For Dr. Stephen Krebs, Christmas comes in May.

That is when the thousands of rhododendrons at the David G. Leach Research Station put forth the blossoms that reveal the success of his work.

“This is the fun part,” said Krebs as he walked the rows of rhododendrons planted in the research station’s field. “It’s like Christmas to come out here and see these buds open.”

The 30-acre research station is located in a Madison Township residential neighborhood near Lake Erie. It is owned by the Holden Arboretum, but with the exception of special spring tours, is closed to the public. Tours are scheduled for this weekend by advance reservation only (see sidebar).

Holden acquired the research station by donation in 1987. Its namesake, David Leach, started the work in Madison in 1970, after a fire at his property in Brookville, Pa., destroyed most of his prior work. Leach, who was in his late 50s at the time, relocated about 6,000 surviving plants to the property, including some that weighed hundreds of pounds.

Leach’s reputation as an expert rhododendron breeder was well established in the world by the time relocated to Madison and built a house and gardens on what was formerly a truck farm. He had made his money running the family’s glove factory and at the age of 40, left the business to pursue his passion, a study of the genus Rhododendron.

Leach traveled extensively to meet the world’s best rhododendron breeders and visit collections. In 1961, Leach’s landmark classic, “Rhododendrons of the World,” was published. He held two doctor of sciences degrees and received six gold medals for his work, which was recognized worldwide.

Leach also found time to work as a professional photographer, working for both Life and National Geographic.

Krebs, who worked with Leach from 1992 until Leach’s death in 1998, sums up his mentor’s personality as a man who insisted upon eating dessert first. Not surprisingly, he approached his rhododendron with equal zest.

East meets West

Worldwide, there are nearly 1,000 species of rhododendron in the wild, most of them in Asia. Their blossoms range in color from white to the deepest red; their form from nearly 100 feet tall to low growing and compact. Foliage ranges from broad to narrow leaves with various colorations.

Leach’s passion was introducing this array of characteristics to the hardiness of the North American Rhododendron catawbiense and R. maximum species, resulting in rhododendrons hardy to zone 5. Leach’s work thus made it possible for gardeners in colder climates to enjoy the range of Asian rhododendron colors, sizes, structures and blooming times.

Although Leach hand pollinated these parents tens of thousands of times, relatively few cultivars met his stringent standards. Only 80 to 90 of his best hybrids went into commercial production. Some of the well-known ones are Arabia, Bikini Island, Bravo!, Capistrano, Catalina, Golden Gala, Nepal, Persia and Samoa.

“I think his main feeling was that he was very particular,” says Krebs. “A lot of breeders name thousands of plants. In 50 years he named less than 100. It shows his standards were very high.”