores and pests can look similar; the former pop up on the underside of fronds and are a normal part of growth (they should not be removed).

Root Rot

If your pot sits in water, root rot can set in. A pot with proper drainage will resolve this issue. "Small fungal spots may appear on the leaves if water is allowed to sit on them," McConnell says. "Avoid overhead watering, or water in the morning to allow the leaves to dry during the day." If you notice fungal spots growing on the fronds, consider using a fungicide or cutting the watering schedule.