The Year of the Herbs–what a sweet year it will be because of the endless possibilities, the endless excitement and the endless world of herbs. They can be found in gardens, window boxes, salads, bouquets, crafts, containers and even medicines. Herbs provide fragrance, flavor, spice and beauty to our lives. They are versatile and easy to grow and come in a variety of shapes, textures and colors.
Imagine looking through a cookbook that never mentions herbs, or think of a world without fragrances and air fresheners. Contemplate brushing your teeth with no mint in the toothpaste. Visualizations of this sort can lead to the realization of the many ways that we interact with herbs every day and to a better understanding of why they are so valued for their fragrance, flavor and medicinal properties.
What is an herb?
A very fitting definition of what is really an herb was coined by Holly Shimizu, director of the U.S. Botanic Garden. She says, “Herbs are defined as plants (trees, shrubs, vines, perennials, biennials or annuals) valued historically, presently, or potentially for their flavor, fragrance, medicinal qualitites, insecticidal qualities, economic or industrial use, or in the case of dyes, for the coloring material they provide.” This definition defines herbs by their usefulness, rather than by their appearance or botanical structure. Thus, trees (such as witch hazel), bulbs (such as garlic) and shrubs (such as boxwood) are included.
Throughout history, one of the challenges of using herbs has been the uncertainty caused by the lack of taxonomical names and too many common names. For example, oregano (Origanum vulgare) has been known as wintersweet, pot marjoram, wild marjoram and Dost. We are indebted to Linnaeus, the father of taxonomy, for developing a classification system that helped to clarify plant species. Also, trying to sum up the history of individual herbs is challenging because of the different roles that each one has played, although a few historical events have had an impact upon the use of herbs and the spread of knowledge about them.
How early in history herbs came into use is unknown, but it is likely they played a substantial role in ancient civilizations. Ancient records discovered in Egypt reveal that the Egyptian people had an understanding of the healing power of herbs as early as 3500 B.C. The “Ebers Papyrus,” which was written circa 1550 B.C., lists prescriptions that Egyptians used to treat illnesses and injuries. Herbs such as basil, dill, parsley, caraway, mint and thyme were prescribed. According to Chinese legend, an emperor named Shen-Nong (ca.2737 B.C.-ca. 2698 B.C.) tasted hundreds of herbs, even poisonous ones. It is believed that many of the practices with Chinese herbs originated with Shen-Nong. Archaeological excavations have also found evidence of herbs being used in ancient Greek and Roman cultures. Hippocrates (460-377 B.C.), a Greek physician, was one of the first to classify herbs according to their usefulness for treating infirmities. Pliny the Elder (ca. 29 A.D-70 A.D.), a Roman author and naturalist devoted several of his volumes on natural history to the use of medicinal plants.
During the Medieval period or the Middle Ages, long-held superstitions often governed the use of herbs rather than solid evidence. Local herbs were used mostly by the lower classes because they could not afford expensive, imported spices. The Renaissance period brought about many of the beautiful herbals revered today as scholars sought to document their plant collections. During this time a growing knowledge of the usefulness of herbs was spreading throughout Europe with increasing speed. In 1652, Nicholas Culpeper authored Complete Herbal which documented medicinal remedies used in Europe, helping to disabuse the notion that doctor’s concoctions and tonics were the only medicine available.
In 1492, Columbus set out on a quest to discover a direct sea passage from Europe to Asia; instead he landed in the Americas. The exchange of information and plants that followed had a profound impact upon the use of herbs in Europe. Native Americans played an important role in this exchange of knowledge. Herbs have continued to be used in North America for landscaping, cooking, medicine and bath and beauty products. The same is true for many other areas of the world such as China, Italy, Spain and Africa. Furthermore, it is difficult to find a part of the world that has not been impacted by herb plants in some way.
Herbs are generally sun-lovers requiring a minimum of four to eight hours of sunlight per day. A few of them, such as sweet woodruff, lady’s mantle and chervil grow well in areas with less light. Referring to the United States Department of Agriculture’s (USDA) plant hardiness zone map (http://www.usna.usda.gov/Hardzone/ushzmap.html) can give growers a good picture of which herbs will grow in their area. The plant zones that are assigned to individual herbs are also a great guideline for determining the minimum temperatures that a plant can withstand. Zone information is a guide; microclimates or variations in climate always exist and may allow for some herbs to be grown outside of their zone.
Herb plants need a good foundation for optimum growth, and this begins with the soil. A quality soil provides good air circulation around the roots, good drainage and an adequate supply of nutrients. Poor soils can benefit from the addition of compost which can help to improve soil texture, replenish nutrients and improve water retention and/or drainage.
