Announced at the Truro, Nova Scotia, Annual Meeting
(The Awards committee consists of Cyndy Cromwell, chair; Judith DuMont, Don LaFond, and Rosemary Monahan)
Award of Merit
Betty Spar (Arizona) submitted by Cyndy Cromwell
Betty Spar has been an active member of NARGS since 1991. She’s been a regular at NARGS AGM’s and served in a variety of roles. Betty has chaired the Awards Committee, organized NARGS study weekends, and developed and chaired a NARGS Book-of-the-Month Review program. Betty has served on the NARGS Board continuously since 2011 and is a Life Member.
In 2017, she was elected NARGS President. During her term, Betty was actively engaged in fund-raising for NARGS. Her greatest success was in obtaining a commitment from a NARGS member for multi-year funding of the Traveling Speakers program.
In the face of rising printing bills, Betty worked with NARGS Quarterly editor Joseph Tychonievich to reduce costs by switching to another printing company. This action has allowed NARGS to continue printing four hard copy issues every year, to the delight of many members.
Betty came to NARGS with a solid horticultural background. She retired as Chief Administrative Officer at the United States Botanic Garden in Washington, DC, having worked previously as a commercial nursery propagator and then as Assistant to the Curator of the T. H. Everett Rock Garden at the New York Botanical Garden.
Betty’s enthusiasm for horticulture and NARGS continues unabated. Now living in Tucson, Arizona, she has become a long-distance member of my own Piedmont Chapter. She’s a regular reader of the newsletter, attends meetings via Zoom, and participated in the chapter bulb sale. Luckily for NARGS, Betty remains active on the Board, always bringing with her a ready smile and encouraging words.
Paul Spriggs (British Columbia) submitted by Bobby Ward
Paul has been rock gardening for nearly a quarter of a century and has been building crevice gardens for seventeen of those years. He was mentored in his crevice garden knowledge by the renown Czech gardener, Zdeněk Zvolánek. Paul has worked alone or in collaboration with other crevice gardeners to install both large and small crevice gardens in private gardens and in public spaces. In spring 2022, he and others enlarged and significantly extended an existing crevice garden in Port Townsend, Washington, at Far Reaches Botanical Conservancy, whose goal is to protect vulnerable high elevation ornamental plant species suited to cultivation at lower elevation in a crevice garden. Paul also collaborated on the installation of a crevice garden and demonstration installation in Portland, Oregon, in June 2022, during a meeting of the American Public Gardens Association, a project co-funded in part by a NARGS Norman Singer Endowment Grant. Paul is a past president of the Vancouver Island Rock and Alpine Garden Society, the oldest rock garden society in North America. He is the co-author with Kenton Seth of the first book written about the North American style of crevice rock gardening, titled The Crevice Garden published in 2022. He is a widely sought-after speaker and during the COVID pandemic gave many Zoom talks to gardening clubs in North America and abroad. In his free time, he is passionate about wildflowers, and he collects and grows them in his various gardens in his hometown in Victoria. Paul’s boundless energy and enthusiasm for rock gardening is a major asset to the North American Rock Garden Society.
Darwin Carr (Nova Scotia), submitted by Jim Sharpe and Todd Boland
Darwin, more than any other horticulturalist, has worked with Bernard Jackson to make the Dalhousie Rock Garden a reality. As gardens coordinator for the agricultural campus for over thirty years, he worked with Bernard Jackson to implement his vision for the original rock garden in the 2000s. He was key in the forming of both the “Friends of the Garden” group to maintain the rock garden and the Nova Scotia Rock Garden Club. He maintained the garden when Bernard returned to Scotland and was the key liaison with the campus for the expansion of the limestone garden from 2018-21 after Bernard’s return from Scotland.
Darwin has made a critical contribution to the Nova Scotia Rock Garden Club as its ongoing Treasurer. He has organized bus trips, both for the “Friends of the Garden” group and for bringing members to NSRGC meetings. After 34 years on campus, he retired in 2021 from his role as horticultural coordinator at the Dalhousie Agricultural Campus Gardens. He is very active as owner/manager of a tree trimming and removal company. With the damage from Hurricane Fiona last September, Darwin has been busier than ever before.
Darwin, thank you for your commitment to growing rock garden plants and the development of our rock garden club in Nova Scotia.
