How to Propagate Fernbrake (Bracken Fern)? Detailed Guide to Fernbrake Propagation Techniques

Fernbrake, also known as fiddlehead, cat's claw, and dragon-head vegetable, contains 18 kinds of amino acids and more. Modern research suggests that the cellulose in fernbrake can promote intestinal peristalsis and reduce the absorption of fat by the stomach and intestines. Fernbrake is sweet in taste and cool in nature; as a medicine it has effects such as detoxifying, clearing heat, moistening the intestines, and resolving phlegm. Regular consumption can lower blood pressure and relieve dizziness and insomnia. Fernbrake can also stop diarrhea and promote urination; the dietary fiber it contains can promote gastrointestinal peristalsis, has the effect of descending qi and relieving constipation, and cleansing the intestines and expelling toxins, and can also treat diseases such as rheumatoid arthritis, dysentery, and coughing up blood. It also has a preventive effect on measles and influenza.

Fernbrake propagation includes sexual reproduction, asexual reproduction, and tissue culture, among other methods.

Sexual reproduction

Collecting spores: choose sori that are brown in appearance and whose sporangia have not yet split open. Use clean scissors to cut off the spore-bearing leaves, place them in a paper bag, and air-dry them for later use.

Making the culture substrate: sowing spores in mixed soil is both economical and convenient. Mix peat soil, river sand, and turf ash in proportion, stir well, and sift to make mixed soil, then steam-sterilize it for half an hour.

Sowing spores: one day before sowing, place the prepared mixed-soil culture container in shallow water to fully moisten it, evenly scatter the spores on the culture substrate, then cover it well, soak it in shallow water, and take it out the next day for cultivation.

Spore cultivation: move the sown container to a hotbed or incubator for cultivation, maintaining the temperature at 25°C, humidity above 80%, and light for more than 4 hours per day. After 1 month the spores germinate and grow into tiny protonema, then develop into flat heart-shaped or ribbon-like gametophytes. Archegonia and spherical antheridia grow on the underside of the gametophyte. At this time, spray twice a day for 1 consecutive week; the sperm swim out through water and combine with the egg to form an embryo. After one week it develops into a small sporophyte plant.

Transplanting the sporophyte: after the sporophyte grows 3 to 4 leaves, carry out the first transplant, still preferably using mixed soil as the bed soil. After 1 to 2 weeks, move it outside the hotbed; after the seedlings grow larger, carry out the second transplant or field planting.

Asexual propagation techniques

Asexual spore propagation: some ferns grow bulbils in the axils of the pinnae and below the top of the leaf rachis; some have apical meristems of the rachis that touch the ground and produce new plants, or vegetative leaves whose tips touch the ground can also produce new plants.

Vegetative propagation: segment the creeping stems and cultivate them in sections, or cut the upright rhizome lengthwise into 2 parts for cultivation, but each section must have roots and leaves to survive easily.

Tissue culture: the somatic cells of ferns also have regenerative capacity. Using this method, only a small portion of vegetative organs needs to be collected to culture a large number of fern seedlings.

For sexual reproduction, in early to mid-June, when the sporophylls have expanded and the edges are slightly yellow, cut the leaves back, place them indoors on plastic sheeting or paper to dry naturally; the sporangia split open and the spores scatter out. Collect the spores and store them in a refrigerator.

Sift crushed peat or humus soil, disinfect it with carbendazim, then make a bed 1 m wide and 10 cm high, water it thoroughly, and then evenly sow the spores on the bed surface. Cover the bed surface well with plastic film. Water frequently afterward to maintain humidity, and after about 2 to 3 months small embryo stems will grow.

Rhizome propagation: choose a plot with ample sunlight and loose, fertile, moist, well-drained soil as the transplant site.

From late April to early May, dig up wild rhizomes, choose rhizomes that are purplish-red and bear more buds and fibrous roots, and cut them into rhizome sections 30 to 40 cm long; especially choose rhizomes that also have mixed buds, as they survive easily and give high yields.

After digging up the rhizomes, it is best to plant them promptly to increase the survival rate. If they cannot be planted immediately after digging, they need to be placed in a moist place or covered with wet straw curtains. The planting row and plant spacing is 40 cm × 40 cm, and the planting depth is 10 cm. Seedlings from sexual reproduction can be planted in trenches in the same way in autumn or spring.

How fernbrake uses spores for propagation

(1) Spore treatment: take collected mature fernbrake spores and in February treat them with 300 mg/L (ppm) gibberellin for 15 minutes, which can promote spore germination.

(2) Sowing spores: pour the treated spores into a watering can filled with water, shake well, and spray them into a wooden box containing humus soil or peat soil. After sowing, cover the wooden box well with paper or film and place it under a temperature condition of about 25°C. It takes about one month for the spores to begin germinating.

(3) Cultivating young plants: when the young ferns grow to 6 cm high, move the young ferns from the seedling tray into a hotbed at a spacing of 4 cm × 4 cm for cultivation. In late May, plant them out in the field.