While hiking in Little Cottonwood Canyon many years ago, I noticed a very interesting plant growing out of the gray limestone rocks.

I was attracted to its interesting rounded leaves and wispy red blossoms.

After investigating, I determined it was coral bells. It was a member of the Heuchera (pronounced hoo-ker-a) genus, with some 50 species and numerous cultivars.

The plants are also known as alum root.

From these plants have come many others. They are one of the darlings of the perennial world. Their explosive popularity comes from the introduction of the many new cultivars that propagators have introduced to the gardening public.

One leader in this effort is Terra Nova Nurseries Inc. in Canby, Ore. During my visit there last summer, I visited with Chuck Pavlich, director of new product development.

Pavlich explained how the company started.

"Dan Heims and his wife, Lynne Bartenstein, are co-owners. Dan had a landscaping business and was fooling around with plants as a hobby.

"He eventually entered into a partnership with Ken Brown and his wife, Jody. Brown was a microbiologist by training and taught himself how to do tissue culture using an old aquarium," Pavlich said.

From this humble beginning has come a world-class company. Terra Nova's avalanche of colors has flooded gardeners, retailers and propagators and has left them clamoring for more.

When I asked what made Heims specifically target Heucheras, Pavlich explained that Dan is a begonia nut.

"He has hundreds of varieties at the nursery," Pavlich said. "As you know, Rex begonias have colored and patterned leaves. He wanted a hardy begonia, and that is what he was initially aiming for in his Heuchera breeding."

As Heims searched for that elusive plant, he turned over another hidden diamond. The Heucheras were very cold hardy, very colorful and a relatively unknown garden perennial.

As the business grew, Terra Nova expanded its micro propagation labs, greenhouse and other growing areas. Additional employees also included a full-time plant breeder.

Tissue culture has enabled Terra Nova to introduce new cultivars to the market very rapidly. Previously, perennials were planted and eventually dug and divided into a few plants, but that process could take decades to produce enough plants to get to market.

"When we do tissue culture," Pavlich explained, "we take a small piece of the center or heart of the plant and put it into sterile media with growth hormones. The cells grow and form callus tissue, which we then take and divide to grow more plants."

"This process is no different than taking a cutting from a plant stem and rooting it. We are not modifying the plant; we are just doing it like nature and producing identical plants or clones on a small scale.

"We get most new cultivars from our cross-breeding program," he continued. "Occasionally, we find a mutation, but most of these have no commercial value because of plant instability or inherent weaknesses."

Terra Nova's breeding program has produced 110 Heuchera offerings, but the company isn't about to stop. "We are not done with Heucheras yet," Pavlich said. "We see new leaf shapes and sizes. We also see new flowers, as both landscape plants and as cut flowers. We are also breeding to get more resistance to diseases and tolerance of humidity."

"If you could see our trial house right now, you would go nuts. Terra Nova's model has always been eye candy, but we are adding a lot more to that."

Anyone can find a spot for these plants in their garden. They grow well in sun or partial shade, with flowers that range from white to cream through light and dark pink and red. The low, mounded clumps of leaves are evergreen into the winter.

Few plants have the range of colors that these plants show in their foliage, with striking shades of purple, silver green and golden shades.

Add the multiple colors and the variegations, and it is like the rainbow is appearing in your garden.

Fortunately, local nurseries are well stocked with what you need to paint those living rainbows. Use you shovel, not your brush, and get started.

Garden tips and events

Visit Terra Nova Nurseries online at www.terranovanurseries.com. There, you'll find fun information on Heucheras and many other plants, as well as links to local retailers.

Wasatch Community Gardens is celebrating urban "eggriculture" with Chicken Week, June 21-26.Go to wasatchgardens.org for more information.

Bill King will discuss William Robinson, famous gardener and author of "The English Garden," during the free Garden Talks in the Park, June 16, 8 p.m., a the Brigham Young Historic Park, State Street and Second Avenue.

Larry A. Sagers is a horticulture specialist for the Utah State University Extension Service at Thanksgiving Point.