When to Plant Parsnip in St. Louis County, MO
Parsnips are a sweet, nutty root vegetable that develops best flavor after exposure to frost. They require a long growing season but reward patient gardeners.
St. Louis County, Missouri is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.
At an elevation of 895 feet, St. Louis County receives approximately 40.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Parsnip during the growing season.
St. Louis County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.6
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Parsnip Planting Timeline — St. Louis County, MO
Parsnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Fall Sowing | August 15 | Aug 15 – Aug 29 |
| Harvest | July 13 | Jul 13 – Aug 24 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
100–130 days
Soil pH
6 – 7
USDA Zone
Zone 6a
Growing Season
194 days
Growing Tips for St. Louis County
Use only fresh seed as parsnip seed viability declines rapidly. Sow directly in spring in deeply worked soil. Leave roots in the ground through winter for sweetest flavor.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Parsnip in Other Locations
Frequently Asked Questions
When should I plant Parsnip in St. Louis County, MO?
St. Louis County is in Zone 6a with an average last frost of April 13. Plan your Parsnip planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Louis County, MO?
St. Louis County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 24.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help St. Louis County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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