A guide to the culinary oreganoes BY HOLLY SHIMIZU
HAVE YOU EVER PLANTED OREGANO with the intention of cooking with it and then been disappointed by its lack of flavor? If so, don’t doubt your gardening skills; there’s a good chance that you ended up with the wrong plant. In truth, only a handful of plants in the genus Origanum can be used for flavoring food, and there are plants in at least six other genera that are referred to as culinary oreganoes. The term culinary oregano actually relates more to a particular flavor and fragrance than to any one genus. Although there are as many as 50 compounds in the essential oil of a good culinary oregano, it’s the pairing of one called carvacrol with another called thymol that gives oreganoes—whether true Origanum or otherwise—their characteristic aroma and flavor. Carvacrol is usually the more pungent of the two compounds; thymol, which is usually present in smaller amounts, is the signature smell of thyme. Levels of carvacrol and thymol can vary greatly between species, and even between individual plants within a species. When you are selecting a culinary oregano at a nursery, always rub the leaves and sniff them. If there’s no tell-tale odor, leave the plant at the store.
THE TRUE OREGANOES
Of the oreganoes with flavor, the most common is Greek oregano (Origanum vulgare subsp. hirtum), a native of the Mediterranean. The ancient Greeks and Romans used poultices of its leaves to treat sore muscles. Today, Greek oregano is considered one of the spiciest plants in the herb garden. Its hot, lively flavor blends well with other Mediterranean ingredients such as garlic, capers, olives, lemon, thyme, sage, and savory. Greek oregano will set tiny white flowers inside green bracts if allowed to flower. If you plan to dry it, however, it’s best to harvest this and other oreganoes after the flower buds have set but before they have opened.
Origanum majorana, or sweet marjoram, is a gentler-tasting herb than its Greek cousin. Adding it to a dish at the very end of the cooking process will give it a wonderful flavor of mint, spice, and savory, as well as a subtle piney aroma. Try using O. majorana to season Italian and Greek food, as well as mushrooms, salads, squash, eggplant, and most root vegetables.
With its gorgeous gray, furry rounded leaves, sweet marjoram looks as good as it tastes. Wonderful clusters of knot-shaped buds (which give rise to its other common name—knotted marjoram) open in early summer, creating a show of white-lavender-pink blooms. Originally from North Africa, sweet marjoram prefers hot, dry weather.
Gardeners who live in cooler zones will be encouraged to learn about hardy sweet marjoram (O. xmajoricum), also known as Italian oregano. A suspected hybrid of O. majorana and O. vulgare, hardy sweet marjoram thrives in USDA Zones 6 through 9, especially if given a winter mulch. Its evergreen leaves are less velvety and sweet tasting than those of sweet marjoram. Madalene Hill, the great southern herb gardener and chef from Round Top, Texas, emphatically says that hardy sweet marjoram is her favorite oregano because it’s milder than Greek oregano in flavor. She uses it in a host of ethnic foods, but especially in pasta dishes.
A Greek friend of mine prefers O. onites, or pot marjoram. Known in Greek as rigani, this Mediterranean native grows wild in Greek pastures, where grazing sheep won’t touch it because of its strong thymelike aroma. A two-foot-tall shrubby plant with pale green leaves, O. onites is hardy in Zones 7 through 9. Its high carvacrol content makes its oil a useful fungicide and disinfectant.
Imported mixtures of dry oregano often include Lebanese oregano, O. syriacum, and Spartan oregano, O. minutiflorum. Of the two, only the Lebanese oregano is grown in American gardens, and then only occasionally. Lebanese oregano is the ezov (“hyssop”) described in the Bible. Its leaves are gray green and its overall habit resembles that of pot marjoram.
Many of the plants that pass for oreganoes in the finest kitchens are actually oregano impersonators. One of the most popular is Cuban oregano (Plectranthus amboinicus), whose pungent, fleshy leaves contain spicy compounds similar to those in Greek oregano. Sometimes listed in catalogs as Coleus amboinicus, Cuban oregano is one of over 300 species of Plectranthus, many of which are native to the tropics and southern Africa. It is extremely heat tolerant, though sensitive to cold weather and hardy only in Zones 9 and 10. Cuban oregano is used to enhance the flavor of many bean dishes and soups, as well as seafood and vegetable dishes. In India, chefs batter the leaves and fry them.
