I always look forward to visiting the Heronswood Northwest Research Nursery. When I was there last, in fall, the days were far shorter and cooler than they are now in late June. I usually take the Bainbridge Island ferry from Seattle and ride on the open deck; the city recedes and the dark green hills of the island advance.

The more I come here, the more I see the garden as a snapshot in time. It is a mature garden, with some 7000 unique entries that come into their own throughout the year. The flush of under-story plants now is largely different from what I saw in spring and fall. There are lots of anemones, geraniums, primulas, and various poppies; the singularly lovely spotted orchid (Dactylorhiza foliosa); and the exotic-looking Jack-in-the-Pulpits (Arisaema franchetianum and Arisaema wilsonii) and Paris polyphylla, a native of China. Thalictrums and rodgersias are at their peak.

The rhododendrons that in spring were almost gaudy now seem dull, but the assorted dogwoods and magnolias are flourishing. In the past, I’ve scoffed at variegation (calling it just a chloroplast mutation), but I’ve developed a taste for it, particularly in the woody plants—Prunus lusitanica ‘Variegata’, various Osmanthus, and a Kerria japonica ‘Variegata’ are all virtually luminous.

Ferns seem to be the constant exception to this successional exhibit of the flowering nursery plants. Ferns are everywhere in the garden, and they look great. And they looked great in spring and fall too. There are soft green ferns that are nearly 6 feet high and small bronze-hued ones that hug the ground and have fronds not more than 7 inches long. It’s my belief that ferns are underutilized and underappreciated in gardens. Placed properly, they require minimal care and are remarkable and beautiful in and of themselves. And they are excellent foils for other plants in a garden.

The fossil record is replete with ferns from the Carboniferous Era, but most of these represent extinct species. The ancestors of our modern ferns evolved later in the Mesozoic Era beginning 250 million years ago. Flowering plants (angiosperms), in contrast, did not appear until about 140 million years ago.

Ferns, along with clubmosses and horsetails, comprise a relatively primitive group of vascular plants, rather quaintly called “cryptogams” (or hidden gametophytes). They are spore-bearing and do not produce flowers, fruit, or seed. They have a two-stage life cycle in which the spore is a simple reproductive body that germinates and develops into a new plant. In these vascular cryptogams, when the spore germinates, it produces flattened, usually green, vegetative tissue (called a “thallus”) that is so small it’s usually unseen. On the thallus, plant sex organs (one or both) develop; this is the gametophyte or the “hidden” gamete-producing plant stage. After fertilization of the egg, the characteristic plant emerges. This is called the “sporophyte”, the stage that bears the spores. Ferns are often cultured from spores, just as flowering plants are grown from seeds (but the spore is nowhere near as neat a package as the seed).

Identifying ferns is difficult. In flowering plants, identification and classification is highly dependent on flower structure. In ferns, the position and arrangement of sori (the spore-bearing structures) are taxonomically important. Sori are found on the under (dorsal) side of the fern frond. In some groups, the sori are arranged in long strips; in others, the sori are separate, unique bodies. Another feature important in classification is growth habit (erect, prostrate, and so forth); vegetative structures such as rhizomes and leaf shape and venation are also significant. Even so, the literature is filled with conflict, contradiction, and ambiguity. The current name for the lady fern, a large, attractive, easy-to-grow species hardy to USDA Zone 5, is Athyrium filix-femina; it’s had 62 names since 1753 when it was first identified.

In nature, there are between 10,000 and 15,000 fern species in about 40 families, depending on how they’re classified. Most North American and European ferns are in cultivation, but this is not so with the ferns of the Southern Hemisphere and the Himalayas. Many eastern Asian ferns are only in cultivation there, but several are in the Heronswood garden. There is autumn fern (Dryopteris erythrosora, cultivar Brilliance); widely available, it is native to Japan, Philippines, China, and Korea, has an unusual bronze color, and 30-inch fronds. It is hardy to USDA Zone 5. Another is Japanese painted fern (Athyrium niponicum), which has striking silvery or pewter shading on the frond costae and lamina. It’s native to China, Japan, Korea, and Manchuria, grows low to the ground, and has mere 15- to 20-inch fronds. It’s hardy to Zone 3.

Deer ferns tend to do well in drier soil, and several types of them are scattered throughout the garden. One is Blechnum spicant, which has upright, spiky (hence the species name) fronds standing about 30 inches tall that are glossy green. It is native to Europe and western North American and is hardy to USDA Zone 5. Blechnum penna-marina is a small deer fern native to southern South America, New Zealand, and southeastern Australia. It has the same bright green foliage as its cousin but fronds no more than 7 or 8 inches long; it would be an excellent choice for a shady rock garden. It’s also hardy to Zone 5.

Among my favorites at Heronswood is the giant chain fern (Woodwardia fimbriata), which gets its common name from the chain-like distribution of its sori. This fern is native to western North America and can be found from British Columbia to Baja California; it’s fairly common on the Kitsap Peninsula, where Heronswood is located. It has long, light green, feathery fronds. Growing in the shadows of a moist woodland, it can be 9 feet tall. The ones at Heronswood are not that tall, and in a garden, their maximum height will be about 5 feet.

When you change or add to your garden, I recommend you consider ferns. There are lots available that will answer a variety of needs. They will be stable, eye-catching components of your garden and will highlight its more transiently beautiful members.