Marvin E. Black Award
Laura Serowicz (Michigan), submitted by Don LaFond
The first time I went to see Laura Serowicz’s garden I asked, as one will, what plant is that? In my garden I would stutter something about the blue jay stealing the label and point to a pine marten running across the yard, but not Laura. She got out her phone while looking at the sign with the number of the bed then to the number on the label and described from her phone what plant, when and where the plant was obtained including the year (perfectly grown, I might add). That is the kind of person you want to organize and plan our beloved NARGS Seed Exchange.
The NARGS seed list is 3000-4000 different taxa. Reading through and selecting the seeds you want from that list is a great education in itself. Can you imagine what it must be like to be responsible for thousands of packets of seed sent to your mailbox? Then have to sort and catalog all those seeds. And have to make sure their names are up to date (taxonomists!!) along with dozens of other nifty things, and then send them out to the chapters for their part in the process. Planning? Organizing? Yes to both! This is what Laura has done every year for 18 years so far. Thank you, Laura.
I, as with most rock gardeners I know, first joined NARGS because of the seed exchange. So you can well see how many members Laura has helped reach their potential in the plant world, and I’m one. For all these reasons I nominate Laura Serowicz for the Marvin Black Award.
Roslyn Duffus (Nova Scotia), submitted by Jim Sharpe and Anna Leggatt
We are pleased to nominate Roslyn Duffus, chair of the Nova Scotia Rock Garden Club (NSRGC) and co-chair of the NARGS 2023 Conference and AGM for the Marvin E. Black Award. Roslyn has been chair of the NSRGC for over twenty years, organizing monthly meetings on the third Saturday of the month from January to November. The club is unique in that its meetings move between three locations: the Truro Agricultural Campus with the large rock garden and the Friends of the Garden members, the Annapolis Valley with the greatest amount of horticultural activity in the Province, and the Halifax region with the largest population of Nova Scotia. Each meeting includes a social time, often over lunch, a presentation and question period and often local field trips or plant exchanges. Different people attend based on the topic, location and activity for the meeting. With the meeting restrictions of the COVID pandemic, Roslyn was instrumental in NSRGC using Zoom for monthly meetings. This has continued even with the return of in person meetings which increases the participation and geographic reach for the monthly meetings.
In 2018 Jim Sharpe joined Roslyn and others from NSRGC to attend the NARGS Conference in St. John’s, Newfoundland. It was an excellent conference with over 100 in attendance from across North America. I asked why we hadn’t hosted a NARGS conference in Nova Scotia, Roslyn informed us that we were asked to host the conference, but we declined, so Newfoundland hosted their second NARGS conference as they already had hosted in 2006.
The opportunity came up again a few years later when Panayoti and Todd advised that it was “our turn” to host NARGS. Roslyn, in spite of worrying at night about all the details, immediately arose to the challenge of arranging local and international speakers, planning field trips and garden tours, and considering all the arrangements. She scouted out Brier Island for a post conference tour and made all the arrangements herself. NARGS 23 would not have taken place in Nova Scotia without Roslyn’s vision and leadership.
Roslyn lectures on a variety of subjects, especially seeds. Her Zoom presentation for NARGS ROCKS last fall is still available for members. Her presentations on growing native plants, native azaleas from seed, can be found on line. She is an active member of the Ontario Rock Garden and Hardy Plant Society (ORG&HPS), attending and contributing at meetings via Zoom. She also donates to the seed exchanges.
Frank Cabot Public Garden Award
The Dalhousie University Bicentennial Botanical Garden (Nova Scotia), submitted by Todd Boland
Dalhousie University Bicentennial Botanical Garden is located on the campus of the Faculty of Agriculture in Bible Hill, Nova Scotia. The grounds of the Dalhousie Faculty of Agricultural, formerly known as the Nova Scotia Agricultural College, encompasses some 26 acres and contains a number of horticultural features including a pollinator garden, rock wall, Alumni Gardens, herb garden, heath and heather garden, a substantial rhododendron display and a spectacular rock garden. To celebrate Dalhousie’s 200th anniversary, the grounds of the Bible Hill campus were officially named the Bicentennial Botanical Garden.
