JARS 43n1 - The Children Of 'R. O. Delp'

The Children Of 'R. O. Delp'
Homer Salley
Grand Rapids, Ohio

Weldon and Ginny Delp's location in central western Pennsylvania has a harsh climate for rhododendrons, though some native species survive there. Winters are extremely cold, at times with little snow cover, and temperatures as low as -25F. Outside growing seasons last about three months, enough for only one full flush of new growth. Late frosts often cut back fully opened trusses in the spring and by mid-September there could be a freeze. Young seedlings must be protected in unheated poly houses. Those with their first flower buds are watched carefully and moved to heated greenhouses in time for opening in late April to mid-May.
Is it the fragrance that sends an alert to the many who make an annual pilgrimage to the Delp's garden in Harrisville, four miles east of the Grove City College campus? Bees collect pollen; so do hybridizers. Some come to take photos for the news media. A few may get to take home discarded seedlings. Most come just for the excitement of seeing new rhododendron hybrids as they first appear, another miracle of birth. Some say they get a "rhododendron education"! In return, many make donations to the Crystalaire Rhododendron Foundation.
It would take many pages to tell of Weldon's forty years' work as a hybridizer. But we can tell a short story about a small part of his recent work. To tell this story about rhododendron hybrids and their creators we must first identify those who have played significant roles. Some of the people have the same names as the plants. 'R. O. Delp', appropriately named after Weldon's father, is the real hero of this story, being the seed parent of all the children shown here in color and honored with their complete published genealogies.

R. 'Sting-Ray'
Photo by Weldon Delp

Another hybrid published elsewhere is 'Christina Delp' ('Catalgla' x 'Mrs. W.C. Slocock'), named for Weldon's late mother. As an untiring greenhouse assistant she got bored one day writing out plant labels with ('Pygmalion' x haematodes ) x yakushimanum , Exbury form. So she named the plant 'Weldy', not just because it is one of his best but to save her a lot of time! Not many selections had been named before that, but many more were named afterwards with the advent of the computer.
'Anna Delp' ('America' x 'Blaze'), and 'Anna Almeda' ('Ben Moseley' x 'Dusty Maid'), are named for Weldon's sister to honor the only other child of R. O. Delp and Christina. The most frequently honored of all in the family is Virginia, Weldon's wife: 'Ginny Delp', 'Ginny's Delight', 'Ginny Mae', and 'Virginia Delp'. (The last named is not a Delp creation, but an Al Smith hybrid.)

R. 'Charlie G.'
'Charlie G.'
Photo by Homer Salley
R. 'Tight End'
'Tight End'
Photo by Homer Salley

In the early spring Weldon works long days and sleeps short nights. At first crack of dawn he sprinkles young budded plants and looks for flowers of such beauty as he had never seen before, the hybridizer's reward for all his previous years labors. One day will there be a rich, golden yellow with the hardiness of an oak? Which yellow is so hardy? To find that answer, commercial introducers must propagate and distribute widely to growers and collectors. A few nursery catalogs list some Delp hybrids by name. Cardinal Nursery is his chief introducer, but demand exceeds supply at present so scarce items may go unlisted. Offers are declined from micro-propagators who expect exclusive rights.

R. 'Regal Crown' R. 'Well-Suited'
'Regal Crown'
Photo by Weldon Delp
Photo by Weldon Delp

Ginny's role is to "color" them and name them. To "color" them is to use the RHS Colour Chart for exact identification by chart number. In 1988 the spring crop produced some 86 named selections added to the computer's data bank. A total printout now runs to 60 pages, 10-12 descriptions per page! When asked for names of some she considers the better plants, the author ran out of space before she ran out of names: 'Sweet Lulu', 'Katydid', 'Tutu Lou', 'Heap Big Indian', 'No Wonder', 'Opalescence', 'Holy Toledo!', 'Fiery Orange', Tickled Pink', 'Jelly Bean Fever', 'Cosh Darn!', 'Sharpie', 'Frizzy Liz', 'Gee Whiz!', 'Classy Lassie', 'Jeepers Creepers', 'Spin-off', 'Yellow Streaker', 'Masterblend'.

