Nature Obscura. Kelly Brenner
are scant studies conducted on roof moss. Some sources, notably roofing companies, say moss is damaging. Others, like those of the green roof industry, state that moss can be beneficial, protecting shingles from sun damage. But the information on both sides is largely anecdotal. Since there was no consensus, I turned to the person whose name is synonymous with moss: botanist and professor Robin Wall Kimmerer. In her book Gathering Moss, Kimmerer writes that while mosses do produce tiny rhizoids, which are the moss equivalent of roots, she strongly doubts they “could pose a serious threat to a well-built roof.”
And yet, in a city where everything is meticulously maintained and managed, moss defies our modern, neat and tidy landscapes. A mossy roof is a mark of age. We accept moss in the forest or on an ancient stone wall in the country without question, but in the city, we’ve decided it’s unseemly and must be scraped away.
When we moved into our house, I was happy when the moss began spreading under our maple tree. It was pretty, softer to sit on, and didn’t require any maintenance. I considered it a win-win. I’m not alone in thinking a blanket of moss is preferable to the dramatically higher maintenance grass. In recent years the idea of a moss lawn has grown on gardening websites and in books, and now you can buy moss in sheets or as a blended moss and yogurt milkshake to spread out and grow in your garden. But it’s not a new idea; gardeners have used moss as a deliberate design element for almost seven hundred years.
Not far from Seattle is a place that has become famous for its moss garden, and one day I traveled across Puget Sound on the ferry Wenatchee to Bainbridge Island, where the Bloedel Reserve is located. During the passage I stood on the front deck, braced against the cold winter air as I looked for orcas and birds. A few gulls flew overhead along with the ferry, as though escorting it across the Salish Sea.
By the time I’d driven to the Bloedel Reserve, on the opposite end of Bainbridge Island, I had just about warmed up. For more than thirty years the 150-acre reserve was the private landscape of Virginia and Prentice Bloedel. Mr. Bloedel had a complicated relationship with the land; he was heir to his family’s timber business but he was also an environmentalist. Under his leadership, the company was the first to plant seedlings after harvesting the trees. Following his retirement, his connection to the land played out in the Bloedel Reserve, where he frequently walked and worked with landscape architects to form the grounds. Today the reserve contains formal gardens, woodland trails, meadows, and the award-winning Garden Sequence containing four “rooms,” including the Moss Garden.
The Bloedel Reserve’s Moss Garden is legendary not only locally but widely among landscape architects. It’s a place I’d learned about while earning my degree in landscape architecture. I was to meet the garden’s current caretaker, Darren Strenge, and its previous caretaker, Bob Braid—who had tended the Moss Garden since 1985 before handing the reins to Darren and turning to manage the nearby Japanese Garden.
Together, Darren and Bob led me into the Moss Garden, telling me it had been completed in 1982 and was inspired partly by Japanese gardens and partly by the rainforests of the Olympic Peninsula. At two acres, it is the largest public moss garden in the United States. Designed by acclaimed Seattle landscape architect Richard Haag, the Moss Garden, or Anteroom as it is also known, is part of the Garden Sequence, a series of four rooms starting with the Garden of Planes (now a Japanese rock garden) and moving on to the Anteroom, the Reflection Garden, and the Bird Refuge.
Not only was the idea of a moss garden unique when it was designed, but entire dead logs and stumps were brought in and left to rot in place, to be claimed by moss. Initially, 275,000 plugs of Irish moss (not a moss at all, but a perennial plant) were planted until native mosses took over. And they did, until the garden became a mosaic of varying shades of green containing more than forty species of moss with almost none of the original Irish moss remaining, outcompeted by the native moss.
Throughout the garden, moss-covered mounds of vague, fuzzy shapes—remnants of the original logs—slowly collapse in on themselves as they gradually rot. Bob told me that Mr. Bloedel was fascinated by these stumps and nurse logs. Native plants such as sword fern, evergreen huckleberry, and salal grew on some of the stumps and logs while along the southern edge of the garden, the thorny devil’s club marked the border. Old western red cedars towered over the garden, creating a shifting pattern of light on the ground where the sun filtered through. Moss crept up the flare of the tree trunks, making it hard to distinguish where the ground ended and a tree began.
The more I looked, the more I could begin to detect patterns in the ground. It was not a simple blanket of green, but a complex tapestry of many tones, some tending toward blue, others tipping to yellow. In between the greens stood patches of rust from the reddish capsules of common smoothcap moss. But the pattern isn’t random, and to know the mosses is to understand the various microclimates they favor. Some species are tolerant of the sun and boldly grow where no other mosses dare to creep. Others crowd around the soggier parts of the landscape, wanting to keep their toes constantly wet. Some live high, hanging on the branches of trees and never touching the ground. A few grow side by side, competing in a slow-motion struggle to gain more ground.
As we walked through the moss garden, Darren occasionally hopped off the path to pluck out various species, and I could easily feel his connection to the outdoors. He’s been working at the reserve since 1997 when he decided, after finishing his master’s in botany and working in a lab studying pollen fertility, that he’d rather spend his days outdoors than in a laboratory. He has been getting to know the reserve ever since, and the Moss Garden in particular, after he took over its care in 2017. At one point on our tour, he leaned down over a bed of green, teased out a single tiny plant, and handed it to me. He said it’s called Menzies’ tree moss, and I could easily see why. The foliage of the “tree” sat atop a long, brown stem, reminiscent of a trunk. The slender leaves radiated down along arching “branches,” and as a whole it looked like a miniature tropical tree. However, unlike a tree, the plant had two thin stalks protruding from the top. These setae, part of the moss’s reproducing sporophyte, were red at the base, with the color shifting in gradients to green at the top, where two bright green, oval-shaped capsules sat, nodding downward, nearly ready to release their spores.
Next Darren handed me snake moss, which he said he liked showing to visiting kids. One after another, he pulled up tiny, individual plants of different mosses, and as they started to accumulate on my notebook, I could see how different they were one from the other when removed from their mats. One stood at least four inches tall with dark green, swordlike leaves. Another sprawled seaweed-like in a tangle of bright green, and still another looked like a feather taken from a parrot. They were all green, but the textures and variations of green were astonishing.
To describe the garden as a carpet would be a disservice because it looked much softer than any human-made carpet. The temptation to feel that soft, damp green on my feet was irresistible, and I joked to Darren that I would love to take my shoes and socks off and walk through it. He replied that he actually does that sometimes, when no one is around. I don’t think he was joking.
Once Darren and Bob left me to return to their duties, I retraced my steps back to the beginning of the Moss Garden, where two moss-covered rocks stood as guardians, to walk through the garden again, alone, in the quiet of the reserve. But what I didn’t realize was that I was starting my walk out of order, in the second room of the Garden Sequence. I had missed the first room.
Richard Haag, who designed the Garden Sequence at the Bloedel Reserve, had long been attached to the Pacific Northwest, spending most of his professional life in Seattle. He designed landscapes in the region but also around the world, as well as founding the landscape architecture program at the University of Washington, before he was chosen to shape these acres of formerly logged land.
The Garden Sequence begins in what was once the Garden of Planes, adjacent to the Moss Garden, but the start of the sequence no longer exists, as I would find out at the end of my walk when I visited the first room last. Originally the Moss Garden was a bog overgrown with pink-flowered salmonberries, and the tiny rivulets of water forking through the moss are evidence today of that bog. Haag said this garden was “created by selective subtractions of the nuances of nature from the chaos of a tangled bog,” reflecting a trademark of his design style. Here, as in another