When to Plant Thyme
Thyme is a hardy perennial herb. It can take a hard frost.
Start seeds indoors 8 to 10 weeks before the last spring frost, and plant out from the last frost to 3 weeks after it. The first harvest comes about 60 to 90 days after transplanting.
Example dates
The same rules in dates for three climates, using typical frost dates. Enter your ZIP code above for the dates where you live.
| Task | Last frost Mar 15first Nov 15 | Last frost Apr 15first Oct 25 | Last frost May 15first Sep 30 |
|---|---|---|---|
| Start seeds indoors | Jan 4 – 18 | Feb 4 – 18 | Mar 6 – 20 |
| Harden off | Mar 8 – 14 | Apr 8 – 14 | May 8 – 14 |
| Plant out | Mar 15 – Apr 5 | Apr 15 – May 6 | May 15 – Jun 5 |
| Harvest | May 14 – Oct 1 | Jun 14 – Nov 1 | Jul 14 – Dec 1 |
Growing thyme
Give thyme full sun and sharp drainage; trim lightly after flowering and replace woody plants every few years.
- Spacing: 12 in apart, in rows 18 in apart. In a raised bed, 1 per sq ft at square-foot spacing.
- Days to harvest: 60 to 90 from transplanting, then about 20 weeks of picking.
- Traditional companions: broccoli, brussels sprouts, cabbage, cauliflower, cherry tomato, collards, eggplant, kale, kohlrabi, strawberry, tomato. See companion plants for thyme.
Plan your beds with these dates
Draw your beds, tap squares to plant thyme and everything else, and get every crop's dates for your ZIP code in one calendar. Free, in your browser.
Open the garden plannerQuestions
When do I start thyme indoors?
8 to 10 weeks before the last spring frost: with a last frost of April 15, that's Feb 4 – 18. Enter your ZIP code above for your own dates.
Can thyme go in before the last frost?
No. Thyme is best planted once the frosts are over: plant it out from the last spring frost to 3 weeks after it.
How long does thyme take to grow?
About 60 to 90 days from transplanting to the first harvest, which then lasts about 20 weeks. Varieties differ: check the seed packet.
More planting dates
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (annual/seasonal, by station: freeze dates at 32 °F)
- Iowa State: Growing, Harvesting, and Drying Herbs
- University of California Cooperative Extension Master Gardeners (UC ANR): Use and Culture of Culinary Herbs (table from the California Master Gardener Handbook)
- Texas AgriLife Extension Service, Texas A&M System (J. Masabni): Growing Herbs (E-561, 2009)
- University of Illinois Extension: Start herb seeds indoors (news release, 2020)
- Oregon State University Extension Service: Herbs and Flowers in the Vegetable Garden
- Utah State University Extension, Utah 4-H: Creating Sustainable School and Home Gardens: Companion Planting (2025)
- Penn State Extension: Herbs Make Good Plant Partners and Companions
- SDSU Extension: Square-Foot Garden Sample Planting Layout (P-00379, 2026)
- University of Arizona Cooperative Extension, Yavapai County: The Art of Companion Planting (Master Gardener presentation, 2023)