In the fall of 2010, I began the process of turning the nascent collection of Primula growing at the newly formed Jensen-Olson Arboretum in Juneau, Alaska, into a national collection for the genus. Before taking the position as Arboretum Manager in 2007 and moving to Alaska from the Lower 48, I had relegated primroses to the category of “disposable” annuals purchased at the big box stores. I was pleasantly surprised to see the diversity that Caroline Jensen, our founder and benefactor, had planted. With such opportunity for diversity, and as a compulsive plant collector, I was hooked! While learning Juneau’s near-perfect, cool, maritime climate for Primula cultivation, I set out to find as many species and cultivars as I could which would bring new colors, morphology, and bloom time to the existing collection. During that acquisition process, I attended a plant collections symposium hosted by the American Public Gardens Association. I happened to meet the Director of the Plant Collections Network; she encouraged me to apply for national collection status. 

Caroline had approximately 30 species and cultivars when I arrived in 2007 - quite a foundation for future growth! Upon receiving National Accreditation^TM status for the genus (2012) I had approximately 65 under cultivation. In the following years, that number climbed to over 200…and that number could have been substantially higher if all the seed that I brought in had germinated, or had been correctly identified. It took multiple attempts to get both P. pulverulenta and burmanica into the Collection. To accommodate the ever-growing Collection, new bed space had to be created. I selected an area that I thought would be good for new species, but soon found out that Mother Nature had other ideas… The last two years in Juneau have seen radical departures from what has historically been considered “normal” weather. In 2019, Juneau experienced its hottest, driest year on record. I had to irrigate the Arboretum for 50 consecutive days to keep the collections alive. Plumbing infrastructure at the Arboretum supports only a single source of water running at any given time; therefore, it takes 4.5 days to water the 3 acres under cultivation. If a plant is flagging due to hot, dry conditions and it’s 3 days away from its next watering, it just has to wait its turn. Many of the Sino-Himalayan plants suffered as a result of that scenario. Watering a coastal temperate rainforest for that amount of time was inconceivable just a few years ago. Many of the plants that showed problems with drought conditions in 2019, either failed to appear or did not bloom in 2020. One of our largest swaths of P. japonica failed to flower this year. Other non-blooming species during 2020 included P. aurantiaca, beesiana, bulleyana, capitata, chionantha, cortusoides, firmipes, hoffmanniana, ioessa, jesoana, lutea, polyneura, pulverulenta, rusbyi and waltonii – an incredible number of species which have annually bloomed since initial planting. The species that did not survive the 2019 summer conditions were P. apoclita, cernua, concholoba, deflexa, flaccida (one of my favorites…), geraniifolia, halleri, longipes, macrophylla, maximowiczii (which is, sadly, short-lived anyway…), prolifera, violacea, and watsonii, The unusual heat also affected the quantity of seed I was able to provide the 2019 APS Seed Exchange; it was the poorest seed-collecting season during my tenure at the Arboretum.

2020 was the exact opposite of 2019. Juneau was one day short of the wettest summer ever recorded. One could count the number of dry days from the beginning of June to the end of August on 2 hands… This long, wet stretch affected the quantity of seed that was set due to the lack of pollinators. Despite the unusual weather, some species didn’t seem to mind. P. matthioli and vialii didn’t seem fazed and produced an abundance of seed. The cause of that is worthy of further study.

As early as 2016, our winter weather began to change. No longer was the snow adequately deep to serve as winter mulch, nor was it in place for the entire season.  This played out the forecasts of some of the climate models - Southeast Alaska’s winters are forecasted to be warmer and wetter. We also are experiencing more freeze-thaw-freeze cycles during the winter months during periods with no snow on the ground. The past couple of winters, December has been warm and mild with plants either not going dormant or breaking dormancy and beginning to grow, only to be hit with single digit temperatures. Covering high value plants for the winter with spruce boughs or burlap bags does lend some winter protection, but that has shown to be inadequate when temperatures fluctuate from 45F/7C to 0F/-17C over just a few days’ time. One of the species that has suffered the most due to that cycling is Primula juliae. We used to have beautiful, huge, blooming mats of these, but now, they are greatly reduced and barely flower. 

