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When to Plant Fennel (herb) in Bryan County, OK

Herb fennel is grown for its aromatic leaves, stalks, and seeds rather than a bulb. It has a strong anise flavor and its flowers attract beneficial insects.

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 Fennel (herb) 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 (110 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: May 6 – Jul 15
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Feb 18 Transplant: Mar 18 🍅 Harvest: May 20 – Jul 29
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Mar 11 Transplant: Apr 8 🍅 Harvest: Jun 10 – Aug 19

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 Fennel (herb)'s growing requirements.

Soil pH

Your soil pH (6.2โ€“7.1) overlaps with Fennel (herb)'s range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Bryan County is excellent for Fennel (herb) โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Fennel (herb)

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Fennel (herb)

4
successive plantings in your 231-day season

Sow every 6.9 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,467 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Fennel (herb)

Fennel (herb) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Fennel (herb) Needs Rainfall You Supplement Action
Jan โ€” 0.5" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Apr 4.3" 2.3" 2" ๐Ÿ’ง Light watering
May 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Jun 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jul 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Aug 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Nov 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Bryan County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Fennel (herb) 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" โ€” every day above 50ยฐF 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.

Fennel (herb) needs ~1,312 GDD — county provides 4,042 GDD Excellent fit

Fennel (herb) Planting Timeline โ€” Bryan County, OK

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 โ€“ Mar 4
Transplant Outdoors March 18 Mar 18 โ€“ Apr 1
Direct Sow March 11 Mar 11 โ€“ Apr 1
Harvest May 20 May 20 โ€“ Jul 29
Fall Sowing September 2 Sep 2 โ€“ Sep 16

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

231 days in Bryan County

Growing Tips for Fennel (herb) in Bryan County

Direct sow Fennel (herb) outdoors after March 25 in Bryan County when soil has warmed and frost danger has passed.

Common pests for Fennel (herb) in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

Bryan County receives only 22" of rain annually. Fennel (herb) needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in spring or fall. Unlike Florence fennel, herb fennel does not form a bulb. Harvest fronds as needed and seeds when they turn brown. Self-sows readily.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel (herb) in Bryan County, OK?

Bryan County is in Zone 7b with an average last frost of March 25. Plan your Fennel (herb) 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.