May 11: Bitner to discuss conifers in UD Botanic Gardens lecture

May 10, 2010 under CANR News, Cooperative Extension, Events

Gardeners delight in the first blooms of a flowering shrub, the vibrant color of a summer wildflower, a deciduous tree aflame with fall foliage. But no one stops to admire the conifer, which is often reduced to hiding home foundations or grown as a solitary sentry in the middle of an expanse of lawn.

Well, a few people do stop to admire conifers, such as Richard Bitner, a Longwood Gardens teacher, board-certified anesthesiologist, and author of Conifers for Gardens: An Illustrated Encyclopedia.

Bitner will speak about conifers at a UD Botanic Gardens lecture at 7 p.m., Tuesday, May 11, in the University of Delaware’s Townsend Hall on South College Avenue in Newark. Cost is $10. To register or for more information, send email to [susanell@udel.edu] or call (302) 831-0153.

Bitner will focus on the great diversity of shapes, textures and color in this plant group and how to integrate conifers into a landscape with other woody and herbaceous plants.

Conifers are cone-bearing trees (and a few shrubs) that include such species as pines, firs, junipers, cedars, redwoods, yews and spruces. Conifers grow naturally almost everywhere in the world, including this region, which has 12 native species.

“Since they are green in the winter, conifers are often used as screens and windbreaks but they offer much on their own,” says John Frett, director of the UD Botanic Gardens. “You’ll find distinct textures in the conifers as well as varied plant form, including rounded, weeping, conical and fastigiated [narrowing toward the top].”

Like Frett and Bitner, Sue Barton is a fan of conifers. “Most home gardeners aren’t too enthused by conifers,” says Barton, the ornamental horticulture specialist for UD Cooperative Extension. “They want plants that stay green all year and flower all summer — and such a plant, of course, doesn’t exist.”

So gardeners turn to what they view as the next best thing — broadleaf evergreens, which unlike conifers, often have a spring or summer bloom period. Although Barton likes broadleaf evergreens and uses them widely, she says they can’t deliver the textural impact that conifers do.

Conifers also offer a wide range of colors, notes Barton. She uses unusually colored or variegated conifers as accent or specimen plants in her garden.

“The native Eastern red cedar has several cultivars. The most popular, Emerald Sentinel, has a blue-green color that turns purplish in the winter,” says Barton. “There are lots of blue conifers but none are native to Delaware except Emerald Sentinel.”

White pine has a silverly stripe on the needles that can give the tree an attractive grayish cast, says Barton. Although the white pine isn’t native to Delaware it is native to the East Coast. “There also are pines with yellow bands on their needles that make an interesting effect in the garden,” says Barton.

The region’s native conifers include seven pines, two cedars, a hemlock, a juniper and one deciduous conifer, a bald cypress. The pines include shortleaf, pitch, pond, table mountain, Virginia and loblolly. Delaware’s native cedars are Atlantic white cedar and Eastern red cedar.

“I have Eastern red cedar planted in my home meadow,” says Barton. “In winter, I love the look of the dark green needles next to brown winter grass. It looks even better planted near winterberry holly, which has bright red berries in winter. UD landscape engineer Tom Taylor has used the combination of Eastern red cedar and winterberry in a number of places on UD’s Newark campus.”

UD’s Botanic Gardens also has its share of Eastern red cedars and other conifers. The Clark Garden, directly in front of Townsend Hall, features an area of dwarf conifers.

Another good place to check out conifers is Winterthur’s Pinetum, which was started by Henry Algernon du Pont in 1914. This diverse collection of conifers includes pines, firs, spruces, cedars, and their relatives.

Downstate, look for mature and old-growth loblolly pine in the Inland Bays region and around the Nanticoke River, at such sites as Barnes Woods and Assawoman State Wildlife Area. In Kent County, you can find mature loblollies at the Milford Neck Conservation Area.

If you plan to add conifers to your yard, choose your site carefully. Most do best with full sun and well-drained soil. And be sure to get them into the ground at the right time.

“For most plants, spring or fall work equally well for planting. But it’s best to avoid planting evergreens in the fall,” says Barton. “So plant now.”

Article by Margo McDonough

View the full article and photos on UDaily by clicking here.

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