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When to plant Hydrangeas in Bingham County County,

Bingham County County's short 123-day growing season means one Hydrangeas planting between June 4 and June 18. No fall crop in Zone 5b.

When to Plant Hydrangeas in Bingham County, ID

Bingham County, Idaho Zone 5b June

Your June game plan for Bingham County, Idaho

June is a pivotal month for Bingham County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 21
Avg. first frost September 21
Soil temp (4") 42°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. Harden off and plant hydrangeas

    Frost risk is low now in Bingham County, Idaho. If you've been covering beds overnight, you can stop.

Coming up in July — start thinking about
  • Starting indoors: 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).

Bingham County, Idaho is in USDA Zone 5b. The average last spring frost is May 21 and the first fall frost is September 21, giving you a growing season of approximately 123 days.

At an elevation of 8,345 feet, Bingham County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Hydrangeas during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Bingham County, ID (Zone 5b) Short season
123 days
Last Spring Frost May 21
123 growing days
First Fall Frost September 21
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Bingham 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: Mar 1 Transplant: May 24 🌸 Bloom: Aug 9 – Nov 1
Recommended (50%) ✗ May not fit
Start indoors: Mar 12 Transplant: Jun 4 🌸 Bloom: Aug 20 – Nov 12
Safe Start (90%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 30 🌸 Bloom: Sep 15 – Dec 8

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 Bingham 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 Bingham County is excellent for Hydrangeas — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). 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
0.2″/week
Watering frequency Only during dry spells
Season total 215 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 2.5" 1.8" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.3" 2" 💧 Light watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 2.4" 0" ❄️ Dormant
Nov 1.8" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bingham 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 ~1,740 GDD — county provides 1,783 GDD Good fit

Hydrangeas Planting Timeline — Bingham County, ID

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors June 4 Jun 4 – Jun 18
Bloom August 20 Aug 20 – Nov 12

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

123 days in Bingham County

Growing Tips for Hydrangeas in Bingham County

Direct sow Hydrangeas outdoors after May 21 in Bingham County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Bingham County is tight for Hydrangeas (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Bingham County receives only 24" 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 Bingham County, ID?

Bingham County is in Zone 5b with an average last frost of May 21. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bingham County, ID?

Bingham County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 21 and first fall frost is September 21.

When should I plant Hydrangeas in Bingham County County, ?

In Bingham County County, , plant Hydrangeas after the last frost (around May 21) and before the first frost (around September 21). Best results when soil holds above 50°F.

What growing zone is Bingham County County, for Hydrangeas?

Bingham County County sits in USDA Zone 5b. Hydrangeas grows reliably in zones 3a through 9a, so it's a good fit here.

Can Hydrangeas grow in Bingham County County's climate?

Yes — Hydrangeas grows well in Bingham County County's temperate climate. Bingham County County averages a 123-day frost-free season, with last frost around May 21 and first frost around September 21.

🌱

Your Bingham County Garden Planner — Free

A 22-page printable planner built for Bingham 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 Bingham County, ID. 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.