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When to Plant Hydrangeas in McHenry County, ND

Hydrangeas (Hydrangea spp.) are among the most spectacular summer-blooming shrubs, with large mophead, lacecap, or panicle flower clusters lasting weeks in the garden and drying beautifully for arrangements. Native to Asia and North America alike, the genus spans several garden species with different hardiness and blooming habits. Panicle hydrangeas (H. paniculata, e.g., Limelight) are the most cold-hardy (Zone 3) and most reliable bloomers; smooth hydrangeas (H. arborescens, e.g., Annabelle) are equally tough. Bigleaf hydrangeas (H. macrophylla) are prized for blue/pink color-shifting blooms but require reliable snow cover or winter protection in Zones 5–6. Flower color in macrophylla types is determined by soil pH (acidic = blue, alkaline = pink).

McHenry County, North Dakota is in USDA Zone 4a. The average last spring frost is May 17 and the first fall frost is September 22, giving you a growing season of approximately 128 days.

At an elevation of 661 feet, McHenry County receives approximately 22.4 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Hydrangeas to ensure they mature before fall.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
McHenry County, ND (Zone 4a) Short season
128 days
Last Spring Frost May 17
128 growing days
First Fall Frost September 22

McHenry County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Hydrangeas Planting Timeline — McHenry County, ND

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 31 May 31 – Jun 14
Bloom August 23 Aug 23 – Oct 18

Plant 1" deep · 48" apart · Rows 60" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

128 days in McHenry County

Growing Tips for McHenry County

Plant container-grown specimens in spring or fall, spacing at least 3–5 feet apart to allow for mature shrub spread. Most hydrangeas prefer morning sun with afternoon shade, especially in Zones 7+. Keep consistently moist — the name derives from the Greek for water vessel. Prune panicle and smooth types in late winter/early spring (they bloom on new wood). Prune bigleaf types only lightly after bloom; cutting stems in fall removes next year's buds. In Zone 5–6, protect bigleaf varieties with burlap or wire cages filled with leaves over winter. Fall planting (Zones 5+) gives excellent root establishment before summer heat. Year 2+ plants reach full size and bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hydrangeas in McHenry County, ND?

McHenry County is in Zone 4a with an average last frost of May 17. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is McHenry County, ND?

McHenry County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 17 and first fall frost is September 22.

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Your McHenry County Garden Planner — Free

A 22-page printable planner built for McHenry 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 McHenry County, ND. Local conditions may vary. Last updated: July 2026.

Sources & credits

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