The Weston Nurseries Rhododendron and Azalea Hybrids
R. Wayne Mezitt
Soon after earning his Architecture degree at Cornell in 1937, Ed Mezitt recognized that, compared to other parts of the world, the plant choices for landscaping in New England were sorely lacking. For years he and his dad, Peter J. Mezitt, had grown a number of crops from seed at the nursery in Weston. They had often selected superior seedlings from nursery populations to vegetatively propagate so that they could offer their customers better clones of common varieties.
With the arrival of a new rhododendron from China1, my dad recognized an opportunity to introduce a new genetic line into plants. His first attempt at hybridizing in 1939 turned out to be unbelievably fortuitous, resulting in the now world-famous 'PJM' Hybrids.
Buoyed by his success with 'PJM', my dad continued his hybridizing work, which he typically referred to as "pollen dabbing." As I joined with him and became involved, his "mental" criteria focused on expanding the season of bloom, increasing hardiness and adaptability, and adding year-round appeal in the new hybrids.
We are indeed fortunate to have good records of his crosses. His first written records are from 1951 and 1958. It's obvious to me that the habit of keeping accurate records developed concurrently with the work he began with Dr. Robert Tichnor2. From 1963 onward we have a complete record of all the crosses that produced seed. There are a total of over 4,500 crosses that actually produced seedpods!
I began working with my dad in 1966 and participated in many of his exciting discoveries. We defined and refined his initial informal selection expectations to add other criteria like good foliage, compact growth habit, pest resistance, and fragrance, particularly for the Summer Azaleas.
Over the years some of the Weston hybrids have set a higher standard for these criteria. Often the results turned out to be extremely fortunate, though unintended. For example, the extreme hardiness of many of the lepidote hybrids, their sun tolerance, occasional tendency to be petaloid, and their aromatic foliage were all unexpected.
Several years ago Jay Murray3 strongly encouraged me to register more of the Weston Nurseries hybrids with the Royal Horticultural Society. As you see by the "R" symbol, Jay was successful in getting us to do this for many of the important hybrids. This has sometimes required name changes, and that's why so many names start with 'Weston's'. We still have a number more to register and intend to complete the list in 2002.
Sadly, some of these hybrids are now lost, no longer to be found in Hopkinton, and these "lost" ones are so indicated. If perchance you know of any true plants of these, we would very much appreciate the opportunity to root some cuttings and return them to our gene pool for future generations.
I hope you enjoy looking over the parentage of these hybrids. Perhaps they will form a basis for further improvements in the choices available for landscaping in this region.
We start the list with the lepidote group in this issue of The Rosebay and will continue with the elepidotes, deciduous azaleas, and evergreen azaleas in subsequent issues.
1 See "The Origin of Rhododendron PJM." by Edmund V. Mezitt, The Rosebay, vol. 1:1, p. 1, February 1972. Reprinted in this issue, page 9.
2 Then affiliated with the Cooperative Extension Service, University of Massachusetts Field Station, Waltham, MA.
3 Mrs. Jay W. Murray, ARS Registrar of Plant Names.
Editor's note: For further reading in The Rosebay about Weston Nurseries, see R. Wayne Mezitt. "How We Developed Double-flowering Lepidote Rhododendrons at Weston Nurseries". Fall 1992. v.20:2, p. 3.; and Bruno Falanga, ed. "A History of Weston Nurseries" as presented by Edmund V. Mezitt in 1985. Fall 1988. v. 17:2., p. 1. See also A. Richard Brooks. "The Weston Hybrids". JARS (Fall 1999), v. 53:4, p. 195. This last article is available on the Web at www.rhododendron.org.
Checklist of Hybrid Lepidote (Small Leaf) Rhododendrons
Introduced by Weston Nurseries With Parentage
Compiled by Wayne Mezitt
Updated December 28, 2001
Many cultivars are no longer in production.
All numbered hybrids are Weston Nurseries crosses.
Underline denotes flowering with or earlier than Rhododendron 'PJM'.
(Parentage, when known, shown in parentheses).
"R" signifies cultivar is registered by the Royal Horticultural Society, which serves as the International Registration Authority for the genus Rhododendron.
"LOST" signifies the cultivar is no longer found in Hopkinton.
April Cloud. Petaloid white with rounded petals. 1978 cross 78-184-1. (73-107 x 'Laurie'). R
April Glory. Petaloid purple flowers, mahogany winter foliage. 1978 cross 78-184-5. (73-107 x 'Laurie').
