Creeping thyme (Thymus serpyllum) offers an attractive, low-growing alternative to traditional turf grass, providing a dense, fragrant mat for ground cover. This perennial herb is known for its ability to withstand dry conditions once established, making it a sustainable choice for water-conscious landscapes. It spreads quickly, reaching a mature height of only one to four inches, and produces tiny pink or purple flowers in late spring and summer. Choosing creeping thyme means trading the high-maintenance demands of grass for an aromatic, drought-tolerant, and pollinator-friendly landscape.
Preparing the Site for Creeping Thyme
Successful establishment requires proper site selection and meticulous soil preparation. Creeping thyme needs a location that receives full sun, meaning a minimum of six to eight hours of direct sunlight daily, to ensure dense growth and abundant flowering. Planting in heavily shaded areas will cause the thyme to become leggy and sparse.
Excellent soil drainage is the most significant factor for long-term health, as the plant is highly susceptible to root rot in waterlogged conditions. Creeping thyme prefers dry, poor soils, including sandy, gritty, or rocky compositions, and typically does well in a neutral to slightly alkaline pH. Heavy clay soils should be amended with gritty material, such as coarse sand or fine gravel, along with compost to improve porosity and aeration.
Removing all existing turf and weeds is necessary before planting, as competition will choke out the slow-to-establish thyme. For large areas, effective clearing methods include solarization, which uses clear plastic sheeting, or the careful application of non-selective herbicides. Manual removal by digging or sod-cutting is also effective. Once cleared, the top one to two inches of soil should be loosened to facilitate root penetration.
Selecting the Best Planting Approach
Gardeners typically choose between sowing seeds or transplanting starter plants, often called plugs, for covering a large area. The decision involves weighing the initial cost against the time required for the area to fill in completely. Sowing seeds is the most economical approach for expansive areas, but it demands considerable patience and diligent weed management during the first year.
A creeping thyme lawn grown from seed is slow to establish, often taking two to three years to form a dense mat. Conversely, using starter plants, such as plugs, mats, or divisions, provides a significantly faster and more reliable outcome. Plugs are already rooted specimens, guaranteeing a higher rate of survival and quicker spread than seed germination. While the initial purchase price is higher, plugs reduce the overall establishment time and minimize early weeding labor.
Installation: Planting Seeds or Starter Plants
The physical installation process differs significantly depending on whether seeds or plugs are used. When planting plugs, space the small plants strategically to allow for even coverage as they mature. A general recommendation is to place the plugs between six and twelve inches apart; closer spacing yields faster, denser coverage.
To plant a plug, dig a hole slightly wider and only as deep as the root ball. Ensure the top of the root crown sits level with the surrounding soil surface. Gently tease out any tightly bound roots before setting the plant. After backfilling the soil, lightly tamp the area to remove air pockets and ensure firm contact between the roots and the soil.
If planting from seed, the timing is best in early spring after the danger of hard frost has passed, or in the fall, allowing six to eight weeks before the first hard frost. Thyme seeds require minimal soil cover to germinate successfully. For even distribution, mix the seeds with fine sand before broadcasting them thinly over the prepared soil surface. After scattering, lightly rake the area to ensure surface contact and then gently press the seeds into the soil without burying them deeply.
Essential Care During Establishment
The first growing season is when the thyme is most vulnerable. Newly planted plugs or seedlings need regular watering to encourage a strong root system. The soil should be kept evenly moist but never saturated until the plants show signs of active growth and are clearly rooted.
Once the thyme is established and begins to spread, usually after several months, the watering frequency must be reduced dramatically. Creeping thyme is drought-tolerant, meaning supplemental watering is rarely needed unless the area experiences prolonged extreme heat. Overwatering after establishment is a common mistake that can quickly lead to fungal diseases and root death.
Weeding is critical during the first year, as the slow-growing thyme cannot yet compete effectively against aggressive weeds. Consistent manual removal of competing vegetation is necessary until the thyme forms a dense, continuous mat, typically by the second or third year. An established thyme lawn rarely requires mowing, but a light trimming after the main flowering period can encourage denser growth and prevent the stems from becoming woody.