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When to Plant Fennel in Concho County, TX

Concho County, Texas Zone 8a May

What to do in May

Your garden in Concho County, Texas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 25
Avg. first frost November 12
Soil temp (4") 63°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Fire up the seed-starting tray: fennel

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

Coming up in June — start thinking about
  • 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.

Concho County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 3,848 feet, Concho County receives approximately 58.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Fennel during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel root diseases.

Concho County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12

Concho County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (120 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: May 28 – Jul 9
Recommended (50%) ✓ Fits season (113 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jun 10 – Jul 22
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jun 29 – Aug 10

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 Concho County

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

Soil pH

Your soil pH (6.6–7.4) overlaps with Fennel's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.0%). 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 232-day season

Sow every 6.9 weeks. Last sowing by Aug 14 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 1.6" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 2.6" 3.4" 0" ✅ Rainfall sufficient
Apr 2.6" 6.8" 0" ✅ Rainfall sufficient
May 2.6" 8.9" 0" ✅ Rainfall sufficient
Jun 2.6" 9.3" 0" ✅ Rainfall sufficient
Jul 2.6" 6.8" 0" ✅ Rainfall sufficient
Aug 2.6" 6.5" 0" ✅ Rainfall sufficient
Sep 2.6" 5.4" 0" ✅ Rainfall sufficient
Oct 2.6" 3.6" 0" ✅ Rainfall sufficient
Nov 2.6" 2.2" 0.4" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Concho 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 ~1,481 GDD — county provides 4,582 GDD Excellent fit

Fennel Planting Timeline — Concho County, TX

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors April 8 Apr 8 – Apr 22
Direct Sow April 1 Apr 1 – Apr 22
Harvest June 10 Jun 10 – Jul 22

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
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: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

232 days in Concho County

Growing Tips for Fennel in Concho County

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

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 Concho County, TX?

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

What planting zone is Concho County, TX?

Concho County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

🌱

Your Concho County Garden Planner — Free

A 24-page printable planner built for Concho 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 Concho 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.