Table Of Content

tiae ii^ the autumn Photo hi; Richie Steffen • f 7k ' * V ife Northwest Horticultural Society YVi a 'A jrw * .v Ip . y JM Words and photos by Richie Steffen Nandina domestica ‘Filamentosa’ covered in ice Winter damage to plants is a com¬ contribute to whether a plant will endure can tell you, hardiness is a fuzzy line. So, plicated issue. Last winter we saw many uninjured or end up on the compost pile what affects hardiness? One main factor plants show unexpected injury, while in the spring. is a plant’s origin. The eastern flowering other plants that we expected to suffer dogwood is an excellent example. Its substantial damage survived unscathed. The first factor to consider is the plant native range is southern Maine to north¬ Part of the problem in forecasting winter itself. Is it a hardy plant? This seems easy ern Mexico. More northerly selections damage is that a number of variables enough to answer, but, as most gardeners drop their foliage promptly in autumn GARDENnotes FALL 2017 and withstand winter tempera¬ weather can easily induce tures as low as -20°F, whereas bud break, and, occasionally, the Mexican form, Cornus these very hardy plants may florida var. urbiniana, will be severely damaged by a late fight dormancy, slowly drop¬ spring frost. ping foliage until late autumn. The latter will survive lows to The culprit in causing these -5°F but with a susceptibility injuries is ice. Ice within the to damage from early hard cell will ultimately destroy a freezes. plant s structural integrity. As the ice expands, it damages the Another factor in hardiness protoplasm within the cell and is the way in which a plant eventually the cell wall rup¬ A hardy Rhododendron with leaves tightly curled hardens off for the winter. tures, resulting in the collapse Plants from colder regions will of the cell. typically enter into dormancy sooner than plants from So, once acclimated, how milder climates. Plants have do plants tolerate cold tem¬ evolved a number of physi¬ peratures? A method typically cal features to adapt to cold employed is to concentrate climates and temperatures as sugar compounds and/or well as less obvious internal “anti-freeze” proteins within strategies. In tundra habitats, the cell wall to prevent the most plants have small leaves, formation of ice crystals. often with stems, buds, and Many plants can also super¬ foliage covered in hairs. Their cool water, allowing it to drop roots are shallow to keep them below the freezing point yet free from permafrost, and their remain a liquid. These anti¬ A less hardy rhody, leaves wilted but not rolled stature is short to minimize freeze methods alone are not wind exposure. effective if the temperatures are very severe, and they cannot be During late summer and fall, all hardy fully effective if the cooling is rapid. plants begin a process of preparing for Cell damage is often associated with cold weather. The most dramatic and rapid cooling and possibly rapid thaw¬ one of the most effective steps is to shed ing. Plants not quite hardened off and foliage. This is commonly accompanied plants using this anti-freeze method by brilliant autumn colors—much to alone can show irregular water-soaked the gardener s delight. Evergreen plants patches of ruptured cells when they will cease growth in late summer to have been damaged by cold. Later, these early autumn, and the terminal buds on patches will blacken or turn brown. both evergreen and deciduous plants Extensive damage can prevent the free will enter into a deep dormancy. Plants flow of water through the leaves and that regularly experience long periods stems, resulting in death of the plant. of below-freezing temperatures can also have a chilling requirement that Plants that have evolved in cold regions needs to be fulfilled before growth can have a much more effective method begin again in the spring. These very- of dealing with low temperatures. cold-tolerant plants rarely have any cold Once the plant is fully hardened oft damage in early to mid winter. After the for winter, the cells have the ability to chilling requirements have been ful¬ expel water from inside the cell to the filled, however, a week or two of warm The Miller Garden in winter space between the cells during freezing weather. This allows ice crystals to form LITERARY NOTES without rupturing the cell walls. The colder the weather, the more water is expelled, resulting in squashed, shriveled, and desic¬ from the Miller Library cated, but intact, cells. When we see this in our garden, the plants appear to be wilted and in fact they are wilted, just waiting for by Brian Thompson warm weather to melt the ice and rehy¬ drate the cells. A classic example of this is rhododendrons. When the temperature dips below freezing, the leaves of hardy The Rock Gardening section of the Miller Library is quite extensive. It contains rhododendrons will roll up as tight as cigars some of the library’s oldest tomes rich in detail, but the scarcity of newer titles until sufficient warmth returns. If you are might suggest this form of gardening has gone out of fashion. growing more tender rhododendrons, you’ll notice that their leaves do not roll. These However, for those interested in creating gardens that are tolerant of our tender forms likely rely on the anti-freeze droughty summers, rock gardening is an excellent style to consider. To help method, resulting in damage during our spur your interest, I recommend Rock Gardening: Reimagining a Classic Style worst