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When to plant Hydrangeas in Huerfano County, CO

Plant Hydrangeas in Huerfano County, between May 19 and June 2 — the only viable window. Zone 6a's short season (141 frost-free days) rules out a fall crop.

When to Plant Hydrangeas in Huerfano County, CO

Huerfano County, Colorado Zone 6a June

June in Huerfano County, Colorado — your action list

Your garden in Huerfano County, Colorado is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 49°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
Coming up in July — start thinking about
  • Starting indoors: hydrangeas
  • First harvests: hydrangeas

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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).

Huerfano County, Colorado is in USDA Zone 6a. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 7,235 feet, Huerfano County receives approximately 15.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Hydrangeas to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Hydrangeas successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Huerfano County, CO (Zone 6a) Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30

Huerfano County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Hydrangeas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 27 Transplant: May 15 🌸 Bloom: Jul 24 – Oct 30
Recommended (50%) ✗ May not fit
Start indoors: Mar 3 Transplant: May 19 🌸 Bloom: Jul 28 – Nov 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 5 Transplant: Jun 21 🌸 Bloom: Aug 30 – Dec 6

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 Huerfano County

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

Soil pH

Your soil pH (6.3–7.7) is more alkaline than Hydrangeas prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Huerfano County is excellent for Hydrangeas — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Hydrangeas.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Hydrangeas.

How to Plant Hydrangeas

1"
Planting Depth
48"
Between Plants
60"
Between Rows

Hydrangeas Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,276 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hydrangeas

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

Month Hydrangeas Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 1.1" 3.2" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.8" 2.5" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Hydrangeas 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.

Hydrangeas needs ~1,470 GDD — county provides 1,727 GDD Good fit

Hydrangeas Planting Timeline — Huerfano County, CO

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors May 19 May 19 – Jun 2
Bloom July 28 Jul 28 – Nov 3

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 Bloom
August Bloom
September Bloom
October Bloom
November Bloom
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

141 days in Huerfano County

Growing Tips for Hydrangeas in Huerfano County

Direct sow Hydrangeas outdoors after May 12 in Huerfano County when soil has warmed and frost danger has passed.

Your 141.0-day growing season in Huerfano County is tight for Hydrangeas (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Huerfano County receives only 15" of rain annually. Hydrangeas needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Huerfano County, CO?

Huerfano County is in Zone 6a with an average last frost of May 12. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Huerfano County, CO?

Huerfano County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 12 and first fall frost is September 30.

When should I plant Hydrangeas in Huerfano County, CO?

In Huerfano County, CO, plant Hydrangeas after the last frost (around May 12) and before the first frost (around September 30). Best results when soil holds above 50°F.

What growing zone is Huerfano County, CO for Hydrangeas?

Huerfano County sits in USDA Zone 6a. Hydrangeas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hydrangeas grow in Huerfano County's climate?

Yes — Hydrangeas grows well in Huerfano County's temperate climate. Huerfano County averages a 141-day frost-free season, with last frost around May 12 and first frost around September 30.

🌱

Your Huerfano County Garden Planner — Free

A 22-page printable planner built for Huerfano County (Zone 6a). 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 Huerfano County, CO. 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.