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When to Plant Hyssop in Montgomery County, MO

Hyssop is a semi-evergreen perennial herb with intense blue flower spikes that attract bees and butterflies. It has a minty, slightly bitter flavor used in liqueurs and teas.

Montgomery County, Missouri is in USDA Zone 6a. The average last spring frost is April 10 and the first fall frost is October 26, giving you a growing season of approximately 199 days.

At an elevation of 911 feet, Montgomery County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Hyssop during the growing season.

Montgomery County, MO (Zone 6a) Moderate season
199 days
Last Spring Frost April 10
199 growing days
First Fall Frost October 26

Montgomery County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 11 🍅 Harvest: Jun 20 – Aug 22
Recommended (50%) ✓ Fits season (59 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 26 – Aug 28
Safe Start (90%) ✓ Fits season (58 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 9 – Sep 10

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
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Hyssop needs ~1,280 GDD — county provides 3,184 GDD Excellent fit

Hyssop Planting Timeline โ€” Montgomery County, MO

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Harvest June 26 Jun 26 โ€“ Aug 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 6a

Growing Season

199 days

Growing Tips for Montgomery County

Start seeds indoors or direct sow in spring. Prune back in early spring to encourage bushy growth. Hyssop is drought-tolerant once established and thrives in poor soil.

Companion Planting

Good Companions

Avoid Planting Near

  • Radish

Level Up Your Garden

Frequently Asked Questions

When should I plant Hyssop in Montgomery County, MO?

Montgomery County is in Zone 6a with an average last frost of April 10. Plan your Hyssop planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Montgomery County, MO?

Montgomery County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 10 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Montgomery County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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