Ferns

Back in 1853, Henry David Thoreau extolled “the ferns of various species and in various stages, some now in their most perfect and beautiful condition, completely unfolded, tender and delicate, but perfect in all their details, far more than any lace work — the most elaborate leaf we have.”

He knew whereof he wrote.

Ferns are ancient; they existed long before the more sophisticated annuals, perennials, grasses, bushes, shrubs and trees appeared on earth.

Ferns grow from rootstocks (or, more properly, rhizomes). Usually covered with scales or hairs, rhizomes are perennial (although Annogramma leptophylla, a little fern discovered about 100 years ago in the Channel Islands, is an annual).

The stalk (preferred to the word “stem,” which is usually used for flowering plants) supports the leaf and is often flat or concave in front, rounded in back, and covered with hairs or scales, especially when young.

Fern leaves are also called fronds or blades. The shapes vary widely, and their character differentiates the species. Some ferns have two kinds of leaves: Sterile leaves only support photosynthesis, while fertile leaves bear the spores (and often do both).

The word fiddlehead refers to the young, unfurling leaves of the true ferns. In spring, the new leaves are tightly coiled, resembling the head of a violin or the crook of a bishop’s crosier. Many fiddleheads are covered with dense, woolly scales for added protection against late spring freezes.

Most ferns prefer well-drained soil containing plenty of organic matter. That’s why so many can live in the woods, underneath the canopy of tall trees but delighting in the rich soil provided by eons of falling leaves. If you’re gardening in heavy clay soil, mix a 2-inch layer of composted pine bark or other organic material into the top 10 inches of dirt before planting, to improve drainage. Bird gravel or poultry grit (crushed granite) also works well for this and has the additional advantage of adding some mineral content to the organic material. Sandy soils usually drain too quickly for ferns, so always work in at least a 2-inch layer of organic material, which helps the sand retain moisture. Finally, if you’re making a fern bed, don’t do it one hole at a time, but prepare the entire area. This prevents water from filling the holes and rotting the rhizomes. If standing water is a problem, ferns also do beautifully in raised beds, which provide great drainage.

Except for a few species, most ferns need good, moist soil in partial shade. Always plan on watering if the rains forget to do their job. Most of the ferns that are happy in Asheville gardens prefer acidic soils with a pH that ranges from 4 to 7. The maidenhairs and the spleenworts prefer a more alkaline soil (with a pH of 7 to 8). You can mix in horticultural limestone or crushed oyster shells to make the soil sweeter.

[Peter Loewer, aka The Wild Gardener, is a regular contributor to Xpress.]