So what will this all mean for the Collection? Good question! Diversity will certainly be affected as well as the ability to find and grow new species. Perhaps the focus will shift to only core species with possibly more cultivars (a shift that would sadden this plant geek). Another possibility for the Collection is to collaborate with other public gardens that are in similar climatic zones to form a multi-site collection. Other national collection holders successfully follow this PCN-allowable format. Examples of these are the oak, maple and magnolia collections. For primrose, institutions across Canada and Western Washington are possibilities for this venture. Having a source of backup plant material is also an option. Local growers with different microclimates could make identified species reliably available for replacing ones that have perished at the Arboretum.

That all of course, will be up to the new manager of the Arboretum. After 13 ½ years at the helm, I have retired (as of early December) and moved to Oregon to enjoy different pursuits. It has been the job of a lifetime to have had the opportunity to start a new public botanical institution from scratch, assemble a Nationally Accredited Plant Collection^TM and to learn how to chase bears with a leaf-blower. I wish the new manager Ginger Hudson very well, and hope she enjoys taking the Collection to the next level as much as I have enjoyed building on Caroline’s foundation to establish it.

Merrill Jensen

newly, happily-retired JOA Manager

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After several years of planning, the newly-retired Arboretum Manager is pleased to announce the realization of a dream...well, part of a dream.

For much of his tenure at the Arboretum, Merrill Jensen has longed to produce several mapping-related educational tools. Early on in his tenure, he developed the bed map to be used by staff and volunteers for daily operations. Beyond that, Merrill has hoped for a Visitor Map (to be used by the general public as an orienting tool and to assist with questions) as well as a GPS map of the collections (in support of the plant accessions database and to be used by staff as well as researchers). Pieces of these dreams have come to pass over the last few months. The first JOA Visitor Map is hot off the press as of early December, and close behind it is the first JOA Field Guide. See the Spring issue of TWIGS for all the details including how to get your copy of each new publication.

Merrill still longs for the day when the plant collection will be GPS-mapped, in keeping with public garden curatorial standards, and available by open access...a dream for the Arboretum's future.

In part, the Visitor Map project is supported by an FY21 Grant-In-Aid from the Alaska State Museum.

We are very excited to have Ginger Hudson join our Parks and Recreation team as the manager of the Jensen-Olson Arboretum! Ginger brings fine skills in garden design, landscape maintenance, writing, education, and business and retail management. She has worked at the Alaska Botanical Garden, the American Botanical Council, the Lady Bird Johnson Wildflower Center, and has cared for the Pioneer Home Gardens in Anchorage along with many other gardens in Anchorage and Texas. 

Michele Elfers

Deputy Director

Parks and Recreation Department

City and Borough of Juneau

Heritage Garden at the Alaska Botanical Garden commemorating Anchorage's Centennial;

design and installation by Ginger Hudson

The grand horticultural adventure continues. If you will remember from the last issue, I was working on special projects for the Idaho Botanical Garden in Boise when I heard rumors of a new public garden under development in the Willamette Valley of Oregon. A little searching and I discovered that The Oregon Garden located in Silverton was just breaking ground. The Oregon Association of Nurseries wanted a display garden setting in which to showcase their plant material and was sponsoring the project. They were looking for professional horticulturists and I applied. I soon joined a team of dedicated people in transforming a very large and defunct horse ranch into a public garden and when I arrived, I quickly learned the value of good rain gear. I was rapidly promoted to Collections Manager and was responsible for working with the design team of landscape architects sourcing plant material for the project and creating the plant database to track all the incoming plants. It was quite satisfying to watch so many muddy plots transform into manicured garden spaces. Kelly and I had envisioned staying from then on in Oregon, but that was not to be. Unfortunately, just a few years into its growth, the project and associated funds came under mismanagement, and faced a $7 million shortfall. One afternoon after an all-staff meeting, many of us were permanently laid off. Though initially, it felt like a gut punch, the news set in motion a path that would lead to better things. 

