Blog

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

Polk County, Texas Zone 9a May

May in Polk County, Texas — your action list

We've pulled the most time-sensitive tasks for Polk County, Texas this May and put them front and centre. Tackle them in order.

Avg. last frost March 4
Avg. first frost November 23
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for fennel (herb)

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

June prep starts now
  • First harvests: fennel (herb)

Instant PDF download. No spam, unsubscribe any time.

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.

Polk County, Texas is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 23, giving you a growing season of approximately 264 days.

At an elevation of 292 feet, Polk County receives approximately 63 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Fennel (herb) may need afternoon shade and extra watering during peak heat. 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.

Polk County, TX (Zone 9a) Long season
264 days
Last Spring Frost March 4
264 growing days
First Fall Frost November 23

Polk County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Start indoors: Jan 22 Transplant: Feb 12 🍅 Harvest: Apr 16 – Jun 25
Recommended (50%) ✓ Fits season (138 days to spare)
Start indoors: Feb 4 Transplant: Feb 25 🍅 Harvest: Apr 29 – Jul 8
Safe Start (90%) ✓ Fits season (133 days to spare)
Start indoors: Feb 28 Transplant: Mar 21 🍅 Harvest: May 23 – Aug 1

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 Polk County

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

Soil pH

Your soil pH (5.2–6.6) overlaps with Fennel (herb)'s range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Fennel (herb).

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Fennel (herb).

How to Plant Fennel (herb)

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Fennel (herb)

5
successive plantings in your 264-day season

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

For a dedicated fall crop, sow by Sep 28.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 700 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 1.4" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 4.3" 4" 0.3" 💧 Light watering
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 8.5" 0" ✅ Rainfall sufficient
Jun 4.3" 11.4" 0" ✅ Rainfall sufficient
Jul 4.3" 7" 0" ✅ Rainfall sufficient
Aug 4.3" 7.9" 0" ✅ Rainfall sufficient
Sep 4.3" 6.5" 0" ✅ Rainfall sufficient
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Polk 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 ~1,650 GDD — county provides 5,808 GDD Excellent fit

Fennel (herb) Planting Timeline — Polk County, TX

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors February 25 Feb 25 – Mar 11
Direct Sow February 11 Feb 11 – Mar 4
Harvest April 29 Apr 29 – Jul 8
Fall Sowing September 28 Sep 28 – Oct 12

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

Month-by-Month Timeline

MonthActivities
January
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 Fall Sowing
November
December

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: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

264 days in Polk County

Growing Tips for Fennel (herb) in Polk County

Direct sow Fennel (herb) outdoors after March 04 in Polk County when soil has warmed and frost danger has passed.

Sandy soil in Polk 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.

With summer highs reaching 96°F in Polk County, provide afternoon shade for Fennel (herb) and water deeply in the morning.

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 Polk County, TX?

Polk County is in Zone 9a with an average last frost of March 4. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, TX?

Polk County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 23.

🌱

Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Polk 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.