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When to Plant Fennel in Coryell County, TX

Coryell County, Texas Zone 8b May

Your May game plan for Coryell County, Texas

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 16
Avg. first frost November 15
Soil temp (4") 63°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Sow fennel in trays indoors

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

To set up a strong June, finish these tasks
  • First harvests: fennel

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Florence fennel is grown for its swollen bulb-like stem base, which has a mild anise flavor. It is crisp raw in salads and sweet when roasted or braised.

Coryell County, Texas is in USDA Zone 8b. The average last spring frost is March 16 and the first fall frost is November 15, giving you a growing season of approximately 244 days.

At an elevation of 3,488 feet, Coryell County receives approximately 65 inches of rainfall annually with predominantly clay soil. Summer highs average 91°F, providing good warmth for Fennel during the growing season. Clay soil retains moisture well for Fennel, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel root diseases.

Coryell County, TX (Zone 8b) Long season
244 days
Last Spring Frost March 16
244 growing days
First Fall Frost November 15

Coryell County Soil Profile

Soil Type

Clay

Soil pH

7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: May 21 – Jul 2
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Jan 26 Transplant: Mar 30 🍅 Harvest: Jun 1 – Jul 13
Safe Start (90%) ✓ Fits season (117 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🍅 Harvest: Jun 26 – Aug 7

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 Coryell County

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

Soil pH

Your soil pH (7.0–8.3) is more alkaline than Fennel prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (41% clay) in Coryell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Fennel.

How to Plant Fennel

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

Succession Planting Fennel

4
successive plantings in your 244-day season

Sow every 6.9 weeks. Last sowing by Aug 17 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Fennel

Fennel needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Fennel Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.6" 3.8" 0" ✅ Rainfall sufficient
Apr 2.6" 6.9" 0" ✅ Rainfall sufficient
May 2.6" 9.1" 0" ✅ Rainfall sufficient
Jun 2.6" 9.5" 0" ✅ Rainfall sufficient
Jul 2.6" 9" 0" ✅ Rainfall sufficient
Aug 2.6" 7.2" 0" ✅ Rainfall sufficient
Sep 2.6" 7.1" 0" ✅ Rainfall sufficient
Oct 2.6" 4.6" 0" ✅ Rainfall sufficient
Nov 2.6" 2" 0.6" 💧 Light watering
Dec 1.7" 0" ❄️ Dormant

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

Fennel 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 needs ~1,369 GDD — county provides 4,453 GDD Excellent fit

Fennel Planting Timeline — Coryell County, TX

Fennel Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors March 30 Mar 30 – Apr 13
Direct Sow March 23 Mar 23 – Apr 13
Harvest June 1 Jun 1 – Jul 13

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

244 days in Coryell County

Growing Tips for Fennel in Coryell County

Direct sow Fennel outdoors after March 16 in Coryell County when soil has warmed and frost danger has passed.

With Coryell County's clay soil (41% clay), work in 3-4 inches of compost before planting Fennel. Avoid tilling when soil is wet to prevent compaction.

Common pests for Fennel 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 late summer for fall harvest to reduce bolting. Hill soil around bulbs as they enlarge. Harvest when bulbs are tennis-ball sized before they elongate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel in Coryell County, TX?

Coryell County is in Zone 8b with an average last frost of March 16. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coryell County, TX?

Coryell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 16 and first fall frost is November 15.

🌱

Your Coryell County Garden Planner — Free

A 24-page printable planner built for Coryell County (Zone 8b). 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 Coryell 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.