Herbs require a well-drained soil that is a mixture of silt, sand, and organic matter. Soils that are too acidic or alkaline can inhibit the uptake of nutrients essential for healthy plant growth. For that reason, it is advisable to monitor the soil pH level and take steps to adjust it if needed. A pH of 6.5 to 7.5 is a good range to aim for in order to encourage healthy herb growth for most herbs.
The amount of fertilizer to use on herbs varies depending upon the variety of the plant and the type of soil. On the whole, herbs require only limited amounts of fertilizer, although there are exceptions. Usually, the addition of natural fertilizers such as manure or compost is all that is needed to maintain good plant growth. Synthetic fertilizers can also be applied sparingly if needed.
Rainfall, soil type and plant variety can all affect how much water herb plants require. Herbs need supplemental watering in hot, dry conditions where the amount of rainfall is inadequate for sustained growth. Some species, such as thyme, lavender and oregano prefer to be a little on the dry side. Others, such as lovage and parsley need more moisture. Fully-grown herb plants can withstand drier conditions much better than seedlings or younger plants, which need more water to help them become established. A periodic soaking that extends deeply into the roots of an herb bed is more effective than several light sprinklings that only penetrate the surface. Mulching can help to minimize the loss of moisture and decrease the need for frequent watering. However, it is not advisable to mulch in areas with high humidity and care should be taken to keep the mulch 2-3 inches away from the crowns of the plants to avoid rot.
Harvesting methods and times for herbs vary according to the intended use of the plant, the variety and the season. A good rule of thumb is to harvest in the morning after the dew has dried or early in the evening because the foliage is cooler at these times and the essential oils are at their most concentrated. Disinfect pruners before clipping stems, leaves or flowers. Never remove more of the plant than is necessary. Also, steer clear of gathering herbs too late in the growing season. Harvesting herbs is a form of pruning, helping to maintain the plant’s shape and encourage bushy, compact growth. Place the herbs in a paper bag or a bucket of cold water after harvesting. Drying, freezing, refrigeration, microwaving or making vinegars and oils are all ways of preparing herbs for storage after harvesting.
Ten Common Herbs to Try
There are so many varieties of herbs available on the market today that it would be difficult to cover them all in one article. Ten common herbs are listed below along with some suggested varieties to try in your garden.
Basil plants come in a multitude of different varieties with distinctive fragrances such as lemon, cinnamon, anise, clove and camphor. Red-leaved varieties are available in addition to the green ones. A rich, well-drained soil in full sun is the best place to plant basil. Water basil well when the top ½”- 1” of soil is dry to the touch. Once mature, plants can be harvested repeatedly for their leaves and flowers. However, once basil is allowed to flower, leaf production declines and the taste of the leaves is compromised. Harvest or prune basil frequently to encourage bushy growth and slow-flowering. The most sought-after species (or type) for culinary use is Ocimum basilicum, which can be used in Italian dishes such as pesto, spaghetti and lasagna. Freshly chopped basil lends an unforgettable taste to green salads or it can be mixed with cubed mozzarella cheese and diced tomatoes. Experiment with growing several different varieties in the garden such as AAS Winners ‘Sweet Dani,’ ‘Thai Siam Queen,’ and ‘Purple Ruffles’ as well as ‘Genovese,’ ‘Spicy Globe,’ and ‘Mrs. Burn’s Lemon.’
In early spring, the pink, globe-shaped flowers of chives (Allium schoenoprasum) begin to bloom. This hardy perennial is a sun-lover and thrives in a moist, well-drained soil. The leaves and flowers smell and taste of onions and are often used in vegetable dishes or added to salads when a mild onion flavor is desired. Chive blossoms are used to add color and flavor to vinegars. A common baked potato can be dressed up with the addition of sour cream and chives. Garlic chives (Allium tuberosum) are a lesser-known kind with the mild taste and smell of garlic that can also be used for cooking. With both kinds of chives, trim the leaves on the outside of the plant first. The dried blossoms are used by crafters for flower arranging and potpourris.
The leaves of Coriandrum sativum are referred to as cilantro, while its seeds are called coriander. The dried seeds of coriander are one of the main ingredients in curry powder. The ground seeds are also used for making desserts and baked goods. Chopped cilantro leaves are often used in salsa and guacamole. Cilantro is an annual plant that can be difficult to grow. Sow cilantro in the garden in successive plantings to ensure a continual supply of leaves throughout the growing season. For good results, plant this herb in a light garden loam in full sun and keep the soil moist to avoid wilting. Excellent varieties to try are ‘Calypso,’ ‘Santo,’ ‘Longstanding,’ and ‘Slow Bolt.’
