Ferns: A Circle of Fronds

Ferns: A Circle of Fronds

October 19, 2001
Photo by: Betsy Arvelo

Considering that ferns have been around for 400 million years, the most mysterious thing about them is why they remain so mysterious to many gardeners. Lacking flowers, seeds, and fruit, ferns are unjustly underappreciated, except as a backdrop in a vase of cut roses or as a hanging porch plant. Ferns are subtle, but subtlety has its own intrigue. We first notice them in the spring, when the coiled forms of the new growth, called croziers, or fiddleheads, emerge and quietly unfold into fronds. Turn the fronds over in summer, and the fertile ones will be dotted with clusters of spore cases, or sori. As the sori mature, millions of spores are released — flung away from the frond, as if by a catapult. Only 10 percent of all fern species are found outside of the tropics, but among them are those that will live happily in nearly every site. Most ferns, including the lady fern, Athyrium filix-femina, prefer rich, humus-laden, well-drained soil, dappled shade, and a consistent supply of moisture. 

WORKING WITH THE CYCLE To propagate, collect the spores from mature sori; store spores in glassine envelopes until you are ready to sow. You can easily divide existing plants by cutting the branches of the rhizome and replanting.

SPORES Ferns do not have flowers or seeds; they instead reproduce sexually by spores. The undersides of fertile fronds are decorated with patterns of sori, clusters of up to 100 spore cases that each enclose 64 spores. When ripe, the cases open, releasing millions of tiny spores.

CROZIER It is the graceful unfurling of the fiddleheads in spring that first calls our attention to ferns. Unlike the leaves of most plants, which grow in all directions, the fern frond matures from the base up — the crozier’s tight spiral uncoils into the leaf’s characteristic blade shape.

RHIZOME Neither nature nor the gardener has to depend solely on spores for reproduction. In most fern species, vegetative propagation occurs through the branching of the plant’s underground portion, or rhizome. On the lower side of the creeping rhizome are slender roots that provide stability and take in nourishment for the plant. New fronds are produced at the branch tips.