winters. (2016). Very hardy plants, especially evergreens, can Author Joseph Tychonievich has an infectious, enthusiastic writing style and still be damaged if the cold is prolonged easily brings new life to an old gardening subject. His research finds rock gar¬ and we have wind, as wind will draw mois¬ dens evolving with expanding plant palettes. They are set in both sun and shade ture from the exposed foliage. As long as and can be compatible with nearby, more lushly planted areas. Moreover, they the weather is cold, the water cannot be don’t necessarily include rocks! “This book aims to be an introduction into that replaced in the leaf, and the leaf will suffer wide world of the rock garden in all its diverse modern incarnations.” under drought stress. Even if the tempera¬ ture warms, the soil can remain frozen, He uses many examples from throughout the United States and the United preventing the roots from replenishing the Kingdom and includes two gardens in Medford, Oregon. His list of recom¬ water lost through transpiration. mended plants is restrained but goes well beyond the traditional alpines, and encourages experimentation. As we move into fall, there are a few things we can do to minimize winter damage. George Schenk is best known for his classic The Complete Shade Gardener Watering in summer and early fall during (1984 and 1991), a bible for me in my early days of gardening in my shady dry periods helps keep many garden plants backyard. What I learned recently is that his writing career began much earlier, out of a drought stress. Drought-stressed with the 1964 Sunset publication How to Plan, Establish, and Maintain Rock plants often try to grow once autumn rains Gardens. begin, resulting in easily damaged tender growth. Limiting fertilizer after August 1 Early Sunset books like this are much meatier than recent ones, and the writing will aid in keeping late-season growth to here is pure Schenk, a witty combination of observation and intuitive insight, a minimum. A final preventative measure all enhanced by the photographs of Don Normark. Best of all, the author draws is to mulch in late fall. Mulching will help on his Seattle-area roots for many of his examples. keep moisture levels even in the soil during dry weather as well as provide an insulat¬ Like Tychonievich, Schenk includes some unexpected discussion topics for ing barrier to keep the roots from freezing this genre, including desert, woodland, and bog gardens. He closes with what during prolonged cold. Unfortunately, he calls the plant biographies “of the best, the strangest, and the most charming nothing will eliminate cold damage better plants for American rock gardens.” Comparing the plant lists from both books, than a mild winter, but with a little preven¬ I concluded that rock gardening is a tradition that updates very well. tative care we can reduce the ravages of the upcoming season. ^ Brian Thompson is the manager and curator of horticultural literaturefor the Elisabeth C. Miller Library. Richie Steffen is the Director/Curator oj the Elisabeth C. Miller Botanical Garden. GARDEN notes FALL 2017 DOWN ON MY KNEES In Praise of Amateur Gardeners by Daniel Mount “Professional gardeners don’t kneel,” that’s what my But it had no heart. new assistant said. He was always just a tad early for work. He was always cleanly dressed with a near-military crispness. He So I threw some heart into her garden. It’s a little more dishev¬ worked smart, had good ideas, and knew plant names. eled now. He was a professional gardener and I was lucky to have him. Every leaf is not whisked away on the jet stream of a backpack blower the minute it hits the ground. There are even clutches of On the other hand, I, by his standards, am not a professional deliberate “weeds,” and moss on the paving. It costs her a lot of gardener. I invariably show up late, sometimes in dirty clothes money to get that look, so in that sense it is a professional job. from the day before. I am clumsy and often work harder than But I take an amateur’s approach. necessary, repeatedly hurting myself. I make lots of mistakes, and am forgetting more plant names these days than I can remember. And it works. My client is now happy with her garden. I also kneel. I am not trying to deride professionalism, or professional gardeners for that matter. I kneel a lot. I’ve learned a lot about what to do, and what not to do, from the professionals. I My yoga instructor once commented that admire the disciplined approach my col¬ I had long legs and a short torso, making it leagues take, their intelligent choices, and hard for me to touch my toes. I am a natural informed decision-making processes. for squatting, and kneeling, I thought. But that is not the only reason I kneel. I like to be But I admire amateurs more. I’ve learned on the ground. I like to be right down in the so much from the impulsive plant choices dirt among the plants, my knees aching from and slap-dash designs of my friends, I kneeling. can hardly quantify it. I can even say I’ve learned to love negligence. It makes this professional as happy as any amateur. I had a roommate once who, after I diligently cleaned the kitchen, took out a The moniker “amateur” I know can a have a pejorative feel, glass, filled it with water, drank the water, then put the glass in implying a dabbler or dilettante. It almost always designates the spotless sink. someone involved in an activity with no expertise, thus no financial gain. But it comes to us from the French and