The Morris Arboretum of the University of Pennsylvania

In October of 2004 I had the great pleasure to attend the 57th annual meeting of the Holly Society of America where along with the Scott and Tyler Arboreta, the Morris Arboretum received a plaque recognizing us as an Official Holly Arboretum, an honor we have held since 1948. It was in that year, that we were recognized as one of the original holly arboreta along with: the New Jersey agricultural experiment station (Rutgers University), New Brunswick, NJ; Lowell Woods, Mashpee, MA; the Scott Arboretum, Swarthmore, PA; and the National Arboretum, Washington,DC. In the early years of the Holly Society, annual meetings were held twice yearly, with meetings held at the Morris Arboretum in 1949 and 1952.

Photograph 1: Group photograph taken at a Holly Society meeting held at the Morris Arboretum in 1949. (This photograph was taken in the Morris Mansion, which was unfortunately demolished in 1968.)

Although a few hollies remain from the Morrises' time, many plants have been added over succeeding decades and our collection is dispersed throughout the Arboretum. A large group of hollies was planted on our 'Holly Slope', from 1949-1953 on four acres of land the Arboretum acquired with our administration building, Gates Hall, in 1948. This slope was selected for its southern exposure and well-drained soils. Henry Skinner, the curator at the time, planted American hollies (I. opaca) at the more exposed top of the slope, and more tender species such as English and Altaclera holly (I. aquifolium and I. x altaclerensis) in the shaded and protected lower areas (photographs 2 and 5).


Photograph 2: A view from 1958 of young hollies planted on the Holly Slope at the Morris Arboretum.	Photograph 3: Holly Society members examining plants on the Holly Slope at the Morris Arboretum during the 1960 meeting.

Other meetings of the Holly Society were held at the Arboretum and photographs 2 and 3 show holly enthusiasts examining the collection in 1960 when the plants were between 10-15 years-old.

Currently we have 142 types of holly, including 117 evergreen and 25 deciduous taxa. Ours is one of the largest collections in the Delaware Valley, with many plants remaining from over 50 years ago. These older plants have grown to impressive sizes and Dr. Skinner would be proud to see his young plants reaching maturity today. Over the years the holly collection has gone through alternating periods of attention and benign neglect. In 1979 Susyn Andrews reviewed and verified parts of our collection, and a 1987 review of our collection updated our holly records and maps. Cold winters in the early and mid-1980s severely damaged some plants marginally hardy in our area such as Ilex aquifolium and I. cornuta; interestingly, a few years after being killed to the ground, some of these "de-accessioned" plants resprouted and were re-instated in our living records. During the 1980s and '90s numerous evergreen and deciduous hollies were added throughout the Arboretum as part of the general renewal of our collections and gardens. Many of these plants have thrived and are becoming a well-established part of our landscape. One of the most prominent holly plantings from this period is a large group of Ilex glabra 'Densa' used as a hedge to define the four quadrants of our Rose Garden.

I am often asked about the original specimens of Ilex 'John T. Morris' and 'Lydia Morris' and have to say that the originals were never here but came from the National Arboretum. These two selections are from a cross of I. cornuta 'Burfordii' and I. pernyi that Henry Skinner made in 1948 while at the Morris, but the parent plants are unknown. Subsequently he took plants with him to the National Arboretum, and named these two cultivars in 1961. Our plants are from 1963 and are derived form the original ones at the National Arboretum, where the original 'John T. Morris' is still alive although the original plant of 'Lydia Morris' died in 1990.

Since I became curator of the Arboretum in 1999 I have undertaken a long-term project of renovating our holly collection by verifying, pruning, planting, and removing plants. Goals of our holly renovation project are to: improve the health and beauty of our existing plants by removing unidentified or unhealthy specimens; grow wild-collected species and propagate superior varieties from other collections; add diversity to our holly collection by planting newer and better-performing hollies; serve as a conduit for sharing hollies with individuals and other botanic gardens; and ultimately demonstrate a wider range of hollies to the gardening public (Photograph 6).

In 2002 Carla Hetzel (currently at the Tyler Arboretum) performed a thorough evaluation of the collection, making recommendations for propagating, pruning, and removing plants throughout the Holly Slope.

