When to Plant Asparagus in Knox County, MO
Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.
Knox County, Missouri is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 17, giving you a growing season of approximately 183 days.
At an elevation of 997 feet, Knox County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Asparagus to ensure they mature before fall.
Knox County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.8
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
Asparagus Planting Timeline — Knox County, MO
Asparagus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 1 | May 1 – May 15 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
730–1095 days
Soil pH
6.5 – 7.5
USDA Zone
Zone 5b
Growing Season
183 days
Growing Tips for Knox County
Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Asparagus in Other Locations
Frequently Asked Questions
When should I plant Asparagus in Knox County, MO?
Knox County is in Zone 5b with an average last frost of April 17. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Knox County, MO?
Knox County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 17.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Knox County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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