Pteridium

pteridium

( ter - ID - ee - um )

At-A-Glance Information

Commonly called Bracken or Brake, this genus of ferns includes species that need full sun to partial shade and little to regular water to perform well in the garden. These ferns grow naturally in open forested areas or disturbed soils and are one of the world's most abundant ferns. Fronds can reach 2-7 feet tall and are intricately divided. Species are native to temperate and subtropical regions of Eurasia, North America, and Africa. These ferns are not recommended for smaller landscapes, as they aggressively spread via deep underground rhizomes. They are occasionally used in large-scale landscape settings, and can be utilized to stabilize banks and sloped areas while providing cover for invertebrates and small woodland animals. Take care when planting these ferns in the landscape, as plant parts are toxic to livestock if ingested.

Pteridium Species and Varietals

The genus Pteridium is a member of the plant family Dennstaedtiaceae and includes 11 species. Bracken Ferns grow well in USDA hardiness zones 3-10 and can survive winter freezes down to -40 degrees Fahrenheit. To find your zone, click here: Zone Map.

Pteridium aquilinum (Pasture Brake, Brake, Bracken, Eagle Fern, Common Bracken)
This herbaceous perennial fern is winter-deciduous, and forms large, roughly triangular green fronds. They grow from rhizome and form large colonies of genetically identical fronds that have been found to be as many as 650 years old. These ferns reach up to 3 to 6 feet tall when mature and produce rhizomes that can spread underground to reach up to 50 feet long. Pasture Brake is considered invasive in Britain, Ireland, regions of southern Africa, and parts of North America.

Pteridium esculentum (Bracken Fern, Austral Bracken, Bracken)
This species of ferns grows from creeping rhizome roots and produce triangular green fronds that can reach up to almost 7 feet tall. It is native to a widespread area of the Southern Hemisphere. The roots of these ferns were once cultivated a food source for the Māori, who called the roots 'aruhe'. It is now known to be carcinogenic and is no longer widely consumed. These ferns are considered invasive in New Zealand and Australia.

Caring for Pteridium

Pteridium ferns are known for their invasiveness in landscapes, spreading by aggressive underground rhizome roots. Before planting these ferns, it is recommended that a barrier is installed around the planting area to discourage their spreading tendency. Plant Pteridium in a space in the landscape that receives partial shade to full sun; ideally, they appreciate at least 6 hours of sun each day. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 4.0 and 6.5 (acidic to neutral). 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. 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. At maturity, these plants have low to medium water needs, and can even become drought tolerant in partial shade. 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. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season. The individual rhizomes can survive in the landscape for decades (up to 3/4 of a century) before fading. Plants will form spreading colonies, however, providing new ferns for the landscape indefinitely.

Propagation

Pteridium ferns are best propagated via division. This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost, and pots (only necessary if you will be saving divided plants for transporting elsewhere). 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 performance. To propagate your Bracken Fern by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing fern. Start from the outside and work your way in to avoid damaging the rhizome roots. Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your fern into segments, ensuring that each one has at least one thick root section.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost 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 around the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it grow.

Problems and Pests

Certain species of Pteridium are considered invasive in some regions, including Britain, Ireland, New Zealand, South Africa, and North America. Check with local authorities before planting. Pteridium ferns are generally resilient plants, but can have issues from time to time with the following pests and diseases in the landscape: