Secrets behind a garden wall: clever growing tricks from an Idaho gardener - Garden & Outdoor Living

Sunset, May, 2003 by Suzanne Touchette Kelso

On the west side of Alex and Gina Macdonald's contemporary log home in Ketchum, Idaho, a drystacked stone wall surrounds the garden. The artfully arranged stones form a picturesque and utilitarian barrier, which allows the Macdonalds to grow a bountiful array of flowers and vegetables that would otherwise be devoured by passing deer and elk. The wall also creates a warmer microclimate, extending the too-short growing season here at an elevation of 6,500 feet.

The inspiration for the walled garden came during a trip the Macdonalds took to Provence. In France, they saw ancient stone walls surrounding virtually every garden.

Back home in Ketchum, Gina--a veteran gardener, farmer, and rancher--worked with Webb Landscape to design walls that would be sturdy enough to keep Out elk and withstand a heavy snow load in winter. Using buff-colored Utah sandstone, they built 7-foot-tall walls that taper from 4 feet wide at the base to 2 feet wide at the top.

Besides barring unwanted wildlife from the expansive garden, the walls block the cold wind, and the stone retains solar heat that radiates into the garden. The longest walls, which face west and south, receive maximum solar exposure. Consequently, the garden stays about 100 warmer than the ambient air temperature. Gina figures that the wall extends Ketchum's average 75-day growing season by at least 21 days.

To squeeze even more abundance out of the short summer, Gina employs other devices. Early in the season or whenever temperatures dip, she shields vegetables with row covers or plastic sheeting suspended over frames made of metal or PVC pipe. She grows warmth-loving artichokes, basil, and tomatoes in a 120-square-foot plastic greenhouse.

In addition to edibles, Gina grows 30 kinds of perennials. Near the house, which bounds one side of the garden, she grows towering delphiniums and hollyhocks for their strong vertical interest. Nearby, peonies yield soft pink blossoms that she harvests for indoor arrangements. Gina likes carnations and sweet Williams for their spicy fragrance and season-long color. Indestructible bearded irises are scattered throughout the garden. She keeps lavenders and lemon trees in pots, which she moves indoors for winter. She plants tender climbing vines such as wisteria and sweet peas so they can cling to the warm stone walls. As for roses, Gina favors cold-hardy, repeat-blooming varieties from the Canadian Explorer series, including 'William Baffin', 'Martin Frobisher', and 'Jens Munk'.

Each spring, Gina broadcasts granular fertilizer over the flower beds. Starting in June, she scatters dry fishmeal over the entire garden once a month. In early and midsummer, she spreads a 1- to 2-inch layer of compost around vegetable plants. In autumn she cuts back perennials and wraps roses with insulated shrub cloth. Then she covers the entire garden with a mulch of fine bark mixed with well-rotted steer manure, applying 1 to 2 inches over vegetable beds and 3 to 5 inches over perennials. The manure breaks down over winter and is ready to provide gentle nourishment to crops and flowers when the growing season begins.

WALL DESIGN: Webb Landscape, Ketchum, ID (www.webbland.com or 208/726-4927)

RELATED ARTICLE: Gina's favorite plants

FLOWERS

Bearded iris 'Sugar Blues'

Bee balm 'Scorpio'

Columbine McKana Giants

Delphinium

Magic Fountains Mix

Dianthus 'Zing Rose'

Foxglove 'Apricot'

Gaillardia x grandiflora

'Portola Giants'

Hollyhock 'Charter's Double'

Lavender 'Provence'

Peony Raspberry Sundae'

Purple coneflower 'Magnus'

Rudbeckia hirta

Rustic Colors Mix

Scabiosa atropurpurea

Imperial Giants Mix

Shasta daisy

'Christine Hagemann'

Sweet William 'Magic Cherry'

VEGETABLES

Asparagus 'Jersey Giant'

Broccoli 'Bonanza'

Carrot 'Royal Chantenay

Green bean 'Vernandon'

Lettuce Napa Valley Lettuce Mix

Pea 'Super Sugar Snap

Potatoes 'All Blue', 'Kerr's Pink', 'Peruvian Purple', 'Yukon Gold'

Spinach 'Bloomsdale Longstanding'

Strawberry 'Tristar'

Tomatoes 'Brandywine', 'Early Girl', 'Super Sweet 100'

SOURCES

Flowers: Many of the plants on Gina's list are sold by White Flower Farm (www.whiteflowerfarm.com or 800/503-9624) and Wayside Gardens (www.waysidegardens.com or 800/845-1124), which also sells Canadian Explorer series roses.

Vegetables: Seeds for many of the varieties mentioned are available from W. Atlee Burpee & Co. (www.burpee.com or 800/888-1447) and Shepherd's Garden Seeds (www.shepherdseeds.com or 800/503-9624), which also offers an assortment of seed potatoes.

Row covers: These are available from Charley's Greenhouse (www.charleysgreenhouse.com or 800/322-4707) and Gardener's Supply Company (www.gardeners.com or 800/863-1700).

Gina's secrets for success

Jump-start veggies. Plastic sheeting over PVC frames gives extra warmth to lettuce (front) and broccoli (rear) in chilly weather.

Some like it hot. Tender crops like tomatoes and basil thrive in the warmer air and soil inside the greenhouse.

No bare ground. Closely spaced plants keep out weeds. Here, irises and gladiolus are underplanted with Johnny-jump-ups and marigolds.