R. 'R. O. Delp'
'R. O. Delp'
Photo by Homer Salley

Hundreds of hybrids and species have been tried as parents. A few have been found to be promising. 'Catalgla' - catawbiense var. album Glass is a sure thing for hardiness. 'Oh My' ( smirnowii x yakushimanum ) has often been a seed parent or a pollen parent. But the most prolific breeder is 'R. O. Delp' ('Lodestar' x 'Mary Belle'). This cross was made in 1974 by Weldon and Dr. D.L. Hinerman at Ann Arbor, Michigan. When the computer is asked for all the children of 'R. O. Delp' the search produces 29 names and descriptions, as seed parent only. As pollen parent another long list would be forthcoming.
'R. O. Delp' is illustrated here in color and the complete parentage is shown in the following diagrams. It carries ample genes for hardiness transmission, and does not seem to tend toward female dominance in color traits. Colors from the male pollen plant usually are revealed in the offspring of 'R. O. Delp' and its mates. Weldon thinks the golden yellow in 'Liquid Gold' came from 'Golden Star' and one parent of 'R. O. Delp', 'Mary Belle'. That blotch in 'Charlie G.' could have come from 'Lodestar', 'Harvest Moon', 'Ice Cube',- any one or two or all three of them!


R. 'R. O. Delp' parentage

Body Language : Buds strong to moderate purplish red open to flowers deep to light purplish pink, dorsal spots brilliant green.
Charlie G. : See color illustration.
Purity : Buds deep to strong purplish red open to pale yellow flowers, dorsal spots strong purplish red.
Tight End :See color illustration.

Delp hybrid parentage

Dusty Whiz : Buds dark pink open to orange flowers, edged red.
Liquid Gold : See color illustration. (located on index page)
Regal Crown : See color illustration.
Stardust : Buds brilliant greenish yellow open to pale greenish yellow flowers, moderate orange dorsal spots.

Delp hybrid parentage

Checkmate : Buds moderate purplish red, open to flowers light to pale purplish pink, dorsal spots moderate purplish red.
Freckle Face : Buds vivid red to moderate purplish red, open to reddish purple, reverse veined deep purplish pink.
Pink Carousel : Buds strong purplish red, open to flowers strong to light purplish pink.
Pure Elegance : Flowers deep to moderate purplish pink, blotch light yellow.
Sting-Ray : See color illustration.
Top Dog : Buds deep to strong purplish red, open to flowers very pale purple, dorsal spots deep purplish red.

Delp hybrid parentage

Pacesetter : Buds a blend of brilliant to light greenish yellow, open to light greenish yellow flowers.
Peach Delight : Buds strong purplish red to light purplish pink, open to flowers yellowish white, edged red.
Well-Suited : See color illustration.

The other children of 'R.O. Delp' are described below with their parentage but without their entire family tree:

R.O. Delp x Lifeline

Lifeline = (brachycarpum x Crest) x Cindy Lou
Inner Spirit Light to pale purplish pink buds open to pale purplish pink flowers.
Pizzazz Deep purplish red buds open to deep purplish pink, moderate red spots.
Remote Control Strong purplish red to deep purplish pink buds open to purplish pink, dorsal spots deep red.
You Betcha! Buds moderate reddish orange open to pale greenish yellow flowers.
R.O. Delp x Lanny Pride Power Base Strong purplish red buds to flowers strong purplish red and light pink.
Tipster Buds strong purplish red open to reddish purple flowers.
Whimzee Flowers strong purplish pink.
R.O. Delp x (Weldy x Serendipity) Heart Talk Moderate to strong purplish red buds open to pale purplish pink.
Santa's Whiskers White flowers, stigma strong reddish orange.
R.O. Delp x (brachycarpum x Crest) x
(Mars x America)
Free Reign Yellowish white, edged brilliant yellow green & deep purplish pink.
Topper Buds deep, dark red, open to strong purplish red and pink.
R.O. Delp x (Mary Belle x Powell Glass) It's Special Flowers white, lightly edged strong purplish red and pink.

Laing, John, 'Rhody' Romance Relished 40 Years; Butler Eagle (Butler, PA) June 6, 1986.
Huse, R.D., and K.L. Kelly, A Contribution Toward Standardization of Color Names in Horticulture , American Rhododendron Society, Portland, OR, 1984.
Royal Horticultural Society Colour Chart; The Society, Vincent Square, London, 1966.
Salley, H.E., and Greer, H.E., Rhododendron Hybrids: A Guide to Their Origins ; Timber Press, 1986, p. 375.

Homer Salley, co-author of Rhododendron Hybrids: A Guide to Their Origins, is a long-time friend and admirer of Weldon Delp's hybridizing work.