We are deep into mid-summer with uncharacteristically cool temperatures and last week we had the first real rain of the season. When I look out my window or meander around the house I am immersed in the luscious deep green mantle created from the boughs of deciduous trees that surround my house. I am perennially in love with green. Green was the siren that called me home from the desert. Apparently I cannot live without a rainbow of greens for which there are few words to describe: emerald, lime, pine chartreuse – I run out of descriptive words almost immediately.
Although my flower garden is a giant bouquet swarming with bees, butterflies, and hummingbirds, my attention is drawn again and again to green…Looking down towards the brook I can barely see her serpentine waters, not just because the brook is starving for more rain, but because so many ferns obscure its edges. With Climate Changes so visible during this year of temperature extremes I find myself giving thanks again and again for the woodland ferns that nor only surround the house, shade my frog pond, etch the contours of the open spaces, but stretch their rhizomes down the hill hiding young cedars from too much sun, while helping to protect the moss growing along my pine strewn paths. Even the lupine field now sweetened with milkweed has its share of ferns. Diversity certainly thrives here.
Ferns are ancient plants whose ancestors first appeared on Earth over millions of years ago. Members of a division of primitive plants called Pteridophytes, ferns are one of the earth’s oldest plant groups and dominated the land before the rise of flowering plants. During the age of the dinosaurs, ferns and other primitive plants such as club mosses and horsetails reached magnificent proportions, many over one hundred feet tall. This period of the Earth’s history had a global climate of warm temperatures and high humidity, ideal conditions for ferns to flourish.
Ferns are dependent on moisture for their sexual reproduction. This method of propagation evolved before flowering plants and involves two distinct phases in their life cycle: the mature fern that we all know and recognize; and the reproductive phase when ferns are just small flat plants that look like leafy liverworts. Sometime during the growing season, a mature fern releases spores, which are the plant’s sexually reproductive cells. With adequate moisture and light, these spores begin to grow into those liverwort -like plants (prothallia) the second phase in the life cycle. If fertilization occurs, the egg cell grows into a young fern (sporophyte), and the life cycle of a new fern begins again, often taking several years to reach maturity. Fern spores germinate in moss, rotting logs, or damp exposed soil in shady locations. Moist, porous limestone rock ledges are also ideal fern habitat.
Ferns have the ability to make the most of incoming light. The fronds are divided into numerous pairs providing a large exposed surface area that allows for maximum light absorption, a definite advantage in shaded forest areas, like those around my house.
Many fern species grow in oxygen poor, water soaked environments, like the one near my well. In some of these places the upper roots lie on or above the surface allowing oxygen exchange with the atmosphere. Standing water is oxygen depleted. I used to have a wet area around my well but now with a lower water table this spot only floods after rain. Adequate oxygen improves the chances for fern reproduction and this spot is covered with four kinds of ferns!
Although the ferns on this property (with the exception of the painted fern) arrived naturally ferns make excellent landscape and garden plants, especially in shady or moist environments. So I wonder why more people don’t make use of them. Their beautiful foliage is striking, beginning when their first leaves unfurl in the spring. Later ferns develop intricate foliage in a variety of greens. The fern season extends into fall when the fronds turn yellow, gold and brown. Although ferns are not pollinated by insects, their foliage still provides food for many butterflies and moths during their caterpillar stage. Despite the delicate look of ferns, many of them are very hardy, thriving in deep shade, damp soggy soil and even dry and acidic locations in full sun! Ferns even look great as potted plants.
Ferns of all kinds help to keep moisture in the soil wherever they thrive protecting the ground from a fierce summer sun and stifling heat. When I researched Maine ferns I discovered that I had many of them on this one piece of property. The sensitive fern, maidenhair fern, lady fern, cinnamon fern, royal fern, christmas fern, polypody, ostrich fern, wood fern, and last but not least, bracken, are all ferns that live here on this small (less than 20 acre) oasis somewhere. Some like the hay-scented fern dominate my hills and woodland edges. The maidenhair fern hugs my granite rock garden spreading her delicate fronds over the mayapples during the summer. Cinnamon and sensitive ferns thrive in my wet field. Royal ferns are few, and they prefer the deep shade of my woodland paths. Lady ferns surround my vernal pool and ostrich ferns grace trillium rock. One favorite is the christmas fern because it stays a rich dark green late into the fall even after the first snowfall. The small polypody is another favored fern that thrives around a few tree trunks. (In other woodlands I often see whole rocks covered with these little ferns).
Every year a few tall bracken ferns sprout up in the middle of the woodland paths that get some sun. Because these ferns often house ticks I developed a habit a number of years ago of pulling them up by their roots, although periodically they reappear and need to be removed again. Bracken are found on all continents except Antarctica and in all environments except deserts. This genus has the widest distribution of any fern in the world. It is one of the oldest ferns with a wide creeping rootstock that may travel a yard or more underground. In some areas it forms dense thickets on hills; this fern needs good drainage. Bracken produces allelopathic chemicals (plant toxins) that can dominate other vegetation, especially after forest fires. We now know that bracken also contains a carcinogenic compound that damages DNA and can lead to cancer of the digestive tract in places where the fiddleheads are eaten. The Guardian warns that heavily infested bracken hillsides may contaminate the groundwater, a caveat for anyone who has whole hillsides of dense bracken, as many places in Britain do. Bracken thrives in disturbed soils so clear cutting in this country may encourage thick growth. After reading this information I am glad that I have been pulling up the bracken although I have mixed feelings about doing so because this fern also provides shade and moisture for desiccated mosses and some clumps of wintergreen.
When I look around this property I suspect that the diversity of plants and trees creates and maintains a balance that is often missing when we cultivate an area too heavily. This is just one more reason to encourage the growth of wild ferns.