Flatbread with Za’atar
NOTE: In the Middle East, za’atar recipes vary from region to region.
1/2 cup conehead thyme or Lebanese oregano
1/4 cup edible ground sumac berries
(available in Middle Eastern markets)
2 tablespoons roasted sesame seeds
1/4 teaspoon sea salt
black pepper to taste
pita bread (or flatbread)
2/3 cup olive oil
In a small bowl, combine the conehead thyme or Lebanese oregano, sumac berries, sesame seeds, sea salt, and black pepper. Brush pita with olive oil. Sprinkle the za’atar over the bread. Heat until warm in an oven preheated to 250°F. —H.S.
OREGANOES AND THEIR IMPERSONATORS
Origanum xmajoricum hardy sweet marjoram, Italian marjoram
Origanum vulgare subsp. hirtum Greek oregano
Origanum majorana sweet marjoram, knotted marjoram
||HEIGHT AND DESCRIPTION
Origanum vulgare subsp. hirtum Greek oregano Origanum majorana sweet marjoram, knotted marjoram Origanum xmajoricum hardy sweet marjoram, Italian marjoram Origanum onites pot marjoram, riganiOriganum syriacum Lebanese oregano, ezov (hyssop of the Bible)
12-24 in. Hardy perennial, groundcover with medium green, slightly hairy leaves and small white flowers. 12-18 in. Tender perennial or annual with gray-green velvety leaves and knotted white flower buds. 15-18 in. A hardy perennial with light green leaves, small white flowers. 18-24 in. Subshrub with pale green leaves, a woody stem, small white flowers. 24 in. A tender perennial with robust, large, pale green leaves and small white flowers.
Plectranthus amboinicus Cuban oregano Lippia graveolens Mexican oregano Poliomintha bustamanta (syn. P. longifolia) Mexican oregano Calamintha nepeta lesser calamint, nepetella Thymus pulegioides ‘Oregano Scented’ oregano thyme Thymbra spicata conehead thyme, Spanish organum
12 in. A tender perennial with succulent green leaves held horizontally. 36-72 in. An aromatic shrub with dark green leaves, white flowers. 8-24 in., up to 4 ft. in hot climates. A perennial with highly attractive pink-purple, tubular flowers and small shiny green leaves. 12-24 in. Short-lived perennial with attractive small gray-green leaves. Hazes of white flowers, long bloom season, reseeds. 6 in. Perennial groundcover with lavender flowers throughout summer. 12-24 in. Highly attractive subshrub with pink-purple flowers forming conical heads.
I grow Cuban oregano as an ornamental, and have found it to be an especially valuable plant for extremely hot places, such as next to a baking walkway near a reflective hardscape, or in a container in a very sunny site. Its habit of holding its fleshy, velvety, bright green leaves almost horizontally makes it a great plant for edging beds. The scalloped, white-edged leaves of the variegated form are very ornamental, and add color interest to food.
Another heat-loving oregano impersonator is Lippia graveolens, or Mexican oregano. A member of the verbena family, dried Mexican oregano is what is often sold as oregano on grocery-store spice racks. Grown mostly in Texas and Mexico, this plant bears foliage with a penetrating camphor taste, and its oils are said to inhibit bacterial growth. In warmer zones, Mexican oregano forms a three- to six-foot-tall shrub; in cooler areas, it’s a good tender perennial for a container. It can also be trained into a standard.
While Poliomintha bustamanta (also known as P. longifolia) shares the common name of Mexican oregano with Lippia graveolens, it is altogether different in appearance. At 18 to 24 inches tall, and with shiny, dark green leaves, P. bustamanta bears attractive, long, tubular flowers in many shades of pink almost all summer long. Poliomintha bustamanta thrives in the hot, dry summers of Texas and Mexico, where it is widely used for its spicy flavor. Highly decorative, P. bustamanta can be easily put to use in ornamental borders or container plantings.
