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When to plant Geraniums in Chartley, MA

Chartley sits in cold Zone 7a. Plant Geraniums April 26–May 10 for the single annual harvest; the October 17 first frost closes the window.

When to Plant Geraniums in Chartley, MA

Bristol County, Massachusetts Zone 7a June

This month in Bristol County, Massachusetts

Your Bristol County, Massachusetts garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 26
Avg. first frost October 17
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 15 hrs
July will be here before you know it — start on
  • Starting indoors: geraniums
  • 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.

Chartley, Massachusetts is in USDA Zone 7a. The average last spring frost is April 26 and the first fall frost is October 17, giving you a growing season of approximately 174 days.

At an elevation of 833 feet, Bristol County receives approximately 47.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Geraniums during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Chartley, MA (Zone 7a) Moderate season
174 days
Last Spring Frost April 26
174 growing days
First Fall Frost October 17

Chartley Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.7

Drainage

Well Drained

Geraniums Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 8 Transplant: Apr 19 🌸 Bloom: Jun 28 – Oct 18
Recommended (50%) ✗ May not fit
Start indoors: Feb 15 Transplant: Apr 26 🌸 Bloom: Jul 5 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Mar 5 Transplant: May 14 🌸 Bloom: Jul 23 – Nov 12

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 Chartley

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

Soil pH

Your soil pH (5.1–6.7) is more acidic than Geraniums prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bristol 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

2
successive plantings in your 174-day season

Sow every 8 weeks. Last sowing by Jul 09 to harvest before frost.

Geraniums Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3.8" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 4.3" 4.4" 0" ✅ Rainfall sufficient
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bristol 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 ~1,424 GDD — county provides 2,914 GDD Excellent fit

Geraniums Planting Timeline — Chartley, MA

Geraniums Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 26 Apr 26 – May 10
Bloom July 5 Jul 5 – Oct 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

174 days in Bristol County

Growing Tips for Geraniums in Chartley

Direct sow Geraniums outdoors after April 26 in Bristol 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 →

When should I plant Geraniums in Chartley, MA?

In Chartley, MA, plant Geraniums after the last frost (around April 26) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Chartley, MA for Geraniums?

Chartley sits in USDA Zone 7a. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.

Can Geraniums grow in Chartley's climate?

Yes — Geraniums grows well in Chartley's temperate climate. Chartley averages a 174-day frost-free season, with last frost around April 26 and first frost around October 17.

🌱

Your Bristol County Garden Planner — Free

A 22-page printable planner built for Bristol County (Zone 7a). 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 Bristol County, MA. Local conditions may vary. Last updated: June 2026.