When to plant Fennel in Saint Augustine, FL
Plant Fennel in Saint Augustine after February 9; the prime window is February 9–March 2.
When to Plant Fennel in Saint Augustine, FL
June in St. Johns County, Florida — your action list
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Bring in the fennel
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
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.
Saint Augustine, Florida is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.
At an elevation of 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Fennel may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.
Saint Augustine Soil Profile
Soil Type
Sand
Soil pH
4.9-6.1
Drainage
Well Drained
Fennel 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 Saint Augustine
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (4.9–6.1) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
Sandy soil in St. Johns County warms quickly in spring but drains fast. Fennel will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (1.5%). Add 2-3 inches of compost before planting Fennel.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Sep 03 to harvest before frost.
Fennel Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 2.4" | 0" | ❄️ Dormant |
| Feb | 2.6" | 2.4" | 0.2" | 💧 Light watering |
| Mar | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 7.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 6.9" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 2.1" | 0.5" | 💧 Light watering |
| Dec | 2.6" | 2.3" | 0.3" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. Johns 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 — Saint Augustine, FL
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 29 | Dec 29 – Jan 12 |
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Direct Sow | February 9 | Feb 9 – Mar 2 |
| Harvest | April 20 | Apr 20 – Jun 1 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
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 9b
📆 Growing Season
296 days in St. Johns County
Growing Tips for Fennel in Saint Augustine
Direct sow Fennel outdoors after February 09 in St. Johns County when soil has warmed and frost danger has passed.
Sandy soil in St. Johns County dries quickly — 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 99°F in St. Johns 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
Check more plant combinations with our Companion Planting Checker →
Fennel in Other Locations
When should I plant Fennel in Saint Augustine, FL?
In Saint Augustine, FL, plant Fennel after the last frost (around February 9) and before the first frost (around December 2). Best results when soil holds above 50°F.
What growing zone is Saint Augustine, FL for Fennel?
Saint Augustine sits in USDA Zone 9b. Fennel grows reliably in zones 4a through 10b, so it's a good fit here.
Can Fennel grow in Saint Augustine's climate?
Yes — Fennel grows well in Saint Augustine's temperate climate. Saint Augustine averages a 297-day frost-free season, with last frost around February 9 and first frost around December 2.
Your St. Johns County Garden Planner — Free
A 22-page printable planner built for St. Johns County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.