Gardens: Thomas Jefferson's gardening legacy

New gardeners smitten with the experience of growing their own food might be both inspired and comforted by the highs and lows recorded by Thomas Jefferson, third president of the United States, from the sun-baked terraces of his two-acre kitchen garden 200 years ago.

And they could learn a thing or two from the 19th-century techniques still being used at Monticello, just outside Charlottesville, Virginia, today.

"He was experimental and had a lot of failures," says Peter Hatch, director of gardens and grounds at Monticello, as we stand in the terraced garden that took seven slaves three years to cut into the hill. "But Jefferson always believed 'the failure of one thing is repaired by the success of another'."

After he left the White House, in 1809, and moved to his Palladian estate at Monticello, Jefferson grew 170 varieties of fruits and 330 varieties of vegetables and herbs, until his death in 1826.

As we walk along the geometric beds I make notes on the beautiful crops I have never grown. Sea kale, with its great, ruffled blue-green leaves, now full of little round seed pods. Egyptian onions, whose tall green stalks bear quirky hats of tiny seeds and wavy green sprouts. A pre-Columbian tomato "purple calabash", whose energetic vines will soon be trained up a cedar trellis made of posts cut from the woods.

"Purple calabash is one of my favourites," Hatch says. "It's an acidic, almost black tomato, with a convoluted, heavily lobed shape."

Hatch, who has directed the restoration of the gardens here since 1979, has pored over Jefferson's garden notes and distilled that knowledge in Thomas Jefferson's Revolutionary Garden, to be published by Yale University Press.

Jefferson collected seeds and cuttings from around the world and distributed them to others, only to have them die in his own garden.

"Jefferson would kill the thing at Monticello then go back to George Divers and say, 'what happened to those black-eyed peas I brought back from France in 1789?"' Hatch says, referring to Jefferson's neighbour, a better gardener who usually won their pea-growing contest. Jefferson's eagerness to give away seeds and plants was "a great lesson about sharing stuff, so that when it dies at your house, you can go to your neighbours for a replacement," Hatch says.

There are many such deaths - from drought, insects and disease - recorded in Jefferson's garden book between 1766 and 1824. His meticulous calendar, which documents when each seed was sown, when it sprouted, flowered and came to table or died, serves as a rough guide for Hatch today.

Hatch recounts a plague of insects descending on Monticello while Jefferson was away, and his daughter Martha writing to him in despair. "Jefferson wrote back and said the problem was the crummy soil," Hatch says. "He told his daughter that when he returned, the two of them would cover the entire garden with a heavy coating of dung."

At Monticello, the gardeners dig in plenty of homemade compost and aged manure into the soil. But allegiance to Jefferson's methods goes only so far.

When flea beetles - known to Jefferson as turnip flies - hit the aubergine seedlings this spring, gardeners sprayed them with insecticidal soap. They will use other pesticides, as benign as possible, to save crops. Now, those aubergine seedlings are hefty three-footers.

The intense heat and humidity of a Virginia summer explains why colonial gardens were planted only in spring and toward the end of summer, when temperatures cooled. But Jefferson gardened year-round, planting early in heat-collecting beds along the mountain slope and growing heat-loving crops such as okra, melons and tomatoes during the scorching summers. He also grew cool-season lettuces long past their time in the low-lying, damper areas farther down the mountain.

Jefferson's biggest mistake was to put his monumental, 1,000-foot-long garden on the south side of this mountain, where it is in full sun from dawn to dusk, with no water source. The restored vegetable garden here is watered by overhead sprinklers supplied by a 30,000-gallon cistern fed by a spring a half-mile down the mountain. If Jefferson's slaves hauled barrels of water from there on a mule-drawn wagon, there is no record of it.

We might think farmers' markets are new, but the Washington farmers' market was thriving when Jefferson was in the White House. He avidly supported its farmers, bringing them seeds collected by his consuls in their respective countries, as well as seeds and cuttings from his own plantation, where crops from Africa and the Americas flourished.

Hatch sees the okra soup that came out of the Monticello kitchen as a melting pot of international crops and cuisine. It included cimlins (squash) and lima beans, tomatoes from Central America and okra from Africa, where it was "creolised," as Hatch put it, by French and African-American cooks.

Now that the Obamas are growing vegetables on the south lawn of the White House, Monticello has become a source of heirloom varieties like "tennis ball" lettuce and "Texas bird" peppers.

Pat Brodowski, Monticello's head gardener, sees me eying the round seed pods of the sea kale and clips off a few of the dried stems. "The seed doesn't stay viable very long, so plant them in a pot as soon as you get home," she says.

Sea kale is a true perennial that can be wintered over, if protected by mulch. The plant dies down to the ground, but in spring its tender shoots can be eaten like asparagus. At Monticello, the shoots are protected by upside-down clay pots in early spring. Then the pots are removed and the unfurling leaves are enjoyed as ornamentals, sending up stalks covered with tiny white flowers.

Monticello's gardeners dressed the asparagus beds and sowed peas in February, after practices Jefferson recorded in his calendar. "But we don't sow a thimbleful of lettuce every Monday morning," as Jefferson did, Brodowski says.

Jefferson's ritual is good advice for today's kitchen gardeners, because successive plantings of small amounts of seed keep everything from maturing at once. But when it comes to lettuce, a cool-season crop that grows bitter and goes to seed as soon as hot weather arrives, Brodowski ignores Jefferson's advice.

"He really wasn't a very good gardener," she laughs. "He was adventurous."

'Jefferson always believed 'the failure of one thing is repaired by the success of another'

This article was first published in The Scotsman on Saturday, 4 September, 2010