You don’t need a Ph.D. in microbiology to crossbreed your favorite flowers, but it sure doesn’t hurt to have a basic understating of plant science.

So says Henry Bradford, who does hold such a Ph.D. and took up hybridizing daylilies with his wife, Patty, about 10 years ago.

“Before then, I was interested in camellias, and we have about 300 bushes on our land,” Bradford said. “But I got hooked on daylilies when our good friends, Elaine and Jim Smelley, invited Patty and me to go with them to a daylily conference in Alexandria one year. Ever since then, we’ve been growing and hybridizing daylilies and the camellias have sort of lost their luster for me.”

Bradford plans to share his conversion at a talk called “Christmas is When?” at the Southeast Louisiana Daylily Society meeting at 9:30 a.m. Saturday, March 19, at the East Bank Regional Library, 4747 W. Napoleon Ave., Metairie.

The free talk is open to the public and will be lushly illustrated with images of daylilies developed by Bradford and his wife.

In the simplest terms, to hybridize means to mix the genetic material of one variety of plant or animal with the genetic material of another, yielding a new variety.

With daylilies, the process can be as simple as gently touching the pollen-loaded anther (male part) of one parent to the pistil (female part) of the second parent.

Ideally, says Bradford, the pollen will then travel to the flower’s ovary to fertilize it and yield a seed pod. Seeds are then harvested and planted in trays, until the seedlings are ready to be planted in the ground.

“I’d guess that about 60 percent of the time, the cross-pollination works,” said Bradford.

By now, the couple has about 700 named varieties on their 3-acre property on the North Shore just outside of Covington. From those named varieties, they have created 10,000 of their own seedlings. What makes the process so rewarding, according to Bradford, is the mental exercise of choosing traits to hybridize for.

“Some daylilies have (markings called) eyes that you might want to hybridize for. Others have large ruffles, or teeth. Then, there is color,” he said. “You always want to cross reds to reds or purples to purples but not reds to whites because that will decrease the intensity of the flower color.”

The Bradfords spend about two to four hours a day outside in the garden during the flowering season, caring for and cross-breeding daylilies.

“We usually finish by around 11 because the flowers dry out when it starts to heat up, and you need the moisture in them to carry the pollen down the pistil to the ovary,” Bradford explained.

In the off season, Bradford says there is still plenty to do, including planting seeds and seedlings, discarding old plants and seedlings they don’t want to keep, treating for rust, and getting the flower beds ready for the next season.

Although both Henry and Patty Bradford revel in the hybridization work, they are attracted to different challenges.

“My favorites are bold colors — the reds, purples, oranges. But my wife likes paler colors, so she works with the pastels. She also breeds for eye patterns,” Bradford explained. “I work with both tetraploid and diploid types of daylilies, but she only works with the tetraploid because of the bigger flowers.”

At the Bradford property, thousands of daylilies are planted in the ground but not according to color.

“That means that from late April to July, there’s a real kaleidoscope of color outside,” Bradford said.

So what is it about hybridizing daylilies that feels like Christmas to Bradford?

“Every morning is a wonderful surprise when you run out to the garden to see what your plants have done overnight,” he said. “I want to try to interest gardeners in hybridizing and to encourage them to do it, so that when their own seedlings bloom, it’s like Christmas morning for them every day, too.”