means “Now it looks like someone is living here,” he said. It took a simply “lover.” while for my aggravation to abate. But I got his point. A few years ago a woman approached me about taking on her I still think cleanliness is a virtue, and timeliness a common garden, a large estate professionally designed and profession¬ courtesy. I still believe in discipline in design and maintenance. ally maintained. As we toured her garden she repeatedly said, “Nobody loves this garden.” Yet the times I feel the most grateful that I am a gardener are not when I am orchestrating a massive project, or in a frenzy of I had to agree. tidying before a client’s party, but when I am on my own ground, and on my knees. ^ Certainly everything was clipped, deadheaded, and weeded into a benign tidiness. Most of us would have said it was a fine Daniel is a former NHS board member and a frequent contributor garden, impressive in scale and design. to GardenNotes and other publications. You can read his blog at mountgardens.com. .Words and photos by Ray Larson Hawthorne bridge over daylighted Arboretum Creek looking northwest By the time you read this, the new Arboretum Loop Arboretum. The new construction totals 1.2 miles, and when Trail will be open to the public. A multiuse trail for pedestri¬ combined with Arboretum Drive E it makes a 2.5-mile loop ans and recreational bicyclists had been a goal for Washington with a spur to East Madison Street. The new trail runs roughly Park Arboretum since the 1960s. Thanks to mitigation funds parallel to Lake Washington Boulevard East, winding its way provided to the Arboretum as a result of the State Route 520 along many preexisting trails and around major trees and expansion, this project has finally come to fruition. The proj¬ landforms. Four bridges now cross the daylighted Arboretum ect was prioritized in 2011 by the Arboretum and Botanical Creek. A significant component is the opening up of areas of Garden Committee (made up of University of Washington, the Arboretum that used to be inaccessible during the wetter City of Seattle, Arboretum Foundation, and community and nine months of the year, along with restoration of the creek. state representatives), and planning began in earnest. It is the The Berger Partnership designed the trail with input from first phase of a long-term plan to connect the Arboretum to the UW Botanic Gardens staff and the City of Seattle Parks and Montlake Bridge and the University District by way of a trail. Recreation department. Construction began in April of 2016 and has been managed by the City with significant input from During the design phase, and partly due to the 2011 closure UW. Despite the wettest winter on record, progress remained of Arboretum Drive East to through traffic, it was decided steady. The first section of the trail, between E Madison Street to make the trail a loop around the central portion of the and Arboretum Drive E, opened in March. GARDENnotes FALL 2017 Due to federal standards governing grading, creek restoration to a more multiuse trails, the asphalt pathway is natural condition, and the installation 10 feet wide over most of the route; of thousands of native plants. One of 2-foot gravel shoulders line each side. my goals in the wetland areas was to Sections that should experience lighter significantly increase the diversity of use are paved at 8 feet wide. In the native species. Where the trail passes two years prior to construction, more through collection areas, such as the than 2,400 plants along the route were oak and viburnum groves and Pacific evaluated and surveyed by UW Botanic Connections Garden, new plantings Gardens staff. In several places the trail and increased diversity will be added. was moved or adjusted to save larger Much of the planting in collection or unusual trees. Fewer than 150 trees, areas will occur throughout fall and most less than 6 inches in diameter, were winter. And, of course, there will removed for construction. Trees were finally be a place for casual bicyclists moved when possible and hundreds of to meander through the Arboretum. plants were propagated. Throughout The trail was designed to keep speeds Washington Park, more than 800 trees down and traffic calm. Hills and Larch bridge over restored Arboretum Creek have been replanted, many replacing curves will make this a slower route looking southwest invasive species along the playfields at than using neighborhood streets, and the south end of the park. the trail will be monitored to make sure that speeds and use are appropriate for all visitors. Several major benefits were planned as integral to the project. The Arboretum will feel much bigger to visitors, as more of the Plan a visit to the Arboretum soon. We hope you’ll enjoy the 230 acres will be easily accessible year-round. Formerly, much new trail, the new views along the restored creek, and the new of the portion between Lake Washington Blvd E and Azalea plantings along the route. ^ Way was simply too wet to walk between October and June. In these sections, the new trail is on a raised “leaky” berm that Ray Larson is Curator of Living Collections and the Otis will keep feet and wheels dry while letting water pass under¬ Douglas Hyde Herbarium at the University of Washington neath through regularly spaced culverts. The historic wetland Botanic Gardens and a former NHS president. function of much of this area has been restored—with better ^t§ Northwest Horticultural Society Discovering Hugelkultur Harvest House Food