Walk across a carpet of thyme, and you will understand why European settlers brought it to the United States and why it continues to be one of the most beloved herbs in the garden. The aroma is warm and exotic; the foliage is finely textured. While some selections of thyme are essential in the kitchen, others are among the most appealing herbs for landscaping. The upright types grow into small shrubs, while the creeping ones contain a variety of flower and foliage colors. Thyme is evergreen throughout much of the South?you can harvest culinary types for soups, stews, stocks, bouquets garnis, vegetables, and meat dishes all winter long.
In the Landscape
No matter what the season, thyme puts on a show. Its evergreen foliage provides anchor in an herb garden in winter and varies in color from dark green to silver and gold to variegated. In early spring, the flowers open, sprinkling the plant with spots of white, pink, lavender, or rose.
Use shrublike upright selections in borders or as small hedges. Plant creeping selections as edgings or ground covers, between paving stones, or along rock walls. No other herb serves to soften hard lines or angles as well as thyme does. Thyme also makes an ideal container plant. It is drought tolerant and thrives in the superior soil and good drainage provided in a container.
Planting and Care
Thyme does best in full sun to partial shade, but not in deep shade. It is easiest to start from transplants set out in the fall or in spring as soon as the soil warms. Seeds of most selections do not germinate easily and are difficult to handle because of their small size.
Plant thyme in light, well-drained soil with a pH of 6.0 to 6.7. Add a slow-release fertilizer to the soil before or during planting and again each spring. Thyme must have excellent drainage to succeed in the South. Mulch to conserve moisture, but add a ring of builder's sand around the crown to prevent root rot. With a layer of protective mulch, most selections of upright thyme are cold hardy through Zone 5. However, do not mulch mat-forming types or they will rot.
Propagate thyme by stem cuttings or by divisions in fall or early spring. Creeping selections can also be propagated by layering.
Given proper growing conditions, thyme will need little care besides a regular light pruning, starting in the spring, to prevent it from becoming woody and brittle. Prune upright selections by one-third in spring to keep them shapely. Creeping types often become ragged in winter; if this happens, cut them back to the ground in late winter before spring growth begins.
Species and Selections
There are dozens of selections of thyme. The basic difference between them is that some are grown for culinary use and others are used primarily in landscaping. Both types are edible, but creeping thymes are usually small and tedious to harvest and are therefore more valuable as ground covers.
Garden thyme (Thymus vulgaris), also known as common, English, or French thyme, is most often used as a seasoning. The flavor of this hardy perennial is pungent and strong. Plants grow upright and range in height from 8 to 12 inches depending on the selection. Trim plants to keep them neat and to prevent them from getting too woody. English thyme has dark green, oval leaves, and French thyme has narrow gray leaves.
One of the most popular culinary thymes, lemon thyme (Thymus serpyllum) is known for its enticing lemon scent and taste. Sometimes listed in catalogs as Thymus x citriodorus, it is a hardy perennial that grows 4 to 12 inches tall. Leaves may be green or edged in yellow, depending on the selection. Lemon thyme spreads rapidly and bears pinkish flowers in summer. The green form is the best for culinary use.
Known for its beautiful rose-purple flowers that bloom in early summer, caraway thyme (Thymus herba-barona) has a mild caraway flavor. It is a hardy perennial that grows 2 to 5 inches tall, with narrow green leaves. Caraway has a neat growth habit that requires minimal pruning; however, the plant spreads rapidly.
Mother-of-thyme (Thymus praecox Arcticus), also called creeping thyme, grows 3 to 5 inches tall and is used primarily as an ornamental. It has tiny oval leaves and bears purple flowers in early summer. Plants spread by rhizomes. Cut this selection to the ground in spring to get rid of the ragged growth left from winter. Mother-of-thyme is not reliably hardy north of Zone 7. There are a number of selections with different flower and leaf colors.
Harvest, Storage, and Use
Harvest thyme leaves as you need them. The flavor is most concentrated just before plants bloom. Strip leaves from woody stems before using. Keep the stems on coals when grilling to add flavor to foods.
Because thyme usually stays green through the winter, it does not need to be preserved. But for convenience, thyme can be easily dried, stored in oil, stored in vinegar, refrigerated, or frozen. Let the foliage air-dry. Store in an airtight container.
Make thyme butter for basting seafood, chicken, or pork. Add thyme to mayonnaise (2 tablespoons fresh chopped thyme to 1 cup mayonnaise) for sandwiches or to dried beans, meat stews, or vegetables, such as cabbage. Use it to flavor rice or new potatoes (along with garlic, butter, and Parmesan cheese). Add thyme to any slow-cooked dish (especially soups and stews) and to sautéed vegetables, broiled or roasted meat or poultry, breads, and sauces.
Thyme is also one of the best herbs to use for wreaths and other crafts.
Thyme can suffer from root rot and fungal diseases if not given proper drainage. The herb also attracts spider mites.