The next step in our grand adventure took us to the Bay Area where I was the Director of Horticulture at the Elizabeth F. Gamble Garden in Palo Alto. Going from the rolling hills of the Willamette Valley to a metro area that we shared with 7.5 million people was a bit of a shock. Gamble is only a mile away from Stanford University and many of the garden volunteers were retired faculty or staff. One of my favorite “weed pullers” was a retired astrophysicist who had worked directly with Stephen Hawking…this astrophysicist just wanted an opportunity to unplug and work in the soil for a few hours. Many of Gamble’s garden beds were in need of refurbishing with plant material that was more appealing for visitors. New cultivars of roses (my least favorite plant) were added to the Rose Garden, a historic Iris bed (Miss Gamble’s favorite flower; do we see a pattern starting here?) was refurbished, and I directed the creation of a Salvia bed with the author of a monograph on the species as well as a California native plants bed.

As mentioned earlier, Alaska continued to beckon and we traveled north (to interior Alaska) for a couple vacations. While researching a possible vacation to SE Alaska, I literally stumbled across the position announcement for the first manager of a new arboretum in Juneau!…on the CBJ home page! I was surfing the internet while eating my lunch and almost fell out of my chair. I had finally come across the job posting I long awaited. I immediately called Kelly who was in Berkeley finishing her Master’s degree…she did not hesitate and said, “Apply; let’s go on another horticultural adventure.”

The day I arrived in Juneau for the on-site portion of the continuing interview process, in March of 2007, was the day that the annual snowfall record was broken. The 3-day interview process happened downtown and a site visit to the Arboretum at Mile 23 revealed a very short walking path through 4 feet of snow. CBJ staff continually told me that there were plants under the snow and that the strolling areas were longer than a 1-2 minute walk. My resume included a strong background in public gardens with increasing responsibilities…just what the search committee was seeking with the start of a new public garden – a couple weeks later I was offered the position. I loaded up one of our cars, boarded the MV Columbia in Bellingham, and headed north. I arrived at 4:30 in the morning on May 7^th and drove Out The Road to the next (and best!) chapter of my career in public horticulture. 

I could not have dreamed a better position in a better location than being charged to fulfill Caroline Jensen’s vision and gift of her property and resources to become a public botanic institution. I hope she is pleased with the progress of this chapter in the Arboretum’s history.  

Merrill Jensen

newly, happily-retired JOA Manager

(Editor’s note: see the Autumn issue of TWIGS for the beginning of the story…)

Early this year, I received a message from the Lead Scientist at the Woody Landscape Plant Germplasm Repository based at the U.S. National Arboretum; the message came through our partnership with the Plant Collections group of the American Public Gardens Association. The U.S. National Arboretum was making surplus, wild-collected plant material available to partner institutions for enhancing collections. As a compulsive plant collector, I was instantly intrigued about the possibilities for the Arboretum. I downloaded the list and looked for material that would have the best possible chance for robust growth in Juneau, and which would meet the criteria set out in our Plant Collections and Acquisitions Policy. Four plants made the cut: Acer davidii (David’s Maple), of which we already have a scrappy, but healthy specimen; Cercidiphyllum japonicum (the Katsura tree), one of the best fall foliage plants at the Arboretum; Picea orientalis (the Oriental spruce or the Caucasian spruce); and Pinus armandii (the Chinese white pine).

I had specific reasons for choosing each of these, but also, collectively, they were chosen because they were grown from wild-collected seed, gathered during sponsored expeditions, and included complete provenance data for each plant. This data is essential for a botanical institution whose mission includes research and education, as provenance data becomes part of the plant’s metadata file in the plant database, and provides insight into plant distribution, propagation, population biology, accurate identification, and cultivation. The maple, katsura, and pine came from seed gathered during an expedition sponsored by The Arnold Arboretum (the mothership of North American arboreta) of Harvard University; this expedition included Chinese colleagues of Arnold staff, who together form the North America-China Plant Exploration Consortium (NACPEC). This group boasts many goals; chief among them is “the primary scientific documentation of botanical diversity” and the group has been building on that goal for 30 years. The spruce was collected in the Republic of Georgia by Marina Eristavi, Lead Botanist from the Institute of Botany, Tbilisi, in collaboration with the Chicago Botanic Garden.

