Thyme
Common Thyme, Garden Thyme, Lemon Thyme, English Thyme
Tough, drought-tolerant perennial for zones 4–9. Excellent drainage is essential — overwatering is the main killer. Trim after flowering to maintain compact, bushy form. Harvest sprigs throughout the growing season; flavor intensifies as the plant matures. Works beautifully in rock gardens and containers. Replace every 3–4 years.
- Germination
- 14–28 days
- Soil temperature
- 18–24 °C
- Harvest after sowing
- 90–110 days
- Spacing
- 20–30 cm
When to plant thyme
Start seeds indoors 8–10 weeks before your last spring frost, and plant out within 2 weeks after it.
Dashed line: typical last spring frost in zone 7 (Apr 5). Zone dates are averages; most of the UK is zone 8–9, central Europe 6–7 and the Baltics and Scandinavia 4–6. In the app, Tomatograph uses your garden's own frost dates.
How to grow thyme
- 1
Sow indoors
Press the tiny seed onto the surface of compost without covering it, 8–10 weeks before the last frost. Germination is slow, 14–28 days.
- 2
Plant out
Plant after the last frost in the sunniest, best-drained spot you have. Gravelly soil, rock gardens and pots all suit it.
- 3
Water sparingly
Wet roots kill more thyme than drought. Trim after flowering to keep plants compact.
- 4
Harvest
Snip sprigs through the season once plants are established, from about 90 days. Replace plants every 3–4 years.
Growing conditions
Light
Full sun
Water
Low water
Temperature
-12–32 °C
Frost tolerance
Frost-hardy — tolerates frost
Days to maturity
70–90 days
Ideal soil pH
7.5–8
How Tomatograph watches your thyme
Tomatograph checks your local forecast every morning and only speaks up when one of these applies to your garden.
- First frost within 14 daysReminder to mulch the roots before winter.
- 3 days at 35 °C or aboveHeat-wave alert while plants are flowering or fruiting: shade and water early.
- Humidity above 80% for 48 hoursCheck for root rot, which thrives in those conditions.
- Within a week of maturityHarvest-window reminder based on when you planted.
Thyme questions
- When should I plant thyme?
- Start seeds indoors 8–10 weeks before your last spring frost, and plant out within 2 weeks after it.
- How long do thyme seeds take to germinate?
- Usually 14–28 days at a soil temperature of 18–24 °C.
- How long until I can harvest thyme?
- About 90–110 days after sowing, depending on variety and weather.
- How far apart should I plant thyme?
- Allow 20–30 cm between plants.
- What grows well with thyme?
- Good neighbours include rosemary, sage, cabbage, strawberry.
Growing guide written by Tomatograph. Planting figures from openplantdb (CC0 1.0). Zone frost dates are averages from openplantdb (CC0 1.0).