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Jenkins Arboretum & Gardens New Collections
Preserving The Region's Rare and Endangered Species
by Steve Wright, Curator of Plant Collections and Josh Quinlan, Hamilton Educational Fellow - 4/17/2012
2011 marked the 35th anniversary of Jenkins Arboretum & Gardens. Over those 35 years the Arboretum has been transformed from a natural, unmanaged woodland to a living museum of trees, shrubs, ferns and wildflowers. It started with a foundation of rhododendrons, azaleas and other related plants (including blueberries and mountain laurels), but has been slowly expanding. Significant additions came with the creation of a bog garden and wildflower beds and, with the help of the Green Ribbon Native Plant® program, an increased presence of native flora. Perhaps the most important addition however, was a deer exclusion fence which has helped protect these delicate plantings. All of these things have helped the Arboretum become the great horticultural institution visitors enjoy today.
Now, as we enter a new era in the Arboretum’s history, things are about to get even better. It’s time to revisit the garden with renewed enthusiasm and we are thrilled to share it all with you, our members and friends who have helped make this dream a reality.
The horticulture staff has been working on several new initiatives aimed primarily at increasing botanical diversity. We are doing this by either acquiring species that are not currently found in the Arboretum or by acquiring seeds of species that we do have in our collections, but getting them from different sources to ensure genetic diversity.
One of the ongoing goals is to preserve Pennsylvania’s rare and endangered species, so whenever new plants are to be acquired, preference is given to those whose natural populations are compromised. Currently, the collection contains about 50 species that are listed as rare, endangered, threatened, or extirpated and there are several that will be incorporated this year. Among them are the showy Fraser’s sedge (endangered) and fringeleaf wild petunia (endangered), but last fall, our greenhouse volunteer crew cleaned and sowed several flats of rare plant seeds. It may take a few years for these to be ready for the garden, but they are on their way! More specifically, there are three collections currently being developed – ferns, mosses, and native orchids. Each is discussed in further detail below.
Native Orchids
Orchids are among the most beautiful, exotic, and varied groups of plants on Earth. Unfortunately, when most people think of orchids, they envision the tropical epiphytes hanging on the walls of a conservatory. But there are nearly 60 species of native, terrestrial orchids growing wild in Pennsylvania’s wetlands and woodlands and we at Jenkins are working to bring them to the forefront. A native orchid collection was started almost two years ago with the planting of 8 different species including rattlesnake plantain and crippled cranefly, but there are several species waiting in pots to be planted.
Establishing a diverse native orchid collection would be a huge addition to our gardens. From a horticultural perspective, we hope this collection would draw thousands of plant enthusiasts, horticulturists, and nature lovers of all kinds. From a botanical perspective, these orchids add an entirely new family of native plants to our landscape.
From an ecological standpoint, we would be helping to conserve this group of very rare plants whose natural populations are declining or disappearing altogether. And from an educational perspective, this collection would be used to teach the value of native plants, and the importance of species diversity and conservation. Many of those we hope to add demand very specific environmental conditions, and will require a great deal of research so developments might be slow, but we hope that one day in the near future, you will be able stroll the gardens and view the largest, most spectacular known collection of native orchids – all in one place.
Moss
Enhancing a garden with moss is a trend that is becoming increasingly popular with naturalistic gardeners. While many people enjoy having mosses as a background element of their garden, they are not usually cared for as specimens as we care for other gardened plants. One of the Arboretum’s current undertakings is to do just that – bring them to the forefront.
The goals in implementing moss plantings were to create areas that feature a diversity of moss species in the foreground, and help educate people about the common mosses of the Northeast. In the fall of last year, two small areas that exhibited favorable conditions for moss growth were selected as sites for moss gardens. So far we have identified and established 13 different species of moss in these small garden sites, many of which could be sourced from the large patches of moss growing in our Conservation Woodland. While they are off to a good start, only time will tell which species will survive our dry summer heat after the stress of the initial transplant.
This new addition is useful not only as a new design element, but also as an educational tool to help people learn about the diversity of moss species and determine which can be suitably and sustainably used in their own home gardens. As we continue to expand these moss gardens, we will investigate the effects of glyphosate on moss establishment, perform trials of different home-made moss propagation “milkshakes”, and gain a better understanding of the different characteristics of the various moss species found in this area. This project is not only a new initiative, but one that is completely different from anything we have done before. We hope you stop by to enjoy them.
Ferns
As an often overlooked foundational element of all Pennsylvania native woodland settings, ferns are the anchor for many plantings here at Jenkins Arboretum. It is little known that nestled far under the canopy of oaks and tulip poplars, Jenkins is home to over thirty different fern species, many of which are classified as Pennsylvania endangered species. Over the course of the next few months a dozen different species of ferns will be added to the Arboretum’s growing fern collection. Among these additions, five fern species are endangered in PA, including Climbing Fern (Lygodium palmatum) and Mountain Wood Fern (Dryopteris campyloptera), and we are excited to give them the space and protection they need to multiply and thrive. Another group of our new ferns, such as Walking Fern (Asplenium rhizophyllum) and Common Oak Fern (Gymnocarpium dryopteris), will be featured as mini-accents among the new moss plantings throughout the Arboretum. Finally, we hope to revitalize some of our established fern plantings by dividing and transplanting them to new and better locations that will highlight their differences and more accurately show their preferred natural setting. While this collection represents only a fraction of the ferns found growing wild in Pennsylvania, we are thrilled to add to our garden a broader level of conservation as well as further education for our visitors on the diversity of ferns found locally.
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