By Adrian Higgins
Thursday, March 5, 2009
My herb garden is tiny, measuring about 24 square feet, but it has supplied the kitchen over the years with ample fresh rosemary, thyme, mint, oregano, basil and more.
Culinary herbs keep giving, to a point. After a few short years, they peter out -- even perennial herbs that are well tended and regularly harvested -- a practice that keeps them young and vigorous. Early March is the best time to rework the herb garden so that it is ready for planting in a month.
I rejuvenate the herb garden every three years or so by taking out old and tired sage, lavender and rosemary plants. Working the soil also allows me to remove any wayward tree roots and mint roots lurking there. I add bags of aged compost, peat and topsoil and incorporate them into the bed, along with some bone meal and a few cups of powdered limestone, to give the soil the sweetness that most herbs prefer. After raking, I leave it for a few weeks: It's still too cold to plant herbs that have spent the winter in the greenhouse, and the cultivated earth needs time to settle an inch or two.
Of course, shopping for little potted herbs at the end of March is one of the highlights of the gardening year. What perfect things they are: beautiful, aromatic, useful, easy to grow and rich in history and myth. Just remember to keep them in their pots so you can put them in a sheltered spot and then bring them into an unheated space at night. Do that for a few nights before planting to acclimate them to life outdoors.
If you don't have an herb patch to rejuvenate, see my plan at right for a modest herb garden measuring 4 by 8 feet, which will keep the cook in your family supplied with fresh herbs from April to December. Select a site that is level, sunny (at least six hours of sunlight daily) and close to the kitchen. One caveat: If you live in an old house, the soil next to it may contain unacceptable levels of lead from flaking house paint. If in doubt, ask your county extension agent how to get samples tested at a soil laboratory.
Perhaps the ideal site is on part of the lawn. You can skim off the grass with a sharp shovel and dig the ground to provide depth to the bed. Still, framing the garden with six- or eight-inch-wide boards will allow for deeper, richer soil and give it the free-draining qualities that herbs require. Use untreated wood (rot resistant cedar is perfect), and secure the boards with 12-inch wooden or metal stakes.
Hundreds of varieties of culinary herbs will grow in the Washington area, though gray-leafed Mediterranean herbs begrudge the heat and humidity and hate soil that stays wet. Mulch them with pea gravel to keep crowns from rotting.
Your 4-by-8 garden will house more than a dozen varieties, and you can add more in pots. Here are my suggestions for classic culinary herbs, and a few exotic additions.
Rosemary. Hardy varieties have been developed that are a safe bet for multiyear survival in Washington, but they tend to be coarse in form and flavor. If you have a sheltered site, especially inside the Capital Beltway, more tender types are reliable. I find some of the supposedly tender ones more finely textured and pungent, namely Tuscan Blue and Salem. Browsing the Web site of DeBaggio's Herb Farm & Nursery in Chantilly (http://www.debaggioherbs.com), I am enticed to try two others, Blue Spire and Mrs. Reeds Dark Blue.
Sage. The variegated and colored sages Tricolor, Purpurea and Aurea are pretty but not the best for culinary use. Choose the regular garden sage (Salvia officinalis) or an attractive compact variety of it called Berggarten.
Thyme. Of the many types of thyme, common thyme (Thymus vulgaris) and its cultivated varieties are the best for cooking, including the so-called French thyme with its narrow and curled leaves. Golden lemon thyme is also worth growing for its citrus scent and attractive yellow leaf margins.
Oregano. Italian oregano is the classic culinary form, but grow Greek oregano, too, for its more pungent flavor. Their cousin, sweet marjoram, is grown as an annual and is favored for its milder flavor and beauty.
Savory. Savory is a small-leaf, aromatic herb worth getting to know. The best culinary savory is summer savory, an annual with upright stems. "But you have to plant a lot of it," said Chrissy Moore, curator of the National Herb Garden at the U.S. National Arboretum. She grows a perennial species called creeping savory, which is still a valuable culinary herb used to season vegetables and soups. Winter savory is a handsome evergreen but not as yummy.
Cilantro. Refreshingly spicy, cilantro is favored in Mexican and Asian cuisine. It's a cool-season annual grown in the spring and fall. Sow seeds this month and in mid-August. If cilantro is not to your taste, use chervil instead. Chervil is another leafy herb for spring and fall with a flavor between parsley and anise crop. It is used a lot in French cooking.
French tarragon. This aromatic perennial's leaf flavorings go a long way, so harvest sparingly. Brush and smell the foliage before buying it to avoid getting the similar but useless Russian tarragon.
Sweet basil. Many types of basil are available, including Asian varieties, but the standard Genovese is the one to grow. It hates cold conditions, so don't plant until May. It's a good follow-on crop after cilantro. Three plants should keep you in basil for the season, though tired plants covered in flower spikes can be replaced in August.
Mint. The National Herb Garden's Moore recommends a superb culinary peppermint named Blue Balsam. You can contain it in a pot, with adequate watering, though its tendency to spread in the ground can be checked with regular pulling, said Holly Shimizu, executive director of the U.S. Botanic Garden.
Lemon grass. This is a tender grass used a lot in Thai cuisine, and it will grow happily to about four feet. Make sure you are buying the culinary version, Shimizu said. The grass should have a bulbous swelling at the base of each leaf.
Parsley and celery leaf. Cooks tend to prefer flat-leaf or Italian parsley, but Shimizu, an herb expert, finds more flavor in curled-leaf varieties. Parsley dislikes summer's heat, so consider replacing stressed plants in late August for a fresh fall crop. Celery leaf, sometimes called cutting celery, adds celery flavor to dishes without the texture or stringiness of celery stalks, which are difficult to grow in our climate.
Chives and garlic chives. Chives add a mild onion flavor in the kitchen and look beautiful in the garden, especially when they produce their dainty violet blue flowers in late spring. The blossoms are edible, too, but pick only single florets. The whole flower would overwhelm the palate, Shimizu said. Garlic chives have a stronger flavor. They also produce attractive white flowers on two-foot stalks in September.
Dill and fennel. These are easy, almost weedy herbs to grow from seed and are used to flavor salads and meat. Dill pairs well with fish and is used for pickling. Sow fresh seed in summer for a fall crop. Bronze fennel is a non-bulbing type with purple red foliage. It looks as good as it tastes.
Nasturtium. The leaves and flowers are edible and have a peppery kick. Nasturtium grows happily from seed and can be used to frame an herb garden economically. Soak the seeds in hot water for 24 hours before planting. Sow two or three seeds every 12 inches, and thin to one seedling after germination. Providing deep, rich soil will reduce the flower display but allow nasturtium, which prefers a cooler climate, to develop a healthy root system before summer's heat arrives. Use a mounding rather than a climbing variety. Shimizu recommends Alaska Mix, which has variegated foliage and is not as attractive to black aphids as other nasturtiums. The insects can be sprayed off with water.