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When to plant Haskaps in Mercer County, IL

In Mercer County, Haskaps is a single-season spring crop — there's no second fall window. Plant May 8–May 22 for an 730–1095-day harvest, finishing well before the October 15 first frost.

When to Plant Haskaps in Mercer County, IL

Haskaps (honeyberries) are extremely cold-hardy shrubs producing elongated blue berries with a complex blueberry-raspberry flavor. They fruit very early in the season.

Mercer County, Illinois is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 15, giving you a growing season of approximately 181 days.

At an elevation of 777 feet, Mercer County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Haskaps to ensure they mature before fall.

Mercer County, IL (Zone 5b) Moderate season
181 days
Last Spring Frost April 17
181 growing days
First Fall Frost October 15

Mercer County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Monthly Watering Guide for Haskaps

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

Month Haskaps Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Haskaps Planting Timeline — Mercer County, IL

Haskaps Planting Calendar

Activity When Date Range
Transplant Outdoors May 8 May 8 – May 22

· 48" apart · Rows 72" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

181 days in Mercer County

Growing Tips for Mercer County

Plant at least two different varieties for cross-pollination. Fruits ripen 2-3 weeks before strawberries. Protect from birds. Very low maintenance once established. Tolerates extreme cold.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Haskaps in Mercer County, IL?

Mercer County is in Zone 5b with an average last frost of April 17. Plan your Haskaps planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mercer County, IL?

Mercer County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 15.

When should I plant Haskaps in Mercer County, IL?

In Mercer County, IL, plant Haskaps after the last frost (around April 17) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Mercer County, IL for Haskaps?

Mercer County sits in USDA Zone 5b. Haskaps grows reliably in zones 2a through 7b, so it's a good fit here.

Can Haskaps grow in Mercer County's climate?

Yes — Haskaps grows well in Mercer County's temperate climate. Mercer County averages a 181-day frost-free season, with last frost around April 17 and first frost around October 15.

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Your Mercer County Garden Planner — Free

A 22-page printable planner built for Mercer County (Zone 5b). 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 Mercer County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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