What to plant in March in Wyoming
In Wyoming (WY), March sits about 9 weeks before the average last frost (May 20). The state averages 118 frost-free days a year (last frost May 20, first frost September 15; USDA zones 3a, 3b, 4a, 4b, 5a, 6a).
24 crops have a sowing or planting window this month - and 1 of those windows close during March.
Dates here come from Wyoming frost dates (last frost May 20, first frost Sep 15). For one crop in detail, see when to plant onion, eggplant or bell pepper in Wyoming.
Wyoming covers a very wide range of climates, so dates near you can be two weeks or more either side of these. Enter your ZIP code in the planting calendar for dates tuned to your town.
Wyoming: planting activity through the year
Last chance in March
Celeriac (start seeds indoors, by Mar 11)
Start seeds indoors in March (24)
Indoor sowings for transplants later. Six to eight weeks under lights is typical for tomatoes and peppers; onions and leeks need longer.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Celeriac | Start seeds indoors | Feb 25 – Mar 11 | Last chance - ends Mar 11 |
| Celery | Start seeds indoors | Mar 4 – Mar 18 | Mar 4 – Mar 18 |
| Leek | Start seeds indoors | Mar 4 – Mar 18 | Mar 4 – Mar 18 |
| Onion | Start seeds indoors | Mar 4 – Mar 18 | Mar 4 – Mar 18 |
| Rosemary | Start seeds indoors | Mar 4 – Mar 18 | Mar 4 – Mar 18 |
| Eggplant | Start seeds indoors | Mar 11 – Mar 25 | Mar 11 – Mar 25 |
| Parsley | Start seeds indoors | Mar 11 – Mar 25 | Mar 11 – Mar 25 |
| Shallot | Start seeds indoors | Mar 11 – Mar 25 | Mar 11 – Mar 25 |
| Bell Pepper | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Chili Pepper | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Ginger | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Green Onion / Scallion | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Mint | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Oregano | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Sage | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Tarragon | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Thyme | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Turmeric | Start seeds indoors | Mar 18 – Apr 1 | Opens Mar 18 |
| Ground Cherry | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
| Lemon Balm | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
| Shiso (Perilla) | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
| Sweet Marjoram | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
| Tomatillo | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
| Tomato | Start seeds indoors | Mar 25 – Apr 8 | Opens Mar 25 |
Planting dates for popular crops in Wyoming
Every crop has its own full-year dates for Wyoming: indoor start, transplant or direct sowing, and harvest.
Seed-starting season: March garden jobs in Wyoming
- Start 24 crops indoors this month, including celeriac, celery, leek, onion. Use a sterile mix and good light - see starting seeds indoors.
- 9 weeks until the average last frost (May 20). The seed-starting calculator works out each crop's exact sowing date from it.
- Keep seedlings from stretching: lights 2-3 inches above the leaves for 14-16 hours a day, and a fan or a daily brush of the hand across the tops.
- Prepare beds as soon as the soil crumbles instead of smearing when squeezed - working wet soil ruins its structure for the season.
USDA zone chart for Wyoming
Wyoming spans USDA zones 3a, 3b, 4a, 4b, 5a, 6a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Wyoming in March?
24 crops have a window in March: celeriac, celery, leek, onion, rosemary, eggplant, parsley, shallot, bell pepper, chili pepper and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Wyoming in March?
No - start seeds indoors runs Mar 25 – Apr 8 in Wyoming.
Is it too late to plant lettuce in Wyoming in March?
Not too late - it's actually a little early. In Wyoming the next lettuce window opens around April 15: start seeds indoors.
When is the first frost in Wyoming?
The statewide average first fall frost is around September 15 and the last spring frost around May 20. Wyoming covers a wide range of climates, so local dates can differ by two weeks or more - look yours up by ZIP code.
What should I start indoors in March in Wyoming?
Celeriac (Feb 25 – Mar 11), Celery (Mar 4 – Mar 18), Leek (Mar 4 – Mar 18), Onion (Mar 4 – Mar 18), Rosemary (Mar 4 – Mar 18), Eggplant (Mar 11 – Mar 25), Parsley (Mar 11 – Mar 25), Shallot (Mar 11 – Mar 25), Bell Pepper (Mar 18 – Apr 1), Chili Pepper (Mar 18 – Apr 1), Ginger (Mar 18 – Apr 1), Green Onion / Scallion (Mar 18 – Apr 1), Mint (Mar 18 – Apr 1), Oregano (Mar 18 – Apr 1), Sage (Mar 18 – Apr 1), Tarragon (Mar 18 – Apr 1), Thyme (Mar 18 – Apr 1), Turmeric (Mar 18 – Apr 1), Ground Cherry (Mar 25 – Apr 8), Lemon Balm (Mar 25 – Apr 8), Shiso (Perilla) (Mar 25 – Apr 8), Sweet Marjoram (Mar 25 – Apr 8), Tomatillo (Mar 25 – Apr 8), Tomato (Mar 25 – Apr 8).
What to plant in March in other states
Dates are computed from Wyoming’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.