Calamintha nepeta, or lesser calamint, has a strong odor and a pleasantly pungent flavor. In ancient Roman kitchens, it was used to mask the fetid odor and gamey taste of spoiling meat. In modern Italian cooking, it is referred to as nepetella, and used to season mushrooms and sauces, as well as to enhance the flavor of roasted meats, stews, and even some teas. This attractive but short-lived perennial can be grown in Zones 5 to 9, and has fine, grayish, hairy leaves and hazy clouds of small white to lilac flowers, which bees love. It also self-sows readily.
Poliomintha bustamanta (syn. P. longifolia) Mexican oregano
Lippia graveolens Mexican oregano
Plectranthus amboinicus Cuban oregano
|ZONE AND CULTIVATION NOTES
||FLAVOR AND USE
Zones 5-9. Sometimes subject to soil wilts caused by fusarium. Grows well in full sun, well-drained soil. Prune regularly and hard after blooming. Zones 9-10. Ornamental. Likes warm, dry weather. Easily grown as an annual in colder zones. Zones 6-9. Mulch well in cooler climates during winter. Prefers cooler weather and full sun. Start from cuttings. Zones 7-9. Grows well in containers. Zone 10. Grows well in containers; needs protection from cold. Zones 9-10. Very ornamental; loves hot weather. Start from root cuttings. Zones 8-10. Very ornamental; great in a container or as a topiary. Zones 7-10. Grows well in a container or border. Zones 5-9. Good for borders or containers. Zones 4-9. Grow as groundcover in sunny locations. Zones 8-9. Needs excellent drainage, so plant it high and mulch with gravel. Cut back after blooming.
A creosote-like odor. The pungent flavor adds a spicy taste perfect for Italian food, pizza, and pasta. An excellent antioxidant tea. A gentler flavor among the oreganoes that is more sweet with a savory-mint flavor that lends itself to seasoning vegetables, salads, mushrooms, and fish. Superb spicy mint flavor, considered perhaps the premier oregano for cooking. A sharp aroma, almost creosote-like. Use sparingly in food. Strong, pungent flavor, often imported as dry oregano. Use fresh leaves to spice up beans or fish with its pungency. Most popular oregano in Mexico for its dusky, lemony, camphor-like flavor that causes tingling on the tongue. Use for sausages, fish, pork, soups, and stews. Very spicy, hot, oregano flavor. Strong flavor, good with meats or in teas. Flavor is a combination of oregano and thyme. One of the culinary za’atars in the Middle East. Resinous, hot, oregano-like flavor.
For a durable and edible hardy ground-cover, try Thymus pulegioides ‘Oregano Scented’. A selection of mother-of-thyme with a slightly camphoraceous taste, oregano-scented thyme lends a spicy flavor to foods, though it has a slightly antiseptic scent. Hardy in Zones 4 through 9, oregano-scented thyme has a long bloom period, with attractive lavender flowers throughout the summer.
A close relative of oregano-scented thyme is an unusual plant known as Thymbra spicata, or conehead thyme. In Arabic, T. spicata is referred to as za’atar farsi (Persian hyssop). Its leaves, once dried, are used in the Middle Eastern spice mixture known as za’atar, which is eaten on flatbread. (See recipe, page 53.) Its nectar is the source of the famous Hymettus honey of Greece, and its essential oil is sold as Spanish origanum oil.
Conehead thyme earns its name from its bright pink flowering tips, which form distinctive cones in summer. Native to the eastern Mediterranean, it is hardy in Zones 8 and 9, and prefers to be grown in gravelly soil that is kept on the dry side. With its cone-shaped purple flowerheads, this fascinating little shrublet is a gorgeous sight sitting atop a scree bed or trough planter.
A FINAL REMINDER
If you plan to regularly harvest your herbs for cooking, you might want to experiment with growing several different types of culinary oregano. Having two or three to select from in a side-by-side comparison will help you to appreciate their differences, and to decide which ones really suit your tastes.
For more on herb gardening, visit www.hortmag.com/features.