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When to plant Fennel in Dover, DE

Dover sits in USDA Zone 7b. Plant Fennel between April 9 (after last frost on April 2) and April 30.

When to Plant Fennel in Dover, DE

Kent County, Delaware Zone 7b July

This month in Kent County, Delaware

July is a pivotal month for Kent County, Delaware gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 2
Avg. first frost November 4
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the fennel

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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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.

Dover, Delaware is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.

At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Fennel during the growing season.

Dover, DE (Zone 7b) Long season
216 days
Last Spring Frost April 2
216 growing days
First Fall Frost November 4

Dover Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Fennel Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Start indoors: Feb 7 Transplant: Apr 11 🍅 Harvest: Jun 13 – Jul 25
Recommended (50%) ✓ Fits season (97 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 30
Safe Start (90%) ✓ Fits season (92 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jul 4 – Aug 15

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 Dover

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

Soil pH

Your soil pH (5.8–6.8) is within Fennel's preferred range (5.5–7.0).

Soil Texture

The silt loam soil in Kent County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Fennel.

How to Plant Fennel

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

Succession Planting Fennel

4
successive plantings in your 216-day season

Sow every 6.9 weeks. Last sowing by Aug 06 to harvest before frost.

Fennel Water Budget

Plant needs
0.6″/week
Rainfall provides
0.9″/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 4" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 2.6" 4" 0" ✅ Rainfall sufficient
May 2.6" 4.6" 0" ✅ Rainfall sufficient
Jun 2.6" 3.9" 0" ✅ Rainfall sufficient
Jul 2.6" 5.6" 0" ✅ Rainfall sufficient
Aug 2.6" 4.9" 0" ✅ Rainfall sufficient
Sep 2.6" 3.7" 0" ✅ Rainfall sufficient
Oct 2.6" 4" 0" ✅ Rainfall sufficient
Nov 2.6" 3.5" 0" ✅ Rainfall sufficient
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Kent 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 needs ~1,200 GDD — county provides 3,456 GDD Excellent fit

Fennel Planting Timeline — Dover, DE

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 – Feb 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 9 Apr 9 – Apr 30
Harvest June 18 Jun 18 – Jul 30

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
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: ideal

🗺️ USDA Zone

Zone 7b

📆 Growing Season

216 days in Kent County

Growing Tips for Fennel in Dover

Direct sow Fennel outdoors after April 02 in Kent 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

  • Tomatoes
  • Peppers
  • Beans

Check more plant combinations with our Companion Planting Checker →

When should I plant Fennel in Dover, DE?

In Dover, DE, plant Fennel after the last frost (around April 2) and before the first frost (around November 4). Best results when soil holds above 50°F.

What growing zone is Dover, DE for Fennel?

Dover sits in USDA Zone 7b. Fennel grows reliably in zones 4a through 10b, so it's a good fit here.

Can Fennel grow in Dover's climate?

Yes — Fennel grows well in Dover's temperate climate. Dover averages a 216-day frost-free season, with last frost around April 2 and first frost around November 4.

🌱

Your Kent County Garden Planner — Free

A 22-page printable planner built for Kent County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Kent County, DE. Local conditions may vary. Last updated: July 2026.