Garden in Hot, Humid Climates

Southern gardeners, take heart. Silver sage, an Israeli hybrid, offers both taste and resilience.


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If you've ever tried to raise herbs in the Deep South or on the Pacific Coast, you already know that the traditional culinary herbs native to northern and central Europe wilt in the hot summers, high humidity, and mild winters. Although some heat-tolerant substitutes exist--Mexican mint marigold (Tagetes lucida), for example, stands in for French tarragon (Artemisia dracunculus ‘Sativa’)--garden sage (Salvia officinalis) has always been a drooping failure in hot climates. None of the more heat-­tolerant sages have come close to ­offering the same flavor.

A few years ago, scientists at the Agricultural Research Organization Newe Ya'ar in Israel set out to develop a sage hardy enough to raise commercially in Israel's hot, dry ­climate. They gathered garden sage clones from Israel and from Europe's Dalmatian coast (the former Yugoslavia and Albania), the source of the highest-quality commercial dried sage imported into North America. The latter includes S. officinalis gathered from the wild, three-lobed sage (S. fruticosa, ­formerly S. triloba), and hybrids between those two species. After several years of ­selection, the Israeli scientists found that a clone of S. fruticosa (number 25/16) from Mount Carmel in Israel produced ­extremely high yields of fresh and dry leaves and ­essential oil; however, the quality of the oil was disappointing.

The essential oil of the most flavorful ­garden sages from the Dalmatian coast contains relatively high levels of alpha- and beta-thujones, which have an odor of tansy, and low levels of camphor and 1,8-cineole, which smells of eucalyptus. By contrast, the oil of clone 25/16 was high in 1,8-cineole and pine-smelling alpha- and beta-pinenes and low in in alpha- and beta-thujones, producing an unsagelike odor of eucalyptus-pine.

To try to introduce the desirable higher levels of alpha- and beta-thujones into the hardy but bad-tasting Mount Carmel sage, clones of S. officinalis chosen for their chemical composition and heat tolerance were crossed with clone 25/16. The offspring were grown under harsh field conditions for two years; about 70 percent died, but the fresh yield and oil of the survivors were evaluated. After further selection, clone number 4 was deemed to have acceptable levels of the right chemical constituents. It was given the formal cultivar name ‘Newe Ya'ar’ (pronounced Neh-veh Ya-ar) after the ­Israeli research station where the research was ­carried out and introduced to the international fresh market.

Greenhouse-grown ‘Newe Ya'ar’ produces more than 5.5 pounds per square yard during the winter; other sages typically produce only about 1.8 pounds per square yard. The leaf color is an acceptable green to gray. Early flowering and long internodes (the distance between leaves on the stem), characteristics inherited from the S. fruticosa parent, reduce the yield but can be minimized in commercial cultivation by manipulation of light and temperature. Although ‘Newe Ya'ar’ is not reliably hardy outside in areas colder than Zone 8, plants can be wintered over in the greenhouse or on the windowsill (mealybugs and spider mites can be problems).

When ‘Newe Ya'ar’ arrived in fresh markets in North America in the early 1990s, a few people, including Round Top, Texas, herb gardeners Madalene Hill and Gwen Barclay, rooted the stalks and established them in their gardens. Eventually these plants were introduced into nurseries, particularly in Texas, as “silver sage.”

The plants have thrived there. “In the South we rarely carry a S. officinalis through the second year,” Hill writes. “We have ­always considered it an annual. Silver sage . . . is a wonder. I brought a plant to Round Top in December 1991. It was approximately two years old at that time. It is [now] approximately 3 feet high and 3 to 4 feet across. We have harvested for both fresh and dry and taken dozens of cuttings.”

Hill acquired her cuttings from a package labeled “oregano” that she found in the produce section of a Houston supermarket. Today, diners in San Antonio restaurants may well find their roast turkey seasoned with the progeny of that “oregano.”

Eli Putievsky is an herbal research scientist from the Division of Aromatic Plants at the Agricultural Research Organization Newe Ya'ar in Israel. Art ­Tucker is a ­research professor at Delaware State University, an ­editorial adviser at The Herb Companion's sister publication, Herbs for Health, and an herbal curmudgeon for The Herb Companion.