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

Houston County, Texas Zone 8b May

May in Houston County, Texas — your action list

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

Avg. last frost March 2
Avg. first frost November 23
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for fennel (herb)

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

June prep starts now
  • 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.

Houston County, Texas is in USDA Zone 8b. The average last spring frost is March 2 and the first fall frost is November 23, giving you a growing season of approximately 266 days.

At an elevation of 379 feet, Houston County receives approximately 59.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°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.

Houston County, TX (Zone 8b) Long season
266 days
Last Spring Frost March 2
266 growing days
First Fall Frost November 23
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Houston County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Apr 14 – Jun 23
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Apr 27 – Jul 6
Safe Start (90%) ✓ Fits season (134 days to spare)
Start indoors: Feb 19 Transplant: Mar 19 🍅 Harvest: May 21 – Jul 30

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 Houston County

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

Soil pH

Your soil pH (5.8–6.7) is within Fennel (herb)'s preferred range (5.5–7.0).

Soil Texture

Sandy soil in Houston 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 (1.8%). 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)

5
successive plantings in your 266-day season

Sow every 6.9 weeks. Last sowing by Aug 25 to harvest before frost.

For a dedicated fall crop, sow by Sep 14.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 185 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 4.3" 4.2" 0.1" 💧 Light watering
Apr 4.3" 5.9" 0" ✅ Rainfall sufficient
May 4.3" 9.7" 0" ✅ Rainfall sufficient
Jun 4.3" 8.2" 0" ✅ Rainfall sufficient
Jul 4.3" 8.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.9" 0" ✅ Rainfall sufficient
Sep 4.3" 5.6" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Houston 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 ~1,538 GDD — county provides 5,453 GDD Excellent fit

Fennel (herb) Planting Timeline — Houston County, TX

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors February 23 Feb 23 – Mar 9
Direct Sow February 16 Feb 16 – Mar 9
Harvest April 27 Apr 27 – Jul 6
Fall Sowing September 14 Sep 14 – Sep 28

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
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 · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

266 days in Houston County

Growing Tips for Fennel (herb) in Houston County

Direct sow Fennel (herb) outdoors after March 02 in Houston County when soil has warmed and frost danger has passed.

Sandy soil in Houston 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 Houston County, TX?

Houston County is in Zone 8b with an average last frost of March 2. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Houston County, TX?

Houston County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 2 and first fall frost is November 23.

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Your Houston County Garden Planner — Free

A 24-page printable planner built for Houston 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 Houston 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.