In primeval moss, a gamut of greens
Recently I cradled a brown, wizened and lifeless stem of a plant in my hand and waited for Linda Davis.
She arrived bearing a water dropper and some words of advice: Have your magnifying glass ready “or you may miss it.”
Once soaked, and within a few seconds, the tiny whorls of brown fur turned green and unfurled like a fern greeting the spring, only in a flash and in miniature. This miracle plant was merely a common moss named atrichum. Mosses are one of Earth’s primeval plants, and to see this scant example dance back from the dead was strangely affecting, as if I were holding a 450-million-year-old life force in my hand – which I was.
Perhaps this is why moss gardens can be so sublimely meditative, something Japanese gardeners figured out a long time ago. Moss gardens here are rarer, and it takes effort and care to keep them looking good. Looking good for us, that is. Mosses don’t care to be ornamental (though they are). They just want to find their niche and grow and reproduce. This is why you find some in the cracks in the city sidewalk, on decaying logs in woodlands, on stone walls and amid failing lawns. It is this last aspect that has given them an unfair reputation as undesirable invaders. Maybe it’s the lawn that needs to go. But to value mosses in the landscape, it is essential to greet them at their level, through the lens of a botanist.
This is why I joined more than half a dozen other curious souls late last month for a moss workshop given by Davis and her husband, Charlie Davis, naturalists with the Natural History Society of Maryland, at Benjamin Banneker Historical Park and Museum in Catonsville. Charlie stayed indoors with seasoned moss devotees, seeking to identify species with dissecting tools and microscopes. Linda took five of us moss newbies outdoors, around an old house that functions as a meeting place, proving that you don’t have to go deep into the woods to find several species of moss. You need only find a leaking gutter or a dripping faucet.
On the porch, she told us that mosses are not like other plants; they have no interior plumbing that connects the leaves to the roots, and as nonvascular plants they share (and dominate) a plant niche called the bryophytes. The
others are the hornworts and liverworts, not to be confused with Hogwarts and liverwurst.
“These guys are not sucking water,” she told us, “and yet their whole life history depends on water.”
Without xylem and phloem and with paper-thin leaves, mosses rely on direct contact with water to stay hydrated and nourished and to reproduce; male and female parts are separate, and the sperm – not pollen – needs water to swim to its target. The moss then produces a capsule-bearing stalk – a sporophyte – and the capsule contains spores, not seeds, which are so light and tiny that they can find their way to the jet stream and migrate around the globe. There are no roots, but they have anchoring structures called rhizoids, which can reach down a few inches. The leaves contain a natural antifreeze agent, and mosses are among the few ground-hugging plants that stay green through the winter. They have compounds that make them unpalatable to pests and diseases, and thus stay clean and uneaten. They trap water and pollutants, they control erosion, they grow where other plants fear to tread. Who could call such a plant a weed?
After taking the monthly class, I couldn’t walk anywhere without seeing mosses and noticing the differences in size, habit, colors and sporophytes between species.
Mosses are all around us, but what of their considered use in the garden? I have a few thoughts: Start small and find ground that undulates; moss is so low-growing that it can look less interesting on a flat area. As with any other garden plant, context is everything, and your moss patch should be framed in some fashion and planted with other sympathetic flora for textural contrast. But it must be in scale; asarums, foamflowers, snowdrops, ferns, mondo grass, creeping phlox, sedges and even dwarf azaleas would make good partners.
Surprisingly, perhaps, moss gardens are not without maintenance needs. (No worthy gardens are.) Patches must be kept free of leaf litter and other debris and must be weeded. One imagines a Buddhist monk on his hands and knees with a hand brush and tweezers, which, come to think of it, would beat a lot of other domestic chores.
I asked moss expert Annie Martin what would be the watering regimen if moss were to remain green and handsome in a non-monsoon year. Three times a day, she said, but for no more than three minutes a spraying. “If you can only do it once, choose late afternoon,” she said. Even that seems onerous, but as she said, “it’s way less water than people use for lawns.”
We think of mosses growing in shade gardens on acidic soil – some mosses take deep shade and are perfect for areas where little else wants to grow – but some species will grow in full sun and others on limey soil. The key is to find the right one.