Pellaea

( puh - LEE - uh )

At-A-Glance Information

This genus includes small to medium-sized ferns that do well with filtered sunlight. They have detailed foliage and finely divided leaflets, and are commonly called Cliffbrake or Button Fern. These plants can tolerate drier conditions and need well-draining soil to perform well in the landscape. Use these ferns in rock gardens, in crevices of retaining walls or stairways, or in containers on patios or walkways.

Pellaea Species and Varietals

The genus Pellaea is a member of the plant family Pteridaceae, and includes 40 to 50 recognized species. The best growing zones for Pellaea vary depending on the species cultivated. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Pellaea andromedifolia (Coffee Fern, Coffee Cliffbrake)
This species is native to dry, rocky areas of California, southern Oregon, and Baja California. These ferns reach 2 feet tall and wide, and have thin, wiry stems. Leaflets are shaped a little like Coffee beans (hence the common name). These ferns prefer bright, filtered light and are wonderful in native landscapes and rock gardens. Coffee Fern is suited for growing in USDA hardiness zones 8a-11.

Pellaea atropurpurea (Purple Stem Cliff-Brake, Purple Cliff Brake, Purple Cliff Brake Fern)
Great in USDA hardiness zones 5a-9a or Sunset growing zones 2-7 and 14-17, this native of the northeastern US to Guatemala is cold-tolerant and reaches 1-2 feet tall and wide. It has arching fronds, and blue-grey leaflets. Midribs are purple-black, and the fern does best in bright shade and alkaline soil. Needs little water once mature. Great for rock gardens.

Pellaea rotundifolia (Button Fern)
Best in zones 14-17 and 19-24, this Australia and New Zealand native reaches 1-2 feet tall and 2 feet wide, with spreading stalks and rounded leaflets. Foliage is dark green and leathery. Great in mixed container plantings, where its foliage contrasts well against other ferns or flower foliage. Fronds will spill over the sides of pots. Needs regular water for best performance.

Pellaea viridis (Green Cliff-Brake, Green Cliffbrake)
This species is suited for growing in USDA hardiness zones 7b-10b or Sunset growing zones 14-17, 19-24 and H2, and is native to India and Africa. Individual ferns reach up to about a foot tall and just as wide at maturity. Fronds are bright green and have black stems. Great with regular water, but can also tolerate periods of drought well. Use as a groundcover or among boulders in rock gardens. Also good in mixed container plantings. This species is considered invasive in Australia.

Caring for Pellaea

Springtime is the best time of the year to plant these ferns in the landscape, when temperatures have risen above freezing. They need to be situated in bright, dappled shade or partial sun. They prefer to be planted in fertile, well-draining but moist soils in areas with high humidity. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. The ideal soil pH for these ferns is between 5.5 and 7.0. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. Mature Pellaea are considered drought-tolerant, and can get by on rainwater alone for much of the year. During extended periods of drought, water deeply. Ensure that excess water can flow away from the root zone, as these ferns are very sensitive to waterlogged conditions.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Prune off any damaged, diseased, or dead growth in springtime to clean up the look of the plant and improve airflow. Divide plants every 3-5 years or when they are overcrowding their allotted space. For instructions on how to successfully divide these ferns, see the Propagation section below. Pellaea ferns can survive in the landscape for 10 to 15 years before needing to be replaced.

Growing Pellaea in Containers
Pellaea, or Cliffbrake, do well in the ground as well as in containers. Choose a container that has adequate drainage holes on the bottom and is about 2 inches larger than the root ball. Fill the container with well-draining potting mix amended with plenty of organic material, compost, and vermiculite. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly; these ferns grown in containers will require more frequent irrigation than those grown in the ground. Fertilize yearly in early springtime with an application of 1 inch of compost around the base of the fern. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, these ferns will need to be taken out of their pots and divided. For instructions on how to successfully divide Button Ferns, see the Propagation section below.

Propagation

Pellaea, or Cliff Brake, ferns are best propagated via division. This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and/or other organic material, and pots. Division is best done in spring or fall (after the plant has entered dormancy but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best results. To propagate by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the roots. Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots. Once they are untangled, separate the plant into segments, ensuring that each one has at least one thick root section.
Prepare the pot(s) or new planting site(s) with amended, well-draining soil; either bring in new soil or simply amend your existing soil with compost or other organic material to complete this task. Then, plant your divided ferns in soil at the same height as they were previously, and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout.

Problems and Pests

Certain species of Pellaea are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Pellaea ferns can be susceptible to developing issues with the following pests and diseases in the landscape: