When to Plant Fennel in Frio County, TX
Your May planting checklist for Frio County, Texas
Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.
-
It's harvest week for fennel
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June will be here before you know it — start on
- First harvests: fennel
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.
Frio County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.
At an elevation of 3,892 feet, Frio County receives approximately 51 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.
Frio County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Frio County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (6.4–7.2) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Frio County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Fennel.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Fennel.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Aug 28 to harvest before frost.
Plant Water Budget
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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | 2.6" | 1.9" | 0.7" | 💧 Light watering |
| Mar | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 4.9" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 7.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 9.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 6.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 5.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 4.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 1.6" | 1" | 💧 Light watering |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Frio 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 Planting Timeline — Frio County, TX
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 15 | Jan 15 – Jan 29 |
| Transplant Outdoors | March 5 | Mar 5 – Mar 19 |
| Direct Sow | February 26 | Feb 26 – Mar 19 |
| Harvest | May 7 | May 7 – Jun 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| 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 9a
📆 Growing Season
273 days in Frio County
Growing Tips for Fennel in Frio County
Direct sow Fennel outdoors after February 26 in Frio 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
Check more plant combinations with our Companion Planting Checker →
Fennel in Other Locations
Frequently Asked Questions
When should I plant Fennel in Frio County, TX?
Frio County is in Zone 9a with an average last frost of February 26. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Frio County, TX?
Frio County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.
Your Frio County Garden Planner — Free
A 24-page printable planner built for Frio 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.