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When to plant Sunflower in Kent County, DE

Plant Sunflower in Kent County, when soil hits 50°F — usually April 2. Continue planting through April 23 for the spring crop.

When to Plant Sunflower in Kent County, DE

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.

Kent County, Delaware is in USDA Zone 7b. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.

At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Kent County, DE (Zone 7b) Long season
216 days
Last Spring Frost April 2
216 growing days
First Fall Frost November 4

Kent County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

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 4" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 3.5" 0.8" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

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

Sunflower Planting Timeline — Kent County, DE

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow April 2 Apr 2 – Apr 23
Bloom June 25 Jun 25 – Oct 15

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May
June Bloom
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 7b

📆 Growing Season

216 days in Kent County

Growing Tips for Kent 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 Kent County, DE?

Kent County is in Zone 7b with an average last frost of April 2. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kent County, DE?

Kent County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 2 and first fall frost is November 4.

When should I plant Sunflower in Kent County, DE?

In Kent County, DE, plant Sunflower after the last frost (around April 2) and before the first frost (around November 4). Best results when soil holds above 50°F.

What growing zone is Kent County, DE for Sunflower?

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

Can Sunflower grow in Kent County's climate?

Yes — Sunflower grows well in Kent County's temperate climate. Kent County averages a 216-day frost-free season, with last frost around April 2 and first frost around November 4.

🌱

Your Kent County Garden Planner — Free

A 22-page printable planner built for Kent 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 Kent County, DE. Local conditions may vary. Last updated: June 2026.

Sources & credits

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