When to Plant Fennel in Washington County, MD
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.
Washington County, Maryland is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 23, giving you a growing season of approximately 190 days.
At an elevation of 1,022 feet, Washington County receives approximately 45.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Fennel during the growing season.
Washington County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.8
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 Washington County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (5.4–6.8) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Washington County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Fennel.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jul 25 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 | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 3" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 3.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 4" | 0" | ❄️ Dormant |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Washington 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 — Washington County, MD
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Harvest | July 2 | Jul 2 – Aug 13 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| 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 6b
📆 Growing Season
190 days in Washington County
Growing Tips for Fennel in Washington County
Direct sow Fennel outdoors after April 16 in Washington 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 Washington County, MD?
Washington County is in Zone 6b with an average last frost of April 16. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, MD?
Washington County, Maryland is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 23.
Plan Your Garden with Confidence
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