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When to Plant Geraniums in Cumberland County, NJ

Cumberland County, New Jersey Zone 7b June

Cumberland County, New Jersey gardeners: here's your June plan

Welcome to June in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 28
Avg. first frost November 12
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Sow geraniums in trays indoors

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. Start harvesting geraniums

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Coming up in July — start thinking about
  • First harvests: geraniums

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Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.

Cumberland County, New Jersey is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 12, giving you a growing season of approximately 229 days.

At an elevation of 425 feet, Cumberland County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Cumberland County, NJ (Zone 7b) Long season
229 days
Last Spring Frost March 28
229 growing days
First Fall Frost November 12

Cumberland County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Start indoors: Jan 12 Transplant: Mar 23 🌸 Bloom: Jun 1 – Oct 5
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Jan 17 Transplant: Mar 28 🌸 Bloom: Jun 6 – Oct 10
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Jan 29 Transplant: Apr 9 🌸 Bloom: Jun 18 – Oct 22

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 Cumberland County

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

Soil pH

Your soil pH (5.2–6.8) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Geraniums.

How to Plant Geraniums

0.1"
Planting Depth
12"
Between Plants
14"
Between Rows

Succession Planting Geraniums

3
successive plantings in your 229-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Geraniums 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 468 gal / 100 sq ft

Monthly Watering Guide for Geraniums

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

Month Geraniums Needs Rainfall You Supplement Action
Jan 3.4" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 4.3" 3.5" 0.8" 💧 Light watering
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 3.1" 1.2" 💧 Light watering
Dec 2.9" 0" ❄️ Dormant

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

Geraniums 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.

Geraniums needs ~1,742 GDD — county provides 4,694 GDD Excellent fit

Geraniums Planting Timeline — Cumberland County, NJ

Geraniums Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 28 Mar 28 – Apr 11
Bloom June 6 Jun 6 – Oct 10

Plant 0.1" deep · 12" apart · Rows 14" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

229 days in Cumberland County

Growing Tips for Geraniums in Cumberland County

Direct sow Geraniums outdoors after March 28 in Cumberland County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Geraniums in Cumberland County, NJ?

Cumberland County is in Zone 7b with an average last frost of March 28. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cumberland County, NJ?

Cumberland County, New Jersey is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 12.

🌱

Your Cumberland County Garden Planner — Free

A 22-page printable planner built for Cumberland 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Cumberland County, NJ. 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.