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When to Plant Hydrangeas in Camden County, NJ

Camden County, New Jersey Zone 7b August

August to-do list for Camden County, New Jersey

A quick August briefing for Camden County, New Jersey gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 5
Avg. first frost November 12
Soil temp (4") 87°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for hydrangeas

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong September, finish these tasks
  • 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).

Camden County, New Jersey is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is November 12, giving you a growing season of approximately 221 days.

At an elevation of 561 feet, Camden County receives approximately 43.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Hydrangeas during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Camden County, NJ (Zone 7b) Long season
221 days
Last Spring Frost April 5
221 growing days
First Fall Frost November 12

Camden County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Hydrangeas Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Jan 13 Transplant: Mar 24 🌸 Bloom: Jun 2 – Sep 29
Recommended (50%) ✓ Fits season (32 days to spare)
Start indoors: Jan 25 Transplant: Apr 5 🌸 Bloom: Jun 14 – Oct 11
Safe Start (90%) ✓ Fits season (32 days to spare)
Start indoors: Feb 17 Transplant: Apr 28 🌸 Bloom: Jul 7 – Nov 3

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 Camden County

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

Soil pH

Your soil pH (5.0–6.4) overlaps with Hydrangeas's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). 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 333 gal / 100 sq ft

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 3.1" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.3" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 3.3" 1" 💧 Light watering
Dec 3.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Camden 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 ~2,010 GDD — county provides 3,701 GDD Excellent fit

Hydrangeas Planting Timeline — Camden County, NJ

Hydrangeas Planting Calendar

Activity When Date Range
Start Indoors January 25 Jan 25 – Feb 8
Transplant Outdoors April 5 Apr 5 – Apr 19
Bloom June 14 Jun 14 – Oct 11

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

221 days in Camden County

Growing Tips for Hydrangeas in Camden County

Direct sow Hydrangeas outdoors after April 05 in Camden County when soil has warmed and frost danger has passed.

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 Camden County, NJ?

Camden County is in Zone 7b with an average last frost of April 5. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Camden County, NJ?

Camden County, New Jersey is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is November 12.

🌱

Your Camden County Garden Planner — Free

A 22-page printable planner built for Camden County (Zone 7b). 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 Camden County, NJ. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.