Since this evaluation we have continued systematic, bed-by-bed renovations of the holly collection, working to rejuvenate this important but crowded group of plants. As space has opened we have selectively added new plants to the Holly Slope and integrated more hollies throughout the rest of the Arboretum. Some of the highlights of plantings in recent years include Ilex x wandoensis, I. yunnanensis, I. x koehneana 'Wirt L. Winn' and Yule Brite™ , I. 'Edward J. Stevens' and 'Emily Bruner' (Photograph 7), and I. latifolia. Clearing out beds and overgrown plants also leads to unexpected views and sheds new light on old plants. One of the most outstanding old hollies uncovered by our renovations is I. opaca 'Freeman', which came to us in 1949 (Photograph 7). This 50+ year-old plant is 15 feet wide by 60 feet tall and draws the attention of all visitors interested in plants and especially those interested in hollies. It is a superb American holly, one that would be an excellent addition to any nursery's inventory and to any garden. Located at the base of the Holly Slope, our Oak Allee serves as an excellent location for building our collection of deciduous hollies, primarily a number of cultivars of Ilex verticillata, including my current favorite 'Sunset'. Also planted in this area are the deciduous hybrid cultivars including I. 'Autumn Glow' and 'Harvest Red' and some less common species such as I. laevigata, the smooth winterberry of the eastern United States. Deciduous hollies perform much better than most other plants in the wet soils of the Allee, and its expansive beds allow for mass plantings that give excellent winter displays.

Beginning in 2001 we have been targeting holly cultivars for propagation, adding taxa that are not well represented in our collection. Each fall we visit Rutgers University Gardens or the Scott Arboretum, focusing our propagation efforts on varieties of Ilex x altaclerensis, I. x koehneana, I. aquifolium, and a few other select plants such as I. latifolia. Our efforts have paid off and we currently have some wonderful young hollies making their way through our greenhouses, and reaching a size that can be planted throughout our gardens. I have a particular fondness for Koehne hollies, and so it is especially gratifying to see how well these are coming along. Also among my personal favorites are two very similar plants, I. aquifolium 'Angustifolium' and 'Petite'. For two years and we have taken cuttings from beautiful specimens at the Scott Arboretum and I look forward to having these grace the Morris Arboretum (not to mention my home garden). An offshoot of our holly propagation is that we always have extra plants on hand, and frequently share them with visitors from other botanical institutions. Because of a close relationship with Chanticleer, last year we helped them build their holly collection by providing 31 plants of 16 types, including Ilex aquifolium 'Virginia Nosal', I. opaca 'Orlando Pride', I. pedunculosa, four cultivars of I. x altaclerensis and three cultivars of I. x koehneana. So, not only are we working to improve our collection, but we are spreading the holly 'gospel' to many of our horticultural friends.

In addition to vegetative propagation, we have focused on growing some less common holly species acquired through seed exchanges and on plant collecting trips in the U.S. and Asia. Our goal is to have broad representation of documented and wild-collected species of Asian and North American origin. As with I. yunnanensis mentioned above, many of these are planted but we still have others such as I. fargesii, I. shennongjiaensis, I. ambigua, I. macropoda, and I. colchica (seed collected in the Republic of Georgia) in our greenhouses.

Photograph 7: Morris Arboretum Holly Slope in 2004
with Ilex 'Emily Bruner' (MA#96-003*A) in the foreground and
I. opaca 'Freeman' (MA#49-425*B) in the midground right,
with its crown about the horizon line.

Renovation of our holly collection is a long-term project , one which will keep me happily engaged for many years (although I sometimes wonder about the rest of my staff). Over the coming few years we will continue renovations and removals, identify unique cultivars for propagation and distribution, grow-on and plant newly propagated cultivars, and identify and propagate deciduous holly varieties not currently in the collection. It is a great pleasure getting to know and work with members of the Holly Society; being well-aware of the long association between the Society and the Morris Arboretum, I look forward to maintaining and strengthening our relationship. As I write this from my office, a soft snow is falling onto our holly collection, and I cannot help but think how fortunate I am that can observe and enjoy the these wonderful plants throughout the seasons. If any members are ever in the area, please stop by and we can enjoy sharing some time among our hollies!

Ilex opaca 'Old Heavy Berry,' an exceptionally
heavy fruiting clone of American Holly.

Hollies have separate male and female plants, so unless male plants are known to be in your neighborhood, you will have to plant both sexes to get good fruit-set. With so many beautiful varieties of holly it is difficult to recommend just a few, however here are a few suggestions to get you started:

So if you are looking for a little touch of green this winter, come to the Arboretum and enjoy our Holly Slope. Hopefully you will be inspired to grow some of these wonderful plants in your own garden.