He pushes the limits in growing holly

Bill Cannon hopes the baggage checkers on his next flight home won't open his suitcase. No, he's not carrying contraband. The horticulturist would just prefer not to explain the presence of dozens of holly cuttings swaddled in newsprint.

When Mr. Cannon travels to holly meetings, growers press him to try their newest varieties. As his reputation has grown, so has the need for suitcases, much to his wife's chagrin. "I try to clean them out as well as I can," he says.

To visit Cannon's property in Brewster, Mass., on Cape Cod, is to witness a decades-long "addiction" to hollies, some of which were grown by Cannon's father and grandfather. On a one-acre lot that includes the house, Cannon grows 260 different varieties of holly, from 50-foot trees to the tiny 'Rock Garden' hybrid, which is less than 12 inches tall.

His claim to fame: cultivating varieties that by rights shouldn't grow this far north. By a trick of climate, Cape Cod winters are usually warmer than in the rest of the region. So Cannon likes to push the envelope. He is raising the unappealingly named Ilex vomitoria (Yaupon holly), which generally lives in regions where temperatures rarely fall below zero.

Few people can resist his enthusiasm for holly. As he shows a group of slicker-clad garden-club ladies around the yard on this drizzly, cold day, he speaks rapturously of glossy leaves, shiny berries, and conical shapes. He knows each holly by name, and touches the branches as if greeting dear friends.

The ladies are agog at his knowledge - and his stories. They laugh when he tells of a Southern gentle- man who spoke of the spiky virtues of the Chinese holly 'Berries Jubilee,' humorously explaining, "Around here, that's what we plant under our teenage daughters' windows."

If the genus Ilex ever needed a goodwill ambassador, Cannon would be the man. "Most people know only two or three types of holly that they see at Christmas," he says. "They don't know how hard growers are working to expand the range of hollies" available to home gardeners. Hybridizers are looking for plants with darker green, shiny leaves; greater resistance to insects and diseases; a more compact shape that needs little pruning; and plants that bear fruit at a younger age.

Right now, at least 500 varieties of American holly are in commercial production in the United States. And that doesn't begin to measure the plant's scope: Gardeners enjoy Japanese holly, Chinese holly, English holly, deciduous types, and many more. They're also looking for exotic varieties, including those with variegated leaves or orange berries.

Specialty nurseries are struggling to keep pace, but in local garden centers, it's rare to find more than eight or 10 types of holly.

That is, unless you live in the mid-Atlantic, "a hotbed of holly enthusiasts," according to Cannon. Other areas where hollies are very popular include Tennessee and Georgia, and France, England, Australia, and Korea.

Cannon, who retired from managing a nursery in Abington, Mass., has developed his own cultivars, or varieties, of holly, many of which he has named after his grandchildren.

This year, he registered a new cultivar called 'Purple Frost' (not named for a family member) with the American Holly Society. It is a seedling of a "blue" Meserve holly that changes from bright green leaves in spring to dark, wine-red leaves in the fall. Each year, about 20 new cultivars are registered in the US, many of which then begin the slow process toward commercial production.

Of the hollies Cannon grows, about three-quarters are available commercially. Determined gardeners can find the unusual varieties at plant society and botanical garden sales.

Like many gardeners, Cannon can never find enough time to prune or weed. Right now, he's managing two properties - his home in Abington where he is empty-nesting with his wife, and the Cape house and yard where he hopes to move next year, "after we update the kitchen."

The Cape property definitely needs some "editing." In addition to hollies, Cannon inherited a dawn redwood that long ago dwarfed the house, a magnificent 'Dr. Merrill' magnolia, and a huge Chinese witch hazel. ("People stop their cars to say, 'Your forsythia is blooming early,' " he says of the yellow witch hazel blossoms that appear in January or February.) All could benefit from their own spot in the sun.

In the backyard, Cannon wants to open up a space in the boxwood hedge so he can enjoy the allée, or row of trees, from his back door. If only he could create a bit more room, take away a holly here or there, maybe put in an archway. He's certainly not daunted by the tasks ahead.

"I love working in the garden," he says. "I can come down here and just lose myself."

Planting: Hollies can be planted in spring and fall, but new shrubs need protection from drying winds and sun. To do this, place three stakes around the tree, and wrap the burlap around them so the burlap isn't touching the plant.

To ensure berries: Buy a male and female holly of similar type. For example, if you buy an English holly, nearly any other male English holly will pollinate it. Pollination brings blooms, which become berries.

Siting: More sun means more berries. In many cases, variegated hollies show more variegation if they have plenty of sun.

To help prevent winter burn: Spray with Wilt-pruf, an antidesiccant. Not everyone is convinced it works, but it's worth a try if you live in a cold-winter climate.

Mulching: Use bark mulch, which stabilizes the soil temperature and enriches the soil as it breaks down.

Fertilizer: If you sprinkle holly fertilizer on top of the mulch, instead of scratching it into the soil, you run less risk of damaging shallow roots.

• For more information, see www.hollysocam.org.