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When to plant Sunflower in Barnstable County, MA

For Barnstable County, gardeners: plant Sunflower April 18 through May 9 once soil reads 50°F.

When to Plant Sunflower in Barnstable County, MA

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Barnstable County, Massachusetts is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 518 feet, Barnstable County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Barnstable County, MA (Zone 7a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Barnstable County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Monthly Watering Guide for Sunflower

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

Month Sunflower Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4.9" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Sunflower Planting Timeline — Barnstable County, MA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 18 Apr 18 – May 9
Bloom July 11 Jul 11 – Oct 17

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

189 days in Barnstable County

Growing Tips for Barnstable County

Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Barnstable County, MA?

Barnstable County is in Zone 7a with an average last frost of April 18. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Barnstable County, MA?

Barnstable County, Massachusetts is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 24.

When should I plant Sunflower in Barnstable County, MA?

In Barnstable County, MA, plant Sunflower after the last frost (around April 18) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Barnstable County, MA for Sunflower?

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

Can Sunflower grow in Barnstable County's climate?

Yes — Sunflower grows well in Barnstable County's temperate climate. Barnstable County averages a 189-day frost-free season, with last frost around April 18 and first frost around October 24.

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Your Barnstable County Garden Planner — Free

A 22-page printable planner built for Barnstable 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 Barnstable County, MA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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