From the perspective of NARGS members, the rock garden is perhaps the most significant feature. The rock garden’s initial construction began in 2002 and was designed by Dr. Bernard Jackson, retired director and designer of the Memorial University of Newfoundland Botanical Garden. Much of its upkeep is maintained by a large group of volunteers. The rock garden covers just over one-half acre of land and is situated on a south facing slope. It consists of a rock face, two dry streams, a gravel scree bed, peat bed and woodland garden. The rock face area is quite hot, featuring sun-loving and drought-tolerant alpines along with a significant collection of hardy succulents. The dry streams are in two gullies, designed to look like old, rock lined erosion gullies. These gullies provide a damp area for specialized alpines but also has a practical function in funneling and carrying away, any excess rainwater from the garden. The scree houses tap-rooted plants that require exceptional drainage. Scattered throughout the garden is an impressive collection of dwarf shrubs and conifers. The peat garden features Ericaceous plants and other acid-loving plants. The woodland section is a transitional area between the newer Courtyard Trough Garden and the rest of the rock garden and is comprised of small to mid-sized deciduous trees and conifers that provide habitat for shade loving woodland plants.
The original rock garden contains 800 tons of local red granite and features impressive stone steps that help traverse the undulating nature of the rock garden. The garden also features two cedar bridges constructed by students in their wood construction techniques class.
Directly east of the original rock garden and woodland garden lies the impressive Courtyard Trough Garden. The trough area was built in 2003 with grant support from the Norman Singer Endowment Fund provided by the North American Rock Garden Society. The physical construction of the courtyard was started as a class project with the third year horticulture students in landscape project management. The area features natural stone walls, a limestone courtyard, crevice gardens and hand cut natural sandstone alpine troughs. The courtyard area is popular with local photographers as a backdrop for weddings and graduations. The east entrance to the courtyard is framed by an eastern white cedar shingled arbour structure which was also constructed by college students. Local rock garden enthusiasts were anxious to help with the courtyard and other aspects of the rock garden and through Bernard Jackson’s encouragement, the Nova Scotia Rock Garden Club was started, soon becoming a chapter of NARGS.
In 2018 there was an extensive expansion made to the rock garden. Utilizing 450 tons of limestone, a new rock garden was constructed containing low cliffs, talus slope and scree, a crevice garden, limestone pavement garden and an outdoor classroom. To finish off this new expansion, students from the landscape project management class constructed a man-made pond and bio swales to control water runoff from the nearby parking lot. In 2019 an alpine meadow was added.
This rock garden is one of the two largest rock gardens in Atlantic Canada and is one of the most significant horticultural features in Eastern Canada. The Bicentennial Botanical Garden was described by Darwin Carr, retired horticultural technician and Bernard Jackson’s “second in command” in the Fall 2022 issue of the Quarterly.
Linc and Timmy Foster Millstream Garden Award
Kobre/Denson Garden, Special Garden Category (New York), submitted by Carol Eichler
I wish to nominate Marlene Kobre and her partner and help-mate, Ron Denson. Several things make this garden and its gardeners remarkable. First, the garden displays an amazing harmony of form. It is very soothing to the eye and the soul. Marlene has an intuitive designer’s eye. Second, it is an inspiring garden. I still remember the first time I visited this garden nearing 40 yeas ago and it was jaw-dropping back then. If memory serves, this garden at that time had not one but two water features and a modest rock garden along with mixed borders. Over time, it has only gotten better. Third, she is a great observer and caretaker – providing each plant with the requirements it needs not just to survive, but to thrive. All these qualities in my mind comprise a great gardener. And in my opinion Marlene has truly earned special recognition for her efforts. Those who attended the 2022 AGM in Ithaca had a chance to visit this garden and would presumably agree that the Kobre/Denson garden is worthy of this recognition.
Marlene’s interests, like most gardeners, have evolved. Having bought her home some 40+ years ago, she first had to prepare her garden beds by removing numerous mature trees to open up the landscape. Basically the backyard was a forest that had to be cleared. There wasn’t much to be done with the tall conifers along the neighbors’ boundary lines so rhododendrons were a logical first plant selection. Her garden design progressed from there to include tree peonies, moved on to Japanese maples (and continues to be one of her obsessions to this day), rock gardens and troughs – Kabschia saxifrages her current challenge – and outdoor patio arrangements of tender perennials in pots. Terraced beds include more rock garden plants such as gentians and primrose that prefer a more sheltered location.
