Blog

When to Plant Hyssop in Yellow Medicine County, MN

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.

Yellow Medicine County, Minnesota is in USDA Zone 4a. The average last spring frost is April 30 and the first fall frost is October 4, giving you a growing season of approximately 157 days.

At an elevation of 1,382 feet, Yellow Medicine County receives approximately 34 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Hyssop to ensure they mature before fall.

Yellow Medicine County, MN (Zone 4a) Moderate season
157 days
Last Spring Frost April 30
157 growing days
First Fall Frost October 4

Yellow Medicine County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Transplant: May 2 🍅 Harvest: Jul 11 – Sep 12
Recommended (50%) ✓ Fits season (17 days to spare)
Transplant: May 7 🍅 Harvest: Jul 16 – Sep 17
Safe Start (90%) ✓ Fits season (12 days to spare)
Transplant: May 22 🍅 Harvest: Jul 31 – Oct 2

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Hyssop needs ~920 GDD — county provides 1,805 GDD Excellent fit

Hyssop Planting Timeline โ€” Yellow Medicine County, MN

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 โ€“ May 21
Harvest July 16 Jul 16 โ€“ Sep 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
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 4a

Growing Season

157 days

Growing Tips for Yellow Medicine 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 Yellow Medicine County, MN?

Yellow Medicine County is in Zone 4a with an average last frost of April 30. Plan your Hyssop planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Yellow Medicine County, MN?

Yellow Medicine County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is April 30 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Yellow Medicine County gardeners in Zone 4a 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 Yellow Medicine County, MN. Local conditions may vary. Last updated: April 2026.