Would pickles ever be the same without dill? Anethum graveolens can be biennial but it is more commonly grown as an annual. Plant dill in a moist, well-drained soil located in full sun. Over the years, several shorter, more compact varieties such as ‘Bouquet,’ AAS Winner ‘Fernleaf’ and ‘Dukat’ have been offered as an alternative to taller varieties such as ‘Long Island Mammoth’ and ‘Vierling,’ making it easier to grow dill in smaller places. Young dill leaves are referred to as dill weed and they are used in salads, soups, casseroles, eggs, pasta, fish and other meats. Ground dill seed is used in condiments as well as with meat, onions and cabbage. A. graveolens has groups of small yellow flowers arranged on umbels (a flat-topped cluster), that are dried and used for crafts.
Thyme is a hardy perennial that grows well in light, well-drained soil located in full sun. There are many different species, offering variations in leaf color, flavor and fragrance. Creeping species such as Thymus praecox (creeping thyme) and Thymus serpyllum (mother-of-thyme) are welcome additions to rock gardens and flowerbed borders. Caraway thyme (T. herba-barona) is an additional creeping type that can substitute for caraway seeds in the kitchen. T. vulgaris (common thyme) is the species most commonly used for cooking, as well as the popular lemon thyme (T. xcitriodorus). Another well-known species is wooly thyme (T. pseudolanuginosus).
A beautiful and fragrant addition to the herb garden is lavender, which is used for used for crafting, cooking, and landscaping. Lavandula angustifolia (common lavender) is often used in the kitchen and it is one of the main ingredients in blends of Herbes de Provence. When planted in full sun, this hardy perennial develops nicely in a well-drained sandy loam that has been mixed with gravel. Excellent drainage is crucial to lavender’s winter survival. Lavender’s fragrance is well known and the flowers are used to make potpourris and perfume. L. latifolia, or spike lavender, is used in soap. Lavandin (L. xintermedia) is the product of a cross of spike lavender and common lavender. The essential oil of Lavandin is used to make soap, perfume and household cleaners. Many cultivars of lavender are available such as AAS Winner ‘Lavender Lady,’ ‘Hidcote Blue,’ ‘Munstead,’ ‘Kew Red’ and ‘Gray Lady,’ each one varying in flower color and leaf shape.
Greek oregano (Origanum vulgare subsp. hirtum) and its counterpart marjoram (O. majorana) are popular culinary herbs used in stuffing, casseroles, soups, stews, egg dishes and meat dishes. Greek oregano has a sizzling, spicy flavor, while marjoram is milder and sweeter. Both are perennials that favor well-drained soil and full sun. Cultivars to try in the garden include ‘Herrenhausen,’ ‘Amethyst Falls,’ ‘Kent Beauty,’ ‘Zaatar,’ ‘Greek’ and ‘Hot and Spicy.’
Melissa officinalis, better known as lemon balm, is a perennial herb that is best grown in a moist, well-drained soil in full sun or partial shade. However, it is not choosy, and can quickly become invasive if not contained. It also spreads by seed, so spent flowers should be removed. Planting in containers is a good way to keep control of this prolific grower. The lemon-scented leaves are used in teas and desserts. They can also be dried and used for crafts. Cultivars include ‘Aurea,’ ‘Citronella’ and ‘Lime.’
Two types of parsley are commonly grown in herb gardens: namely, common or curled- leaf parsley (Petroselinum crispum) and flat-leaved or Italian parsley (P. crispum var. neapolitanum). Both types are used in the kitchen and can be added to soups, stews, casseroles and meat dishes; although Italian parsley is often the first choice for cooking. Curled parsley is eye-catching and is often used as a garnish. A well-drained moist garden loam is excellent for growing parsley; the soil should be kept moist to avoid wilting. This herb can be grown as an annual or as a biennial.
Sages come in a variety of flower colors and fragrances. Garden sage (Salvia officinalis) is the one used in the kitchen and is known as a flavoring for turkey, stuffing and sausage. Pineapple sage (S. elegans) produces vivid scarlet-red flowers in the fall. Sages are perennial herbs that should be grown in full sun in a well-drained garden loam. Not all sages are edible and some varieties are grown for landscaping purposes only. Cultivars include 'Berggarten,' 'Kew Gold,' 'Tri-color' and 'Purpurascens.'
Hemphill, Ian. The Spice and Herb Bible. Ontario, Canada: Robert Rose Inc., 2000.
Siktberg, Robin and Janeen Wright, eds. The Beginner’s Herb Garden, Fourth Edition. Kirtland, OH: The Herb Society of America, 2010.
Tucker, Art and Thomas DeBaggio. The Big Book of Herbs. Portland, Oregon: Timber Press, Inc., 2009.
For More Information
Please consider our NGB member companies as authoritative sources for information. At www.ngb.org click on direct links to their websites by selecting Member Info from the upper left menu for the Complete Member List. Gardeners looking for seed sources, select companies listed as Retail.
The National Garden Bureau recognizes The Herb Society of America www.herbsociety.org as the author of this fact sheet.