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When to Plant Hyssop in Bryan County, OK

Bryan County, Oklahoma Zone 8a June

June in the garden — Bryan County, Oklahoma

A quick June briefing for Bryan County, Oklahoma gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 78°F
Watering Moderate
Pest pressure High
Daylight 14.3 hrs
  1. Start harvesting hyssop

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July will be here before you know it — start on
  • First harvests: hyssop

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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 8a. 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 90°F, providing good warmth for Hyssop during the growing season.

Bryan County, OK (Zone 8a) 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

Hyssop 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.

Soil Compatibility in Bryan County

How your county's soil matches Hyssop's growing requirements.

Soil pH

Your soil pH (6.2–7.1) is within Hyssop's preferred range (6.0–8.0).

Soil Texture

The loam soil in Bryan County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Hyssop.

How to Plant Hyssop

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Hyssop

3
successive plantings in your 231-day season

Sow every 8 weeks. Last sowing by Aug 13 to harvest before frost.

Hyssop 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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hyssop

Hyssop needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Hyssop Needs Rainfall You Supplement Action
Jan 0.5" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 2.2" 1.6" 0.6" 💧 Light watering
Apr 2.2" 2.3" 0" ✅ Rainfall sufficient
May 2.2" 3" 0" ✅ Rainfall sufficient
Jun 2.2" 3.6" 0" ✅ Rainfall sufficient
Jul 2.2" 2.8" 0" ✅ Rainfall sufficient
Aug 2.2" 2.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.4" 0" ✅ Rainfall sufficient
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 2.2" 0.8" 1.4" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Bryan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hyssop Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

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

Hyssop Planting Timeline — Bryan County, OK

Hyssop Planting Calendar

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

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

231 days in Bryan County

Growing Tips for Hyssop in Bryan County

Direct sow Hyssop outdoors after March 25 in Bryan County when soil has warmed and frost danger has passed.

Bryan County receives only 22" of rain annually. Hyssop needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyssop in Bryan County, OK?

Bryan County is in Zone 8a with an average last frost of March 25. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bryan County, OK?

Bryan County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 11.

🌱

Your Bryan County Garden Planner — Free

A 22-page printable planner built for Bryan County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.