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When to Plant Fennel in Harrison County, TX

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.

Harrison County, Texas is in USDA Zone 8a. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.

At an elevation of 168 feet, Harrison County receives approximately 63.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96ยฐF, so Fennel may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Fennel will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel root diseases.

Harrison County, TX (Zone 8a) Long season
246 days
Last Spring Frost March 13
246 growing days
First Fall Frost November 14

Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (125 days to spare)
Start indoors: Jan 15 Transplant: Mar 19 🍅 Harvest: May 21 – Jul 2
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: May 29 – Jul 10
Safe Start (90%) ✓ Fits season (120 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 2

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 Harrison County

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

Soil pH

Your soil pH (5.3โ€“6.8) overlaps with Fennel's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Fennel.

Organic Matter

Organic matter is low (1.8%). Add 2-3 inches of compost before planting Fennel.

How to Plant Fennel

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

Succession Planting Fennel

4
successive plantings in your 246-day season

Sow every 6.9 weeks. Last sowing by Aug 16 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

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 โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar 2.6" 4.4" 0" โœ… Rainfall sufficient
Apr 2.6" 6" 0" โœ… Rainfall sufficient
May 2.6" 9.7" 0" โœ… Rainfall sufficient
Jun 2.6" 11" 0" โœ… Rainfall sufficient
Jul 2.6" 7.9" 0" โœ… Rainfall sufficient
Aug 2.6" 7.3" 0" โœ… Rainfall sufficient
Sep 2.6" 6.3" 0" โœ… Rainfall sufficient
Oct 2.6" 4" 0" โœ… Rainfall sufficient
Nov 2.6" 2.3" 0.3" ๐Ÿ’ง Light watering
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Harrison County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,650 GDD — county provides 5,412 GDD Excellent fit

Fennel Planting Timeline โ€” Harrison County, TX

Fennel Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 โ€“ Feb 6
Transplant Outdoors March 27 Mar 27 โ€“ Apr 10
Direct Sow March 20 Mar 20 โ€“ Apr 10
Harvest May 29 May 29 โ€“ Jul 10

Plant 1" deep ยท 15" apart ยท 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 Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

246 days in Harrison County

Growing Tips for Fennel in Harrison County

Direct sow Fennel outdoors after March 13 in Harrison County when soil has warmed and frost danger has passed.

Sandy soil in Harrison County dries quickly โ€” mulch Fennel with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96ยฐF in Harrison County, provide afternoon shade for Fennel and water deeply in the morning.

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 Harrison County, TX?

Harrison County is in Zone 8a with an average last frost of March 13. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harrison County, TX?

Harrison County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 13 and first fall frost is November 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harrison County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

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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 Harrison County, TX. Local conditions may vary. Last updated: April 2026.