Thymes can be difficult to start from seed. Because the seeds are quite small, they are usually best scatter across a growing tray and gently pressed into the soil with no cover. Thyme needs light and warmth to germinate, so water the soil thoroughly, then cover the tray in plastic wrap and put it under a grow light or in a sunny window on a heat mat. Thyme can take up to 12 weeks to germinate, so be patient! Once the seedlings are just below the plastic wrap, remove it. When they are 4” tall, you can transplant them to your garden. Once your thyme is established (about 1 year), it can be divided for easier propagation.
Thymes are always at home in rock gardens, walls, and on rocky slopes. Many will meander down crevices, cascade over boulders, etc. Thymes blend well with other plants, too. Good drainage encourages a vigorous carpet of thyme. Native to the Mediterranean region, thymes prefer dry conditions and average garden soil. Too much water and heavy soil cause thymes to rot. A top dressing or mulch of sand or gravel helps to thwart frost-heaving of the plants in winter and diverts water away from the stems and leaves. In areas with high rainfall, planting thymes on rocky slopes helps alleviate drainage problems, but it is also important to select the right cultivar for your conditions.
Most thymes prefer full sun. Watering and fertilization are rarely necessary once plants have become established. In fact, dry conditions improve plant vigor, and poor soil increases aromatic oil production, making thymes more fragrant. Humidity is thyme’s chief enemy. Damage appears as tattered foliage and naked branches.
In winter, if your area gets especially cold (Zone 5 and lower), cover thyme to help it through the winter. If you add mulch to protect the roots, be sure to remove the mulch in spring.
To harvest thyme, just cut what is needed, no more than a third of the plant at a time. Harvesting in the morning gives the best flavor. Use thyme fresh or dry. Pinch the end of the stem and drag your fingers along the stem toward the base and the majority of the thyme leaves will fall off!