Regular visits to New Mexico have greatly influenced her collection of potted succulents. Continuing to add new beds and new plants, her most recent additions have been a second rock garden, a dwarf conifer bed, and always more, more, more Japanese maples. She always manages to find room for one more plant or one more garden bed. And through the seasons, each plant has its time to shine.
Her second rock garden was installed (in 2017 perhaps) and is loaded with gems and rarities. One would never judge by the establishment of the plantings that this garden is relatively new. Sempervivums and daphnes are particular favorites, to name just two. I would be remiss if I did not mention Ron’s contributions. He has become increasingly involved and devoted to developing – and maintaining - these gardens.
Aside from her own garden Marlene has done much to inspire members of the Adirondack Chapter NARGS as chair of our Plant of the Month, a position she has held for the last several years. She chooses plants appropriate for rock garden, trough or woodlands, which the chapter in turn sells at subsidized prices to members at our speaker meetings. In assuming this role, she always supplements her selections with a well-researched newsletter article that includes plant description, cultivation requirements and more. In so doing she has vastly improved our members’ plant inventory and knowledge while encouraging more of us to try our hand at rock gardening.
Garden of Lee & Arie Vanspronsen, Alpine Rock Garden Category (Ontario), submitted by Anna Leggatt
This jewel of a garden is situated in the outskirts of a town close to wooded ravines, near Lake Ontario and the Niagara Escarpment. It seems very small as you pull in off the street. In the spring, the first stop is by a shady woodland bed which is filled with various colours of Corydalis solida, bright blue Hepatica, Helleborus, emerging Paeonia shoots and spring bulbs.
An espaliered fruit tree forms a division before you reach a large bed filled with hardy cacti and other succulents. This is low key in April. The various forms and colours are much appreciated by July. The working area is behind with an alpine house cum propagation greenhouse. It is filled with many treasures such as dwarf forms of grafted Ginkgo.
The garden opens up, revealing a large and small crevice garden, a tufa mound planted with Kabscia Saxifraga, many troughs with dwarf trees, rare conifers, Clematis, unusual tender plants and many more. A dwarf Hosta collection is displayed in pots. These can be moved to find the best shady position. The array of unusual plants may distract you from watching your feet. There are so many small features exquisitely planted that might trip you up! More are continuously added!
Larger plants are pruned and trained to maximize their beauty and also to make more space for other delights. Pots of Agave and other succulents are raised up so you can see their form.
I particularly admired a lovely blue Synthyris lanuginosa flowering in the crevice garden in April. The crinkly leaves remained attractive after flowering. Low, variegated Sedum takesimense ‘Atlantis' was eye-catching in July. Its bright green leaves had wide creamy margins with hints of pink. Luckily a plant was for sale!
This collectors' garden has won several awards from the City of Hamilton and is a favourite stop on garden tours.
Marcel Le Piniec Award
Sue Milliken and Kelly Dodson (Washington), submitted by Don LaFond
The Marcel LePiniec award is the second oldest award given by NARGS, since 1969. So as you can imagine there are some fairly illustrious names on the list. I think the next addition to that list should be Sue Milliken and Kelly Dodson, the dynamic duo that is Far Reaches Farm and Far Reaches Botanical Conservancy. The award is given for a nursery person or persons, propagator or plant explorer engaged in getting plants to gardeners.
Have you looked at their catalog, or listened to a talk that Sue and Kelly performed? I’m not sure who has more fun, them or their audience. They propagate everything in their nursery themselves. They do this by traveling around the world to collect the rare and endangered seeds, bulbs, and plants to propagate the rarities. I would say that covers the propagators and plant explorers part of the award.
Making them available to the public through their nursery would be a big enough project in itself. But they also needed something to do in their spare time. So they created a botanical conservancy to try to keep these rare and endangered chlorophyll life forms alive in perpetuity. This I think is exactly what the Le Piniec award is for. And just so you realize they have not forgotten us rock gardeners, take a look at the giant crevice garden, that rivals many public rock gardens, that they had built on sight at Far Reaches Farm. It is currently being filled with alpine plants, desert plants, and other small gems from around the world. I can't wait to go there and drool. For all these reasons I nominate Sue Milliken and Kelly Dodson for the Marcel Le Piniec Award.
