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When to plant Hydrangeas in Decatur County County,

Decatur County County's short 160-day growing season means one Hydrangeas planting between May 7 and May 21. No fall crop in Zone 6a.

When to Plant Hydrangeas in Decatur County, KS

Decatur County, Kansas Zone 6a June

Decatur County, Kansas gardeners: here's your June plan

Welcome to June in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 30
Avg. first frost October 7
Soil temp (4") 70°F
Watering High
Pest pressure High
Daylight 14.8 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).

Decatur County, Kansas is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 840 feet, Decatur County receives approximately 30.6 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Hydrangeas during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Decatur County, KS (Zone 6a) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7
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Decatur County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Hydrangeas Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 15 Transplant: May 3 🌸 Bloom: Jul 12 – Oct 18
Recommended (50%) ✗ May not fit
Start indoors: Feb 19 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 22
Safe Start (90%) ✗ May not fit
Start indoors: Mar 4 Transplant: May 20 🌸 Bloom: Jul 29 – Nov 4

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 Decatur County

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Hydrangeas prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Decatur 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 (3.8%). 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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 849 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 2.2" 2.1" 💧 Light watering
Jul 4.3" 3.1" 1.2" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Decatur 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 ~1,830 GDD — county provides 2,440 GDD Excellent fit

Hydrangeas Planting Timeline — Decatur County, KS

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors May 7 May 7 – May 21
Bloom July 16 Jul 16 – Oct 22

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 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

160 days in Decatur County

Growing Tips for Hydrangeas in Decatur County

Direct sow Hydrangeas outdoors after April 30 in Decatur County when soil has warmed and frost danger has passed.

Your 160.0-day growing season in Decatur County is tight for Hydrangeas (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Decatur County, KS?

Decatur County is in Zone 6a with an average last frost of April 30. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Decatur County, KS?

Decatur County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 7.

When should I plant Hydrangeas in Decatur County County, ?

In Decatur County County, , plant Hydrangeas after the last frost (around April 30) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Decatur County County, for Hydrangeas?

Decatur County 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 Decatur County County's climate?

Yes — Hydrangeas grows well in Decatur County County's temperate climate. Decatur County County averages a 160-day frost-free season, with last frost around April 30 and first frost around October 7.

🌱

Your Decatur County Garden Planner — Free

A 22-page printable planner built for Decatur 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 Decatur County, KS. 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.