April Joy. Very early flowering petaloid pink, slow growing. 1978 cross 78-175-2. [73-107 x ('Gable's Pioneer' x PJM Group)]. R
April Love. Petaloid pink. 1978 cross 78-175-8. [73-107 x ('Gable's Pioneer' x PJM Group)]. R
April Ruby. Dark pink flowers, dark mahogany winter foliage. 1977 cross 77-103 (or 77-107?). ('Black Satin' open pollinated).
April Snow. Petaloid white with pointed petals. Compact. Yellow winter stems. 1978 cross 78-184-3. (73-107 x Laurie'). R
April Song. Petaloid pink with lighter inner petals. 1978 cross 78-175-9. [73-107 x ('Gable's Pioneer' x PJM Group)]. R
Balta. Near-white with pale pink buds, compact growing. 1958 cross 33. (minus Carolinianum Group, white x PJM Group). R
Black Satin. Lavender-pink flowers, foliage black-mahogany in winter. Selected ~ 1975. (PJM second generation seedling). R
Blue Baron. Dark purple-blue, compact growing. 1981 cross 81-116. ['Starry Night' ('Gletschernacht') x 'Waltham']. R
Blue '81 Hybrid. Dark purple-blue flowers, compact growing. All characteristics are similar to 'Blue Baron', but parentage is different. 1981 cross 81-117. ['Starry Night' ('Gletschernacht') x 3rd generation 'PJM' seedling].
Caronella (originally 'Shrimp Pink #1'). Pink with darker petal edges. 1958 cross 36. (minus Carolinianum Group, white x mucronulatum 'Cornell Pink'). R
Checkmate (PJM Checkmate). Compact-growing, lavender-pink flowers, dark mahogany winter foliage. c. 1987 tissue culture origin. (Tissue cultured propagule of 'PJM Victor'). R
Counterpoint. Petaloid pink. 1972 cross 808. [('PJM' x pink mucronulatum) self-pollinated].
Desmit. Compact growing, light pink flowers. c. 1958 cross by Robert Tichnor, selection # 10. ('Laetivirens' x minus Carolinianum Group). R, LOST
June Pink. Clear bright pink. Slow growing. 1977 cross 77-44. ('Olga Mezitt' second generation selection). R
Landmark. Dark pink flowers, leathery foliage turns bronzy in winter. 1985 cross 85-281. ('Counterpoint' x 'Carolina Rose'). R
Laurie. Near white flowers, pinkish buds, compact growing, foliage coppery in winter. 1958 cross 33. (minus Carolinianum Group x PJM Group). R
Lavender Frost. Petaloid lavender with yellowish center. 1977 cross 77-152. ('Laurie' x dauricum white. R
Legacy.Petaloid purple, dark mahogany winter foliage. 1982 cross 82-78. ('April Glory' x 'Princess Susan'). R
Little Olga. Pink. Sport of 'Olga Mezitt'. Selected by Ed Mezitt before 1984 as a unique individual from plantings of 'Olga Mezitt' growing in the open field. R
Llenroc (Originally 'Shrimp Pink #3'). Pale pink with yellowish center. Slowest growing of the Shrimp Pink series. 1958 cross 36. (minus Carolinianum Group, white x mucronulatum 'Cornell Pink'). R
Lucy. Compact growing lavender-pink. 1972 cross 866. [(minus Carolinianum Group x myrtifolium) x dauricum Sempervirens Group].
Lynne Robbins Steinman. Petaloid pink. Named in 1990. 1978 cross 78-186. (cross 73-107 open pollinated).
Midnight Ruby. Red-purple, compact growing; black-bronze winter foliage. 1973 cross 73-108. ('Olga' x PJM Group). R
Milestone. Early bright pink. Compact growing. Winter foliage is retained about 10% and turns bronze-mahogany. 1972 cross 913. (minus Carolinianum Group x dauricum Sempervirens Group) selfed. R
Molly Fordham. Near white. 1966 cross 430. ('Balta' x minus Carolinianum Group). R
Mrs. Jeremiah Aloysius Withington III (registered as Mrs. J. A. Withington III). Petaloid light lavender. 1977 cross 77-152. ('Laurie' x dauricum Sempervirens Group, white). R
Nancy Paxton. Clear pink flowers with a coppery flare. 1975 cross 75-40. (2nd generation 'Vallya' seedling).
New Patriot. Dark pink. 1979 cross 79-262. ('Staccato' open pollinated). R
Olga Mezitt. Pink flowers, coppery-bronze winter foliage. 1964 cross 226. (minus compact selection x dauricum hybrid, pink flowered). R
Peach Blend. Very early pale pink. 1964 cross 204. (mucronulatum 'Cornell Pink' x keiskei).