Forest Words and photos by Justin Henderson Located in Graham, Washington, not soak up water resources, require soil strong biodiversity of plants. However, it Harvest House is a food bank whose amendments, or create burdensome work wasn’t until we happened upon the prac¬ goal is to help the community deal with for our volunteers. With this in mind, we tice of hugelkultur that we discovered the food insecurity. Harvest House s one- researched every possible method of how ultimate answer. acre Food Forest was begun with the to reduce our impact on the environment, purpose of creating a sustainable garden and we determined the amount of human Hugelkultur (HOO-gul-culture), or “hill that would provide free access to fruits energy that would go into sustaining culture,” is an ancient Eastern European and vegetables. While pursuing the goal the garden. This led us to the methods method of planting. If done properly, it of providing food for those in need, we we currently practice: mulching heav¬ not only significantly reduces the need wanted to ensure that the food forest did ily, eliminating tilling, and developing a for irrigation, it also lessens the need for Food Forest shelter surrounded by hugelkultur mounds I’m n * GARDENnotes fall2oiz Harvest House Food Forest requires minimal human effort, yet still generates an abundance of fruits and vegetables. fertilization. A good hugelkultur raised After extensive research, we began to feel load was rejected by a local sawmill. With bed stands roughly 3 feet tall, with a steep increasingly comfortable with the poten¬ our fresh knowledge and free resources, edge for planting. A simple approach to tial of hugelkultur. We discovered that we were ready to begin. hugelkultur is: 1) pile up large amounts of the method has been used for centuries heavy organic material, such as logs and and has shown tremendous success in a I must confess, during the beginning limbs; 2) cover the pile with topsoil or variety of regions. We came across Sepp stages of construction, even my wife said compost; 3) top off the pile with a solid the food forest had begun to look “hid¬ layer of mulch. Over time, the organic eous.” It was hard for me to argue. It was material will begin to break down and something none of us had seen before. absorb rainwater. The composting process Several neighbors asked if they could haul within the raised bed will release heat, away the logs for use as firewood. Still, nutrients, and evaporated moisture. Along we stayed focused on the larger picture, with these benefits come added dimen¬ knowing that this was the most resource¬ sion to the garden, increased planting ful long-term approach. surface, and ease of access for harvesting and pulling weeds. We pressed on, and with the help of our fierce volunteer crews, we built more than Initially, we had many doubts concerning 15 hugelkultur raised beds. Each of these the viability of this method. In the Pacific beds (individually named after a Cascade Northwest, downed timber is a valuable mountain peak) has created an environ¬ commodity. Many households rely on ment for dozens of fruit trees, nut trees, wood-burning stoves to get them through and berry shrubs. We have combined the prolonged wet winters. How could these with a wonderful mix of flowers, we justify burying this needed fuel? If we herbs, and annual vegetables. Through the did decide to bury it, would the process use of hugelkultur, our little food forest actually work? Was this just some idealist Holzer, who was able to grow crops at has begun to take on the essence of a natu¬ theory we stumbled upon while surfing 3,500 feet above sea level in the Austrian ral forest edge—lush and vibrant in its the internet or a legitimate gardening Alps. We saw mounds adorned with fruit glory, practice ? How about the aesthetics ? Was trees, annual vegetables, and wildffowers. there any way to make a mound of rotting Coincidentally, we received an unex¬ Justin Henderson is the former executive lumber and soil look eye-catching? pected donation from a logger, whose director of Harvest House. Northwest Horticultural Society A STUMPETTE OF MY OWN Words and photos by Greg Graves Inspiration and opportunity don’t usually occur at the same time but when they do it can be quite fun. A stumpery is a Victorian-era type of fern garden that uses the root stumps of trees as an architectural element. Years ago, my friend Pat Riehl created a stumpery on Vashon Island. A few years later the Hardy Fern Foundation decided to do a stum¬ pery as their signature garden. Both stumperies contain about 150 stumps on about an acre of land. I used to carpool to work with Richie Steffen, who was on the board of the Hardy Fern Foundation and is currently NHS president. Our carpool met close to where HFF was building their stumpery. Because of this we were able to stop occasionally and watch the progress. John van den Meerendonk, a past president of HFF and a principle designer of the garden, was usually on hand directing the operation. It was an amazing process to watch the stumps being strategically placed and then planted with ferns and companion plants. Some of those stumps weighed up to 10,000 pounds. It has now been several years since the initial planting of these two stumperies, and the gardens have become very magical places. Because of the natural elements, they appear to have always been there, looking just as they do now. I try to visit them whenever I get the chance because they are such unique gardens.