Esther Wrightman (New Brunswick), submitted by Don LaFond and Tony Reznicek
Don LaFond: Esther Wrightman is the owner and operator of Wrightman Alpines, located in St. Andrews, New Brunswick. Her nursery grows thousands of species and varieties of alpine plants. Her mail order catalogue lists over 700 alpines which they ship to enthusiasts, many of them NARGS members, throughout Canada and the United States. In fact, in North America, they are among the largest mail-order nursery for alpine plants.
The nursery was originally started by her father, Harvey Wrightman, in 1985, on a farm outside the small town of Kerwood, Ontario. In spring 2014 the nursery moved to St. Andrews, New Brunswick. In 2015 Harvey was diagnosed with terminal cancer and he passed away in December of 2016. Shortly before his passing he passed the running of the nursery over to Esther. Thankfully, having worked with her father for over 20 years, she was well versed in alpine plants, how to grow them, and their propagation.
Today the nursery consists of three greenhouses: two are left unheated during the winter and used to store plants that will be ready for sale in the spring. The third greenhouse is kept frost-free in winter and used for the propagation of alpines. The nursery also has an extensive display garden featuring alpines, woodlanders and dwarf rhododendrons and other ericaceous plants.
Tony Reznicek: It is my great pleasure to support the nomination of Esther Wrigtman for the Marcel Le Piniec Award. I go back a long way with Esther - remembering her when she was a small child at her father’s side when the nursery was still in Kerwood, Ontario, close enough to Ann Arbor to visit regularly. Even there, she had begun to be a force in the nursery for diversity and aesthetics. She played a much greater role in re-forming the Nursery after the family moved to a beautiful setting on Brandy Cove, on the north edge of St. Andrews, New Brunswick.
Growing up in the nursery business, it was natural for her to continue in it after her father passed away much too soon. She has developed Wrightman Alpines into the premier alpine and rock garden plant nursery in eastern North America, if not the entire continent. I am so grateful that she takes the trouble to ship to the U.S. in addition to within Canada! For anybody that has had a chance to visit, the display gardens are full of lovely things including treasures that we all hope will be made available soon in their sales offerings.
Besides vegetatively propagated stalwarts, a substantial number of Wrightman Alpines offerings are originals grown from various seed collectors worldwide. Some of the highlights of their offerings include a wide range of choice Androsace species (dozens over the years), Dianthus species, Draba species, and various gentians, to note a few. Vegetatively propagated specialties are also an important element. This includes many cultivars of Calluna, Dwarf Daphne, and most especially a huge selection of Primula (especially Primula allionii and Primula auricula cultivars) and Saxifraga cultivars, including newer Karel Lang crosses of Porophyllum Saxifrages. The selection changes every year, and it is always exciting to see what new things are available with each new year.
Experimenting with growing rock garden plants in North American conditions was always part of the thrust of the nursery and Esther has continued that thrust. This includes growing and selling Porophyllum saxifrages in small tufa blocks, experimenting with crevice gardening long before it became popular, and especially working on growing outside some of the very difficult alpines. Jankaea and Dionysia, for example, I first saw at Wrightman Alpines.
With so many nurseries having closed in recent years, Wrightman Alpines under Esther has had a starring role in keeping diverse, exciting, and new rock gardens plants available to North American gardeners.
Carleton R. Worth Award
John Massey (West Midlands, U.K.) for My World of Hepaticas, submitted by Bobby Ward
This award is being presented this year to John Massey, owner of Ashwood Nurseries, in recognition of the publication in 2022 of “My World of Hepaticas,” a monograph, the first in the English language, that is the result of 25 years of dedication in growing, studying, breeding, and selecting forms of a genus that is not even native to the British Isles. Thus, he has relied on numerous trips abroad to observe hepaticas in the wild, which has connected him with other hepatica enthusiasts worldwide and provided him the opportunity to drop in tales of his travels. His book is a joyful, passionate journey, in fact, “a huge adventure story,” he writes in his long devotion to hepaticas. The 296-page weighty book is delightfully filled with copious photographs, a warmly written chapter on mentors and friends who shared his enthusiasm, and a chapter contributed by collaborator, Tomoo Mabuchi, on up-to-date taxonomy and cytogenetics of the genus Hepatica. In brief, this finely written, handsome book will inspire its readers to seek out this plant and grow it in your own trough or garden.
