Ferns represent one of the oldest plant groups on Earth, predating flowering plants by millions of years. Unlike most common garden and houseplants that reproduce using seeds, ferns are non-flowering plants that rely on tiny spores or vegetative methods. The practice of “rooting” ferns bypasses the complex spore life cycle and instead focuses on asexual reproduction, which produces genetic clones of the parent plant. This approach utilizes existing root structures or specialized offshoots to create new plants.
Propagation by Division
Division is the most dependable and commonly used method for propagating mature, clumping fern varieties, such as Boston ferns (Nephrolepis exaltata) or Maidenhair ferns (Adiantum species). Timing is typically in the spring or early summer, just as the plant enters its active growth cycle, or when the container becomes densely filled with roots. Water the parent fern thoroughly a day or two prior to ensure the root mass is hydrated and flexible.
To begin, gently remove the fern from its container and lightly shake away excess soil to expose the root system. Identify the natural divisions or crowns where the fronds emerge from the central root mass. For ferns with thick, clumping root systems, use a clean, sharp knife or a sterilized spade to cut the root ball into sections. Ferns with spreading, rhizomatous roots, such as Polypodium species, can often be pulled apart by hand.
Each resulting division must contain a healthy portion of the root system and at least one growing point, or crown, with a few attached fronds. Discard any old, dead, or non-viable sections from the center of the original plant before replanting the new ferns. Immediate repotting into fresh soil allows the compromised root system to begin recovery and establish itself quickly.
Propagation from Runners and Plantlets
Certain fern species offer methods of propagation that do not require splitting the main body of the plant, relying instead on specialized auxiliary growth structures. Some ferns, like the popular Boston fern, produce long, slender stems called runners or stolons that creep along the soil surface. These runners naturally develop small new plantlets, or offsets, at their tips.
The easiest way to propagate from runners is to pin the plantlet end onto the surface of a pot filled with fresh potting mix while it is still attached to the parent plant. Once the new plantlet has established roots and produced a few small fronds, the runner connecting it to the original fern can be severed. Alternatively, the new offset can be cut from the parent plant and planted immediately; it will rapidly form roots when placed in contact with moist soil.
Other species, such as the Mother Fern (Asplenium bulbiferum), produce tiny, fully formed plantlets directly on their fronds. For this method, wait until these miniature ferns have developed three or four small fronds and visible roots before gently removing them from the parent frond. These rooted plantlets can then be potted up individually, ensuring the crown remains above the soil line.
Essential Soil and Environmental Conditions
Successful establishment of newly rooted fern sections relies on providing a post-propagation environment that mimics their native woodland floor habitat. The ideal rooting medium must offer both excellent drainage and superior moisture retention to prevent roots from rotting while remaining consistently damp. A high-quality potting mix should be light and airy, often achieved by combining organic matter like peat moss or coir with perlite or coarse sand to improve aeration.
Ferns thrive in a slightly acidic to neutral soil pH, typically ranging between 5.5 and 6.5, and require the potting medium to be rich in humus. After transplanting, newly divided ferns and separated plantlets demand very high humidity to prevent their fronds from drying out before the roots can fully function. Placing the new pots on a humidity tray—a saucer filled with gravel and water—or misting the foliage daily helps achieve the necessary moist air circulation.
The location for the newly rooted ferns should receive bright, indirect light, such as a spot near a north-facing window or a shaded area outdoors. Direct afternoon sunlight must be avoided, as intense rays can quickly scorch the tender fronds. Maintaining a consistent temperature, ideally between 60 and 70 degrees Fahrenheit, provides the warmth necessary to encourage rapid root regeneration and new growth.