JARS v48n3 - The Mehlquist Garden: Rhododendron Revival at the Bartlett Arboretum

The Mehlquist Garden: Rhododendron Revival at the Bartlett Arboretum
Mike Rachinsky
Stamford, Connecticut

A 28-Year-Old Collection
The collection of rhododendrons and azaleas at the Bartlett Arboretum is part of a larger collection of plants in the Ericaceae family including mountain laurel, leucothoe, heaths and heathers, hollies and pieris. The first rhododendrons and azaleas were planted in 1966 and 1967 by Dr. Gustav Mehlquist in what is now the Mehlquist Garden. His well known plant breeding program at the University of Connecticut provided many of the specimens for the newly acquired arboretum in Stamford. At that time a rough map was drawn and an inventory list was developed. However, by 1988 the area was in need of renovation and the inventory needed updating. Mike Rachinsky along with other volunteers and arboretum staff began re-identifying plants and redrawing the maps. Paths were cleared and trees were pruned. In 1990 the Mehlquist Garden was dedicated to Dr. Mehlquist whose lifelong breeding program yielded many of the plants described here in Mike Rachinsky's article.

About 25 years ago Dr. Gustav. A. L. Mehlquist planted numerous hardy rhododendrons and azaleas in an area of the University of Connecticut's Bartlett Arboretum in Stamford. In 1990 the area, which measures over an acre, was dedicated in honor of Dr. Mehlquist and became the Mehlquist Garden.
Dr. Mehlquist's career as a horticulturist spans over a period of 70 years. He has been involved with the breeding of rhododendrons since 1958. At present he is a Professor Emeritus of the University of Connecticut and also the owner of Gem Gardens in Storrs, Conn.

Dr. Gustav Mehlquist with R. 'April White
Dr. Gustav Mehlquist with 'April White'.
Photo courtesy of Dr. Mehlquist

We are able to speak of the existing Mehlquist Garden as involving two stages. The first stage began in 1966-1967 when the initial plantings took place. The rhododendrons in this stage of planting are now mature ranging in height from three to 10 plus feet. The second and continuing stage consists of the revival and further diversification of the garden. Reference to this second stage was briefly noted in the summer 1992 ARS Journal (Vol. 46, No. 3). Identification, pruning, and removal of some plants has been and is being performed. Accompanying these actions is the total amelioration of the garden paths. Excessive overgrown shade trees are being pruned and removed gratis by the Bartlett Tree Expert Company. (The arboretum land was originally owned by Frances A. Bartlett, founder of the F. A. Bartlett Tree Expert Company. The Bartlett family still owns the tree company.) Newer plantings of Dr. Mehlquist's creations with other breeder's hybrids and species has occurred and continues to take place.
These healthy, mature rhododendrons and azaleas have flourished with little or no care for the past 25 years. Obviously these plants are all "good doer's" for this USDA Zone 6 in southwestern Connecticut.
Among these plants are many hardy Rhododendron catawbiense , R. minus Carolinianum Group, and R. fortunei seedlings. Both white and pink forms of R. minus Carolinianum Group are present. Among the fragrant R. fortunei are the very desirable cream-yellow colored cultivars. To name just a few of the existing garden plants, there are the Joseph Gable rhododendron hybrids 'Caroline', 'Disca', 'Cadis', 'County of York'*, 'Katherine Dalton', and the lepidote 'Gable's Pioneer'; Guy Nearing's 'Windbeam', and 'Ramapo'; Anthony Shammarello's 'Besse Howells', 'The General', 'King Tut', 'Cheer' and 'Lavender Queen'**; David Leach's 'Vernus' and 'Mist Maiden'; Charles Dexter's 'Betty Hume', 'Warwick'**, 'Ben Moseley', and 'Scintillation' AE; and the European hybrids 'Blue Peter', 'America', 'Nova Zembla', 'Chionoides', 'Madame Masson', 'Roseum Elegans', 'Boule de Neige', and 'Catawbiense Album'.
This earlier planting also includes some hybrid and species evergreen and deciduous azaleas as well as other species rhododendrons. Dr. Mehlquist planted a few of his earlier unnamed hybrids. Among these are one or two beautiful coral colored Rhododendron 'Vulcan' x R. fortunei crosses.
For the present planting, Dr. Mehlquist's hybrids and species are being added with creations of Joseph Gable, David Leach, Weldon Delp, Tom Ring, Orlando Pride, Harold Greer, Dietrich Hobbie, Russ and Velma Haag, and William Rhein among others.
Among Dr. Mehlquist's hybrids are his April blooming Rhododendron dauricum crosses. These R. dauricum hybrids are low and dense growing, reaching about three to four feet in 10 years. 'April Dawn', growing to about four feet, is a cross of the white flowered form of R. minus Carolinianum Group and R. dauricum . It blooms with white flowers with a blush of light pink.

R. 'April Rose
'April Rose'.
Photo courtesy of Gustav Mehlquist

'White Surprise' is another interspecific cross. This hybrid contains the white forms of R. dauricum and R. mucronulatum . The more complex crosses of the April series include 'April Gem', 'April Reign', 'April Rose' and 'April White'. Their parentage includes R. dauricum , R. mucronulatum , and R. minus Carolinianum Group.
'April Gem' is a fine double-flowering white. 'April Reign' is a beautiful pink semi-double form. It has mahogany colored leaves in winter. 'April Rose' has abundant bright magenta double flowers with bronze winter foliage. 'April White' has numerous long-lasting semi-double white blooms.

R. 'Firestorm'
Photo by Mark Brand

A number of elepidotes have also been introduced by Dr. Mehlquist. Of these are the true red 'Firestorm' and 'Scarlet Romance'.** Their seed parent is 'Vulcan' and they are hardy to -25°F. 'White Peter' is a selfed form of 'Blue Peter' with striking white flowers flared with dark purple to black. It is less heat sensitive than its parent and also hardy to -25°F. Rhododendron 'Wojnar's Purple', coming from the efforts of the late John Wojner, has dark purple flowers with a black flare. It is hardy to at least -20°F.

R. 'White Peter'
'White Peter'
Photo by Mark Brand

Rhododendron 'Connecticut Yankee' with bluish-purple flowers is extremely floriferous, blooming in mid-June and is hardy to -25°F. Also to be found are the interspecific crosses of Rhododendron yakushimanum and R. smirnowii . Of these are 'Dorothy Swift'** and 'Today and Tomorrow'.** Both parents and the progeny bear a beautiful wooly indumentum and are excellent foliage plants. The flowers are pink in bud and fade to white when open.
There is a planting of the cross of 'Scintillation' AE and the species R. williamsianum at the entrance of the arboretum. This hybrid has fine R. williamsianum type foliage.
Dr. Mehlquist's hybrids are already being released in the trade. Gem Gardens and other gardens will be a further source of plants for the Mehlquist Garden as well as for the growers of hardy plants.

Dr. Michael Rachinsky, a member of the Tappan Zee Chapter, recently passed away. He voluntarily helped map and identify hundreds of rhododendrons and azaleas at the Mehlquist Garden at the Bartlett Arboretum over a period of four years, beginning in 1988.

Editor's Notes: * The registered name is 'Catalode' although it is known by most as 'County of York'. ** Name is not registered.