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When to Plant Fennel (herb) in Stephens County, TX

Stephens County, Texas Zone 8a May

Stephens County, Texas gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Stephens County, Texas.

Avg. last frost April 4
Avg. first frost November 10
Soil temp (4") 62°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Time to start fennel (herb) inside

    These need a head start before your last frost (April 4). Sow into cells now so you're ready to transplant in a few weeks.

  2. Harvest fennel (herb) as they ripen

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

Coming up in June — start thinking about
  • First harvests: fennel (herb)

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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.

Stephens County, Texas is in USDA Zone 8a. The average last spring frost is April 4 and the first fall frost is November 10, giving you a growing season of approximately 220 days.

At an elevation of 3,055 feet, Stephens County receives approximately 63.4 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Fennel (herb) during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel (herb) root diseases.

Stephens County, TX (Zone 8a) Long season
220 days
Last Spring Frost April 4
220 growing days
First Fall Frost November 10

Stephens County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (100 days to spare)
Start indoors: Feb 14 Transplant: Mar 14 🍅 Harvest: May 16 – Jul 25
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Feb 28 Transplant: Mar 28 🍅 Harvest: May 30 – Aug 8
Safe Start (90%) ✓ Fits season (94 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: Jun 11 – Aug 20

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 Stephens County

How your county's soil matches Fennel (herb)'s growing requirements.

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Fennel (herb) prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Stephens County is excellent for Fennel (herb) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). 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 220-day season

Sow every 6.9 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Sep 01.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.7" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 3.6" 0" ❄️ Dormant
Apr 4.3" 7.1" 0" ✅ Rainfall sufficient
May 4.3" 9.8" 0" ✅ Rainfall sufficient
Jun 4.3" 10.6" 0" ✅ Rainfall sufficient
Jul 4.3" 7.2" 0" ✅ Rainfall sufficient
Aug 4.3" 7.3" 0" ✅ Rainfall sufficient
Sep 4.3" 6.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Stephens County). Supplement amounts are based on average rainfall — 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" — 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.

Fennel (herb) needs ~1,425 GDD — county provides 4,180 GDD Excellent fit

Fennel (herb) Planting Timeline — Stephens County, TX

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors March 28 Mar 28 – Apr 11
Direct Sow March 21 Mar 21 – Apr 11
Harvest May 30 May 30 – Aug 8
Fall Sowing September 1 Sep 1 – Sep 15

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

220 days in Stephens County

Growing Tips for Fennel (herb) in Stephens County

Direct sow Fennel (herb) outdoors after April 04 in Stephens 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.

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 Stephens County, TX?

Stephens County is in Zone 8a with an average last frost of April 4. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stephens County, TX?

Stephens County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is April 4 and first fall frost is November 10.

🌱

Your Stephens County Garden Planner — Free

A 24-page printable planner built for Stephens 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 Stephens County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

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