JARS v48n4 - ARS Seed Exchange: A Precious Resource

ARS Seed Exchange: A Precious Resource
Allan and Shirley Anderson
Franklin Lakes, New Jersey

One of the many services provided by the American Rhododendron Society is to make rhododendron and azalea seeds available in great abundance to members. More than 150 members from many countries contribute seed each year for distribution to ARS members via the Seed Exchange. An exhilarating variety of species, both hand pollinated and collected in the wild, are listed as well as hundreds of hand pollinated rhododendron and azalea crosses. This service is a remarkably well coordinated effort and a truly valuable resource.

Much of the seed available from the Seed Exchange is contributed by hybridizers who seek to produce new plants improved in some way over existing hybrids. It may be that a redder red with good dark foliage or a yellow well adapted to colder climates is desired. Perhaps a bicolor flower with contrasting dorsal flare would add variety or a plant that blooms earlier in the spring or later in the summer - or just a bigger flower and larger truss! Although new hybrids can sometimes be produced by selecting occasional mutations or inducing polyploidy chemically, the major source of new introductions is by means of hybridization. When it is realized that every seedling is a distinct and unique individual it becomes obvious that if new and different rhododendrons are to be introduced it must be through growing seed. No hybridizer can create colors or forms that don't already exist in the species, but he can reassemble characteristics in different combinations to create new rhododendron hybrids. It is in the nature of humans to desire what they don't have. This desire can be satisfied through cross-pollinating rhododendron hybrids and growing on the seed.

Earlier, pioneering hybridizers were handicapped by having to work with the limited number of species and hybrids available at the time. Many of their crosses produced primary hybrids which tend to yield fairly uniform populations. This resulted in progress that was somewhat slow. By building on the work of these early workers, however, a much larger group of very complex hybrids has been produced that carries the genetic material of many species. Crosses between such plants frequently produce extremely variable populations. It can be very exciting for the seed grower to wait for, and view the flowers from the seedlings of such divergent parents.

A beginning hybridizer may have limited access to the large number of plants and/or sources of pollen needed to make crosses. The Seed Exchange is a "made-to-order" source containing hundreds of crosses between an enormous variety of parents as well as a source for a wide range of species. No, all seed will not produce marvelous seedlings. Many will be poor, some may be awful, others may be lost along the way, but there will be a few gems that will please the fussiest rhodophile.

Our own interest in growing hybrid seedlings started in the early '70s when we first began ordering from the Seed Exchange, more out of curiosity than with any particular plan in mind. We made mistakes as will any beginner, but some of these early seedlings survived to bloom. Many died and still others produced buds that failed to open after severe Northeastern winters.

Gradually, as our interest in new seedlings became more intense, we began to develop specific objectives relating to the color, size and plant habit, and hardiness. We began to make crosses and began to contribute seed to the Seed Exchange. A few of the seedlings grown in our early attempts remain in the garden; others were used to move our hybridizing program forward and then discarded as more plants required more room. Our participation in the Seed Exchange program continues, as it is an important adjunct to our hybridizing program.

Several examples can be cited of plants grown from Seed Exchange seed that are pleasing additions to our garden. Seed Lot#807,1980 contributed by Jack Rosenthal. Parentage listed as ('Pink Twins' x R. yakushimanum 'Koichiro Wada') x ( R. aureum x R. yakushimanum ). The plant selected is small, well branched with elegantly presented pale pink to white trusses. It was a winner of the ARS Seed Exchange trophy at the Tappan Zee Chapter Truss Show.

In 1985 Jack Looye contributed seed lot#1363 identified as ('Sefton' x 'Purple Splendour') x ('America' x 'Mars'). Several of the plants produced good red trusses. One of the seedlings won the ARS Seed Exchange Trophy at the Tappan Zee Truss Show in 1993.

A favorite seedling came from lot #867 contributed by Dr. A. Fitzburgh to the 1981 Seed Exchange. The cross was ('Janet Blair' x R. strigillosum ). The seedling is now 5 feet in height, has dark green foliage, is well branched and showed no trace of winter damage after the 1994 winter in which we recorded a low temperature of -16°F. The flowers are a deep rose in color and well presented. The plant blooms at the end of April well before any other elepidote rhododendron in our garden. This plant will be named for Ellie Green, one of our granddaughters, and registered.

There are many other seedlings in our garden, bloomed and un-bloomed, including some that may one day be named, registered and introduced. Some of these are Seed Exchange plants and others are the result of our hybridizing for the last 10 years. The un-bloomed plants have a special fascination as they grow, first in observing the wide variety of plant habit and foliage, then as they form buds in the fall and we wait for spring to see the blooms. Each plant is an individual never before seen by human eyes. The "high" from watching these buds from fall through winter to spring is hard to exaggerate. Will they swell and bloom? What color will the flower be? What size? There are more disappointments than successes but when it happens - Wow!

Six thousand members of the American Rhododendron Society have diverse interests. Some want to use rhododendrons as a principal feature in their gardens so they are interested in culture, diseases and insect control. Others may wish to build a collection of the best and newest hybrids or species suitable to their climate. Still others are excited by tales of plant explorers looking for rhododendrons in the wild. Plant propagation by cuttings, grafts, and micro-propagation is another area of rhododendronitis to be explored. Many who become involved in the above interests sooner or later may become attracted to growing rhododendrons from seed. What better way to begin than an order from the ARS Seed Exchange, a passport to many pleasures in the garden.

Allan and Shirley Anderson are members of the Tappan Zee Chapter.