USDA hardiness zone lookup
Saint Charles (63301) — USDA Zone 6b
Saint Charles, Missouri · 184-day growing season
Frost dates and growing season for 63301
| USDA hardiness zone | Zone 6b |
|---|---|
| Average last spring frost | April 16 |
| Average first fall frost | October 17 |
| Growing season length | ~184 days |
| Temperature range (F) | -10 to 0°F |
| Temperature range (C) | -23 to -18°C |
These are 50%-probability averages modeled from this ZIP's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by April 16, but in a colder-than-average year it can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.
Growing season in Saint Charles
Saint Charles, Missouri sits in USDA Zone 6b, with roughly 184 frost-free days between an average last spring frost around April 16 and a first fall frost around October 17. That is a long season — succession-sow through summer and run a full fall crop; heat-sensitive greens still need spring/autumn timing.
What grows in Saint Charles
Saint Charles falls in USDA Zone 6b, which means the same hardiness constraints apply as the full Zone 6 guide. Vegetables, herbs, and fruit trees rated to Zone 6b (or hardier) will overwinter here in a typical year.
- Tomatoes (all types)
- Peppers, eggplant
- Squash, melons, cucumbers
- Beans, peas
- Sweet corn
- Apples, pears, peaches, plums
- Cherries, blueberries
- Asparagus, rhubarb
- Garlic (fall-planted)
- Strawberries
What to plant in Saint Charles this week
Saint Charles's last frost is around April 16. This is the spring transplant window — start tomatoes and peppers indoors if you haven't, and direct-sow cold-tolerant crops now.
- When to plant tomatoes in zone 6
- When to plant peppers in zone 6
- When to plant basil in zone 6
- When to plant bush beans in zone 6
- When to plant cucumbers in zone 6
Full planting calendar for Saint Charles
Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 6 averages:
- When to plant tomatoes in zone 6
- When to plant peppers in zone 6
- When to plant basil in zone 6
- When to plant garlic in zone 6
- When to plant lettuce in zone 6
- When to plant bush beans in zone 6
- When to plant cucumbers in zone 6
- When to plant summer squash in zone 6
- When to plant peas in zone 6
- When to plant carrots in zone 6
Local microclimate notes
Zone tables give you the average — but Saint Charlesgardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record (the last time you actually got frost damage) is more accurate than any national average.
Source and methodology
Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from this ZIP's USDA hardiness zone and regional NOAA 1991-2020 climate normals — they are zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations are drawn from US Cooperative Extension references and curated by the Growli editorial team. Last reviewed May 2026.
Nearby ZIP codes in Missouri
- 63101 — Saint Louis (Zone 7a)
- 64106 — Kansas City (Zone 6b)
- 65101 — Jefferson City (Zone 6b)
- 65801 — Springfield (Zone 7a)
- 63116 — Saint Louis (South) (Zone 7a)
- 63118 — Saint Louis (Benton Park) (Zone 7a)
- 63136 — Saint Louis (North County) (Zone 6b)
- 63367 — Lake Saint Louis (Zone 6b)
- 64111 — Kansas City (Midtown) (Zone 6b)
- 64118 — Kansas City (Northland) (Zone 6a)
- 64133 — Kansas City (Raytown area) (Zone 6b)
- 64801 — Joplin (Zone 7a)
- Browse all US ZIP codes by state