The trees grown from seed collected in China have interesting stories associated with the original collectors, but the Katsura’s story really became compelling when the provenance data arrived. It was noted in the collection information from NACPEC that the tree was a complex of trunks which had resprouted centuries ago. Katsuras will resprout and regenerate if they are cut down - an interesting cultivation side note for sure, but it got better. NACPEC collaborators stated that the same tree from which the seed had come, was photographed in 1910 by the great plant explorer Ernest Wilson (a plantsman worthy of a separate article).  Hmmm…could I find this photo?! I really wanted to see what that tree looked like. I was able to find that photo (thank you, Google!) along with one that was recreated from the 1910 shot with the crew from The Arnold. For the photos, full story, and one of the best plant tales I’ve ever read, see it in its entirety (pages 5 – 8). It is estimated that this tree is over 500 years old and could be as many as 1,000 years old. What an amazing plant!

Now, the Jensen-Olson Arboretum has a tree (although currently only 2’ tall) in its collection…grown from seed of that tree living in the mountains of Sichuan, China…collected on an expedition undertaken by The Arnold Arboretum, the leading arboretum in the country…by Michael Dosmann, Keeper of the Living Collections…a position held in the 1920s by Ernest Wilson…and then shared with the U.S. National Arboretum…truly a tale of a tree….

So often, visitors both local and from afar, ask about the pale green plant material hanging from various trees throughout the Arboretum. Soon, a new interpretive panel will be installed highlighting these green novelties. With special thanks to Chiska Derr for providing content expertise, the Arboretum is pleased to offer this new educational tool. The panel is complete and will be installed in the early Spring.

Other frequently asked questions center around the special colored dandelion under intentional cultivation at the Arboretum (well known by long-time, savvy Arboretum visitors), and the metal wheels on display near the native beds. Signs are in production to interpret these interesting elements of Arboretum and will also be installed in 2021. Come see the new additions!

In the Spring of 2008, about a year after arriving on the job, then-manager Merrill Jensen wanted very much to share Arboretum updates with the visitor community. He conceived an idea to share an occasional email update, and decided to name it TWIGS. For several years he wrote and distributed TWIGS to a growing list of interested folks; I provided editorial assistance, and TWIGS served as an early facet of outreach and education in support of the Arboretum’s mission.

Later, with the establishment of Friends of Jensen-Olson Arboretum (FJOA), and a growing membership, we continued the practice of email updates and began to include event details. In early 2016, the Arboretum and FJOA pursued the next level in communication with our premiere, (hosted) TWIGS…a standardized and branded formal newsletter, distributed on an established schedule, with updates specific to Arboretum activities as well as to its place in the wider (national and international) horticultural community.

Producing the issue here before you – my last as editor – I am reminded of those very early days sitting with Merrill in front of an email of a few sentences, maybe 1 or 2 photo attachments, and the absence of links or logos. What a joy to have launched this outreach effort and stewarded its development over these 12 years.

The mission of a public garden is a powerful and creative force, but in my opinion, only meritorious if borne out in effective communication; with TWIGS, I hope we have provided informative and inspirational news and updates. And now, poised at the promising edge of a new chapter in its growth, the Arboretum and its community will benefit from new developments in outreach and education; I look forward to watching these exciting changes and assisting when possible.

        Mission Statement              

 The vision of the Arboretum is to provide the people of Juneau a place that both teaches and inspires learning in horticulture, natural sciences and landscaping - to preserve the beauty of the landscape for pure aesthetic enjoyment - to maintain the historical and cultural context of the place and its people.

                                                                                                                         Caroline Jensen 

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  Friends of Jensen - Olson Arboretum Board Members