Pillar. Early, brilliant lavender pink flowers on an upright-growing plant. Selected in the 1970s. (minus Carolinianum Group x dauricum Sempervirens Group).
PJM Group. Early, brilliant lavender pink flowers cover the plant in April. Fragrant bright green foliage turns dark mahogany in winter. This was Ed Mezitt's first attempt at hybridizing in 1939. (minus Carolinianum Group x dauricum Sempervirens Group). R
PJM clones: PJM Elite, PJM Regal and PJM Victor. Early, brilliant lavender pink flowers cover the plants in April. Fragrant bright green foliage turns dark mahogany in winter. Superior selections made in the 1960s from the 1939 'PJM' grex. (minus Carolinianum Group x dauricum Sempervirens Group).
PJM Elite. Bright lavender-pink flowers Latest of all PJM selections to bloom, 3 to 5 days after 'PJM Victor'. Vigorous, wide, upright growing. R
PJM Regal. Strong lavender-pink flowers, blooming after 'PJM Victor' and slightly before 'PJM Elite'. Wide, upright, and a bit slower growing than 'PJM Elite'. R
PJM Victor. Lavender-pink flowers bloom up to 2 days before the other clones. Rounded, glossy green leaves somewhat smaller than other PJM clones, and tend to develop winter color earlier. Compact, broad and upright. R
Princess Susan. Lavender-pink flowers, compact growing, black-mahogany winter foliage. 1972 cross 827. ['Balta' x (minus Carolinianum Group, white x PJM Group)] selfed.R, LOST
Red Quest. Dark red flowers, compact. 1979 cross 79-351. ('Waltham' x dauricum Sempervirens Group, pink). R
Red Splash (originally 'Splash'). Dark red flowers, compact. 1979 cross 79-351. ('Waltham' x dauricum Sempervirens Group, pink). R
Sidestep. Pale pink buds open to white flowers in May. Compact growing. Bronze-green winter foliage. Selected ~ 1978. ('Waltham' seedling selection). R
Staccato. Petaloid pink. Semi evergreen foliage turns bronze-mahogany in winter. 1972 cross 949. [('PJM' x mucronulatum pink) selfed].
Thunder. Early dark purple; black-mahogany winter foliage. 1971 cross 653. ('PJM' second generation seedling). R
Unnamed cross 73-107. Petaloid lavender flowering selection from a 1973 cross. Used as parent for many crosses. (PJM Group, double flowered x mucronulatum, pink) x dauricum Sempervirens Group, white).
Vallya (Wally) (originally 'Shrimp Pink #2'). Pale pink. 1958 cross 36. Named by Ed Mezitt in the 1960s for his wife. (minus Carolinianum Group, white x mucronulatum 'Cornell Pink'). R
Waltham. Small pink flowers late in season, low and compact. c. 1958 cross by Robert Tichnor, selection 11. ('Laetivirens' x minus Carolinianum Group). R
Weston's Aglo (originally 'Aglo'). Pink with coppery eye, coppery-green winter foliage. 1964 cross 226. (minus compact selection x dauricum hybrid, pink). R
Weston's Crescendo (originally 'Crescendo'). Pale pink, maturing darker; large foliage, compact. 1975 cross 75-3. (PJM Group, semi-double x minus Carolinianum Group, pale pink) F2. R
Weston's Mayflower. Late flowering pink, compact and low. 1971 cross 609. [('Laetivirens' x minus Carolinianum Group) x (minus Carolinianum Group, pink x myrtifolium)]. R
Weston's Pink Diamond. Very early petaloid pink. Winter foliage is retained about 10% and changes to bronze-mahogany. 1964 cross 201. ('PJM' x mucronulatum 'Cornell Pink'). R
Weston's Starburst. Early petaloid pale lavender. 1977 cross 77-152. ('Laurie' x dauricum white). R
White Angel. Lavender-pink buds, near-white flowers. 1973 cross 73-92. (minus Carolinianum Group, white x dauricum Sempervirens Group, white).
"Shrimp Pink Hybrids"
For many years the Weston Nurseries' catalog carried a listing for "Shrimp Pink Hybrids", a group of only three selections made from Ed Mezitt's 1958 cross 36, R. minus Carolinianum Group, white x R. mucronulatum 'Cornell Pink'. Today they are named, registered, and listed as: 'Caronella, 'Llenroc', and 'Vallya'.