Division is a reliable method for propagating new ferns and rejuvenating older, crowded plants. Success hinges entirely on the plant’s underground structure, specifically whether it grows from a central crown or a network of rhizomes. This process provides the plant with fresh soil and space, encouraging vigorous growth.
Identifying Ferns Suitable for Division
The ability to successfully divide a fern depends on its natural growth pattern. Ferns that form a distinct, tight clump or central crown are the best candidates for this technique. Clumping varieties, such as Boston ferns or Maidenhair ferns, grow from a concentrated root ball and are easily separated into smaller sections using a sharp tool. Dividing these plants every three to five years prevents them from becoming root-bound and promotes health.
Other ferns have a running or spreading growth habit, utilizing thin, creeping rhizomes or stolons to colonize a larger area. While these can be propagated, the method involves separating the rooted runners rather than cutting a solid, dense root mass. Forcefully cutting the thin, spreading network of a running fern is generally less effective than simply separating naturally rooted sections.
Step-by-Step Guide to Dividing Ferns
The optimal time to divide most ferns is during their active growing season, typically in early spring as new growth or fiddleheads emerge. This timing allows the newly separated plants the entire season to establish a healthy root system before winter dormancy. Before beginning, all cutting tools, such as a sharp knife or spade, should be sterilized to prevent the transmission of plant diseases.
The next step involves gently removing the fern from its container or digging it up from the garden bed, taking care to minimize damage to the root ball. For large, dense clumps, you may need to slice through the entangled roots to extract the plant. Once the root ball is exposed, locate the natural division points or growth crowns, which often appear as individual bundles of fronds.
To make the cut, use the sterilized, sharp tool to slice cleanly through the root mass or thick, fleshy crown. It is important that each new section retains a sufficient mass of healthy, fibrous roots and at least one viable growth point or frond. Fern root balls can be surprisingly tough, requiring a swift, decisive cut to minimize tearing and trauma to the plant tissue.
The new divisions should be replanted immediately into fresh, well-draining soil at the same depth they were previously growing. Using a new potting mix or amending the garden soil with organic matter helps provide the necessary nutrients and aeration for the recovering roots. Discarding any dead or mushy center portions of the original clump is also beneficial for the long-term health of the new plants.
Ensuring Successful Replanting
Immediately after replanting, water the newly divided ferns thoroughly to settle the soil and eliminate air pockets. Consistent moisture is necessary, but the soil should never be allowed to become waterlogged, which can lead to root rot. Maintaining this balance is important because the root system’s ability to absorb water is temporarily diminished.
The fresh divisions should be placed in an environment that provides bright, indirect light and high humidity. Direct sunlight can easily scorch the delicate fronds of a stressed plant, hindering its recovery. Maintaining humidity levels consistently above 60% is particularly beneficial, often requiring the use of a humidity tray or a room humidifier.
A newly divided fern may show signs of transplant shock, such as drooping or temporary wilting, as it adjusts. Providing a stable environment and avoiding extreme temperature fluctuations helps the fern recover from this stress. Successful establishment is indicated by the emergence of new, tightly coiled fiddleheads, showing the plant is growing actively again.