Their architectural fronds, tropical appearance and mysterious nature can make ferns seem like the beautiful preserve of only the most skilled gardener. However, ferns can be surprisingly easy to care for – and propagate – with an ideal spot in most gardens.
Botanically, ferns belong to the group pteridophyta. Sometimes referred to as the lower vascular plants, they have a simple biological structure, but they do have separate organs and a vascular system – unlike mosses and other so-called lower plants. Ferns do not flower; instead they spread by spores as opposed to seed – distinguishing them, along with their fellow pteridophytes, from the majority of plants.
Typically, the word fern conjures an image of the deeply-cut fronds of woodland ferns such as Dryopteris felix-mas, but ferns are incredibly diverse. There’s the fishtail fern, with its holly-like fronds, or the petite parsley fern, whose leaves do resemble those of the much loved herb. Some, such as the Selaginella fern, will even trail. More commonly grown are the Asplenium or hart’s tongue ferns, a name owing to their tongue-shaped fronds. A shaded moist position is perfect for Asplenium along with many ferns; they fill a niche which not many plants can.
It can be relatively easy to propagate ferns from their spores, though patience is a necessity. The spores, located on the underside of fronds, are ready to collect as they turn brown, usually in late summer, though some of the evergreen ferns will already have ripe spores. It is easiest to slice off the frond bearing these ripe spores and leave it inside a paper bag somewhere warm for the spores to shed.
These spores can then be sown in sterile compost; it is crucial the compost is sterile as ferns will be out-competed by their prehistoric moss and lichen counterparts in a pot. Sterilising compost can be as simple as straining hot water through a muslin or paper towel and allowing it to drip through a pot; or compost can be baked in the oven at 80 degrees – if your family are used to the great lengths you will go to in the name of gardening! Either way, this will kill off weed seeds and spores.
Having prepared your compost and allowed it to cool (and explained to friends and family that it’s not a chocolate cake fresh out the oven) the spores can be sown thinly on the surface. Cover the pot with cling film and keep moist, perhaps with a mister, and place somewhere warm, such as a greenhouse or propagator out of direct sunlight.
After a period of 6 to 12 weeks, a moss-like coating will appear, known as prothallus. This is a stage between the spore and the growth of a new plant; since ferns are not pollinated it is at this stage where male and female cells can fuse to produce the new ferns. To speed this process up, carefully pot up small clumps of the prothallus and frequently spray or mist with water, allowing fertilisation to take place. Ensuring the prothallus is kept in the greenhouse or propagator, the first tender new fronds should emerge after a couple of weeks.
It may seem a little laborious, but as with any slightly unusual plant, there is a thrill of producing your own and you will soon find yourself growing rather frond of them!
- Manea School of Gardening (RHS Approved Centre)
The propagation of ferns is one of the interesting topics on the RHS courses we run.
Bookings now being taken for RHS courses commencing September.
Plant sales Saturdays 10am to 4pm, including all the plants named above.