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When to Plant Fennel (herb) in Burleigh County, ND

Burleigh County, North Dakota Zone 4a April

April in Burleigh County, North Dakota — your action list

April is a pivotal month for Burleigh County, North Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost September 27
Soil temp (4") 40°F
Watering High
Pest pressure Low
Daylight 13.4 hrs
A few tasks this April that'll pay off in May
  • Transplants going out: fennel (herb)
  • Direct-sowing: fennel (herb)

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Herb fennel is grown for its aromatic leaves, stalks, and seeds rather than a bulb. It has a strong anise flavor and its flowers attract beneficial insects.

Burleigh County, North Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 27, giving you a growing season of approximately 138 days.

At an elevation of 1,102 feet, Burleigh County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Fennel (herb) to ensure they mature before fall.

Burleigh County, ND (Zone 4a) Short season
138 days
Last Spring Frost May 12
138 growing days
First Fall Frost September 27
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Burleigh County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jul 2 – Sep 10
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jul 7 – Sep 15
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 21 – Sep 29

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 Burleigh County

How your county's soil matches Fennel (herb)'s growing requirements.

Soil pH

Your soil pH (6.7–7.3) overlaps with Fennel (herb)'s range (5.5–7.0), though not a perfect match.

Soil Texture

The loam soil in Burleigh County is excellent for Fennel (herb) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Fennel (herb).

How to Plant Fennel (herb)

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Fennel (herb)

2
successive plantings in your 138-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 05.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 438 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Fennel (herb)

Fennel (herb) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Fennel (herb) Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Burleigh County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Fennel (herb) 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 (herb) needs ~862 GDD — county provides 1,587 GDD Excellent fit

Fennel (herb) Planting Timeline — Burleigh County, ND

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors May 5 May 5 – May 19
Direct Sow May 5 May 5 – May 26
Harvest July 7 Jul 7 – Sep 15
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

138 days in Burleigh County

Growing Tips for Fennel (herb) in Burleigh County

Direct sow Fennel (herb) outdoors after May 12 in Burleigh County when soil has warmed and frost danger has passed.

Common pests for Fennel (herb) in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

Burleigh County receives only 23" of rain annually. Fennel (herb) needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in spring or fall. Unlike Florence fennel, herb fennel does not form a bulb. Harvest fronds as needed and seeds when they turn brown. Self-sows readily.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel (herb) in Burleigh County, ND?

Burleigh County is in Zone 4a with an average last frost of May 12. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Burleigh County, ND?

Burleigh County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 27.

🌱

Your Burleigh County Garden Planner — Free

A 24-page printable planner built for Burleigh County (Zone 4a). 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 Burleigh County, ND. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.