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

Lamar County, Texas Zone 8a May

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

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

Avg. last frost March 15
Avg. first frost November 15
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Collect fennel (herb) at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this May that'll pay off in June
  • 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.

Lamar County, Texas is in USDA Zone 8a. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.

At an elevation of 95 feet, Lamar County receives approximately 59.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Fennel (herb) during the growing season. Sandy soil warms quickly in spring — great for early planting — but Fennel (herb) will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel (herb) root diseases.

Lamar County, TX (Zone 8a) Long season
245 days
Last Spring Frost March 15
245 growing days
First Fall Frost November 15
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Lamar County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: May 2 – Jul 11
Recommended (50%) ✓ Fits season (119 days to spare)
Start indoors: Feb 8 Transplant: Mar 8 🍅 Harvest: May 10 – Jul 19
Safe Start (90%) ✓ Fits season (109 days to spare)
Start indoors: Mar 5 Transplant: Apr 2 🍅 Harvest: Jun 4 – Aug 13

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 Lamar County

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

Soil pH

Your soil pH (5.8–6.8) is within Fennel (herb)'s preferred range (5.5–7.0).

Soil Texture

Sandy soil in Lamar County warms quickly in spring but drains fast. Fennel (herb) will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting 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 245-day season

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

For a dedicated fall crop, sow by Sep 06.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/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 2.1" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 6.8" 0" ✅ Rainfall sufficient
May 4.3" 8.8" 0" ✅ Rainfall sufficient
Jun 4.3" 9.7" 0" ✅ Rainfall sufficient
Jul 4.3" 8" 0" ✅ Rainfall sufficient
Aug 4.3" 7.1" 0" ✅ Rainfall sufficient
Sep 4.3" 5.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Lamar 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 ~1,369 GDD — county provides 4,471 GDD Excellent fit

Fennel (herb) Planting Timeline — Lamar County, TX

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 – Feb 22
Transplant Outdoors March 8 Mar 8 – Mar 22
Direct Sow March 1 Mar 1 – Mar 22
Harvest May 10 May 10 – Jul 19
Fall Sowing September 6 Sep 6 – Sep 20

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

245 days in Lamar County

Growing Tips for Fennel (herb) in Lamar County

Direct sow Fennel (herb) outdoors after March 15 in Lamar County when soil has warmed and frost danger has passed.

Sandy soil in Lamar County dries quickly — mulch Fennel (herb) with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Lamar County, TX?

Lamar County is in Zone 8a with an average last frost of March 15. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lamar County, TX?

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

🌱

Your Lamar County Garden Planner — Free

A 24-page printable planner built for Lamar 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 Lamar 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.