Brussels sprouts
Vegetables · Start indoors, set out
Brussels sprouts planting dates
At usual odds in 2026: Mar 16 – May 18.
The guide's rule 6 weeks before last frost to 3 weeks after last frost.
Frost odds · chance of a freezing night after your spring date
The 2026 season
Start indoors Set out Frost risk
At all three odds
| Frost odds | Start indoors | Set out |
|---|---|---|
| Bold (1 in 2) | Jan 12 – Mar 30 | Mar 9 – May 11 |
| Usual (3 in 10) | Jan 19 – Apr 6 | Mar 16 – May 18 |
| Careful (1 in 10) | Jan 27 – Apr 14 | Mar 24 – May 26 |
- Days to first harvest
- 80-90 after transplanting
- How it goes in
- Start indoors, set out 6-8 weeks indoors to transplant size
- Frost
- Frost-hardy Takes light frost.
- Soil to germinate
- 65-75°F
Plan it in your Garden Book
The book checks your date against the window and tells you when the first harvest could come.
Plus Free Garden Books hold 8 plantings a season; Seed Clock Plus holds 120: $1.95/month or $19.50/year. Free during preview What Plus adds
Source: Montana State University Extension, MontGuide MT199308AG, "Can I Grow That Here? Vegetable Seed and Transplant Schedules for Garden or Container" (reviewed August 2013), read with NOAA 1991-2020 freeze odds for Cleveland Hopkins. Wording ours; how we read the guide.