Paul Spriggs (British Columbia) and Kenton Seth (Colorado) for The Crevice Garden, submitted by Don LaFond
I was introduced to Kenton Seth at a NARGS conference, as one of the young people that will take rock gardening into the future. That day Kenton told me about a little adventure he had, where he went to find Janis Ruksans in Georgia (Caucasus). Ask him about it when you meet him one day. Paul Spriggs and I also met at a NARGS conference. He invited me to have lunch with him. We talked about Saxifrages, and Rex Murfitt, two of my favorite people. I knew then that I had met two guys who were as hopelessly infatuated with rock gardening as I.
Several years later they published a book. The Crevice Garden (2022) by Kenton Seth and Paul Spriggs. I think this book is important to the future of gardening in two ways. “The Crevice Garden”, by explaining the history of how crevice gardening came about and Kenton and Paul’s personal experience on how to do it, inserted itself squarely into the ecological conundrum of wanting to have a beautiful place to live in but not use up scarce resources to do it. At the same time giving rock gardeners a good example of how to take this relatively new idea of “crevice gardening” and make it look like a garden that can sit in its environment comfortably and not be afraid to be the star. These two ideas together have the potential to bring not just rock gardening but ornamental gardening in general into the future. In my estimation they have distinguished themselves in their book The Crevice Garden.
Edgar T. Wherry Award
Adam Black (North Carolina), submitted by Tony Avent
I would like to nominate Adam Black for the Edgar Wherry Award.
Adam is a remarkable plantsman/botanist/conservationist, currently employed as Director of Horticulture and Plant Conservation at the Bartlett Arboretum Headquarters in Charlotte, NC.
Adam’s botanizing focus has been in both Florida and Texas, although he has also worked throughout the Southeast U.S., as well as in Taiwan and New Caledonia.
Adam has built a huge on-line following of the country’s top botanical conservationists, who monitor his near constant discoveries, all documented on-line, as he constantly traverses the southern tier of states. Adam works to both find sites worthy of conservation as well as sharing propagation material with ex-situ conservationists. It’s nothing for Adam to drive four hours each way several times a week to hand pollinate a rare orchid, returning months later to gather seed and send it off for tissue culture propagation. His dedication to rare plant preservation is unparalleled.
Adam works with a number of conservation organizations across the country to track down rare plant species and species previously thought to be extinct. In 2022, he put together the team of International Oak Society members that rediscovered the rare Quercus tardiflora in West Texas. This is one of Adam’s many finds that have extended the known range of some of the country’s rarest native plants.
Adam previously worked at the Kanapaha Botanic Garden in Florida, the Forest Pathology and Entomology Laboratories at the University of Florida, as the Director of the John Fairey Garden in Texas, and as the Program Coordinator for the Smithsonian-led Global Genome Initiative for Gardens.
A few articles on Adam are here:
Geoffrey Charlesworth Writing Prize
Linda Cochran (Washington) for her article Adventures with Castillejas in the winter 2021/22 issue of the Rock Garden Quarterly. By Joseph Tychonievich.
I always learn a lot from articles in the Quarterly, but it is the rare article that makes me completely rethink everything I thought I knew about a genus. I – like most gardeners – thought of the genus castilleja as beautiful but all but ungrowable in cultivation. Linda’s incredible article completely changed all that, as she laid out simply and clearly just what these plants need to thrive, and how easily they can be incorporated into a garden or landscape. Truly a fantastic, informative, and inspiring article, and I am thrilled to recognize it with this award for the best writing in the Quarterly.
Dalhousie Agricultural Campus Bicentennial Rock Garden. By Panayoti Kelaidis.
In gratitude for an outstanding NARGS Annual General Meeting, conceived during the dark days of COVID in 2020 and braving extraordinary weather challenges (Hurricane Fiona in September 2022, drought, and spring 2023 forest fires, to name a few), the Nova Scotia Rock Garden Club of NARGS persisted and prevailed to put on a flawless and joyful conference in June 2023 in Truro. The spectacular Dalhousie Agricultural Campus Bicentennial Rock Garden inspired NARGS to take advantage of serendipity in the moment to provide a grant of $5,000 to further enhance a gem of a garden that was also awarded at the meeting the Frank Cabot Public Garden Award for outstanding public rock gardens. The Cabot award is limited to great public gardens that meet high standards in the creation of rock gardens.