Thyme is actually a large group of herbaceous and evergreen plants with both upright and trailing or spreading varieties. Most types of thyme are hardy in USDA Zones 5-9, so the simple answer to the question of "Is thyme a perennial?" is yes, thyme plants are perennials that can live for many years. Here's what you need to know about the different types of thyme, and how to care for them to ensure these perennials thrive in your garden for many seasons to come.
If you garden in a colder place than Zone 5, you can either bring your thyme indoors at the end of the growing season and keep it as a houseplant, or grow thyme as an annual that you would need to replace in spring.
Types of Culinary Thyme
Many gardeners grow culinary thyme as an annual, buying pre-started plants in spring, growing them for harvest in summer and early fall, and then composting the plant at the end of the season. But when shopping for thyme plants to grow for eating, you may be perplexed by the variation in common names. That's because the culinary type of thyme (Thymus vulgaris) comes in many varieties. You might come across German thyme, English thyme, summer and winter thyme, French thyme, and creeping thyme. Perhaps the most commonly seen are summer thyme and winter thyme.
Summer thyme, also called French thyme, is a smaller plant with a light flavor. Winter thyme, also called German thyme, is a bit larger and more cold-hardy. English thyme is a third variety of T. vulgaris, often called common or garden thyme. It is viewed as having the strongest flavor of the three. All of these culinary thyme varieties are perennial plants. And each one is tasty when harvested and added to recipes. They just have slightly different growth habits and flavors.
Other Popular Types of Thyme
You can grow culinary thyme as well as other types of thyme just for their good looks and pleasant fragrance. Popular types of thyme to grow as perennials in your garden beds and containers include:
- Creeping thyme (Thymus serpyllum) is a tough, drought-tolerant groundcover that is sometimes used to replace grass in small yard areas. Each plant spreads to about one foot in diameter. Pollinators love this plant's tiny yet plentiful flowers.
- Lemon thyme (Thymus citriodorus) has intensely lemon-scented leaves on upright stems that can reach about a foot tall. Some varieties feature variegated leaves, making them extra showy as filler plants in window boxes and other containers. In the kitchen, lemon thyme makes a bright and flavorful addition to marinades and salads.
- Wooly thyme (Thymus pseudolanuginosus) is a creeping groundcover with fuzzy stems and leaves that form a dense, silvery mat that spreads about a foot in diameter. It is scent-free and rarely flowers. It also tolerates mild foot traffic when planted between paver stones on a walkway or garden steps.
Tips for Growing Thyme as a Perennial
Help your ornamental and culinary thyme plants thrive and live as long as possible with these essential care tips:
- Pinching seedlings of upright types when they are 2–3 inches tall yields a bushier plant and provides more foliage.
- Thyme does best in full sun and requires soil with excellent drainage. It will thrive in dry, rocky soil where other plants won’t.
- Like wine grapes, culinary thyme varieties develop the best flavor if the plant struggles a bit. Don’t overwater or overfertilize.
- If you grow thyme as a perennial, it may become woody and need to be divided every few years to encourage more fresh, new growth.