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When to Plant Hyssop in Bryan County, OK

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.

Bryan County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 928 feet, Bryan County receives approximately 22.3 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Hyssop during the growing season.

Bryan County, OK (Zone 7b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

Bryan County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (96 days to spare)
Transplant: Mar 18 🍅 Harvest: May 27 – Jul 29
Recommended (50%) ✓ Fits season (91 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (89 days to spare)
Transplant: Apr 22 🍅 Harvest: Jul 1 – Sep 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
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 233 gal / 100 sq ft
Drought risk

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

Hyssop needs ~1,400 GDD — county provides 4,042 GDD Excellent fit

Hyssop Planting Timeline โ€” Bryan County, OK

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors April 1 Apr 1 โ€“ Apr 15
Harvest June 10 Jun 10 โ€“ Aug 12

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 โ€”
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 7b

Growing Season

231 days

Growing Tips for Bryan 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 Bryan County, OK?

Bryan County is in Zone 7b with an average last frost of March 25. Plan your Hyssop planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bryan County, OK?

Bryan County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 25 and first fall frost is November 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bryan County gardeners in Zone 7b 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 Bryan County, OK. Local conditions may vary. Last updated: April 2026.