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When to Plant Fennel in Niagara, ON

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.

Niagara, Ontario is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 1, giving you a growing season of approximately 220 days.

At an elevation of 324 feet, Niagara receives approximately 46.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 92°F, providing good warmth for Fennel during the growing season. Clay soil retains moisture well for Fennel, but amend with compost to improve drainage and prevent root rot.

Niagara, ON (Zone 8a) Long season
220 days
Last Spring Frost March 26
220 growing days
First Fall Frost November 1

Niagara Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Monthly Watering Guide for Fennel

Fennel 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 Needs Rainfall You Supplement Action
Jan 2" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 4.3" 3.4" 0.9" 💧 Light watering
Apr 4.3" 4.1" 0.2" 💧 Light watering
May 4.3" 5.2" 0" ✅ Rainfall sufficient
Jun 4.3" 5.8" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 4.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

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

Fennel Planting Timeline — Niagara, ON

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow April 2 Apr 2 – Apr 23
Harvest June 11 Jun 11 – Jul 23

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

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 8a

📆 Growing Season

220 days in Niagara

Growing Tips for Niagara

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 →

Frequently Asked Questions

When should I plant Fennel in Niagara, ON?

Niagara is in Zone 8a with an average last frost of March 26. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Niagara, ON?

Niagara, Ontario is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 1.

🌱

Your Niagara Garden Planner — Free

A 22-page printable planner built for Niagara (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Niagara, ON. Local conditions may vary. Last updated: June 2026.

Sources & credits

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