Blog

When to Plant Parsley in Knox County, MO

Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

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 83ยฐF, so choose short-season varieties of Parsley to ensure they mature before fall.

Knox County, MO (Zone 5b) Moderate season
183 days
Last Spring Frost April 17
183 growing days
First Fall Frost October 17

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 7 Transplant: Apr 4 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 13 Transplant: Apr 10 🍅 Harvest: Jun 12 – Aug 14
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Mar 29 Transplant: Apr 26 🍅 Harvest: Jun 28 – Aug 30

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

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 137 gal / 100 sq ft
Parsley needs ~858 GDD — county provides 2,241 GDD Excellent fit

Parsley Planting Timeline โ€” Knox County, MO

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 โ€“ Mar 27
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow April 3 Apr 3 โ€“ Apr 24
Fall Sowing August 8 Aug 8 โ€“ Aug 22
Harvest June 12 Jun 12 โ€“ Aug 14

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“80 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

183 days

Growing Tips for Knox County

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Level Up Your Garden

Frequently Asked Questions

When should I plant Parsley in Knox County, MO?

Knox County is in Zone 5b with an average last frost of April 17. Plan your Parsley planting based on this frost date โ€” 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.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Knox County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Knox County, MO. Local conditions may vary. Last updated: April 2026.