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When to Plant Sunflower in Worcester County, MD

Worcester County, Maryland Zone 7b May

May in the garden — Worcester County, Maryland

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

Avg. last frost April 12
Avg. first frost October 30
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 14.1 hrs
  1. Start sunflower under lights

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Worcester County, Maryland is in USDA Zone 7b. The average last spring frost is April 12 and the first fall frost is October 30, giving you a growing season of approximately 201 days.

At an elevation of 633 feet, Worcester County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Sunflower during the growing season.

Worcester County, MD (Zone 7b) Long season
201 days
Last Spring Frost April 12
201 growing days
First Fall Frost October 30
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Worcester County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (68 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 28 – Aug 16
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: Feb 22 Transplant: Apr 26 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 11 Transplant: May 13 🍅 Harvest: Jul 22 – Sep 9

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 Worcester County

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

Soil pH

Your soil pH (5.7–6.5) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Sunflower prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 201-day season

Sow every 8 weeks. Last sowing by Jul 22 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sunflower

Sunflower needs approximately 0.5 inches of water per week (2.2" 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 2.6" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 3.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.5" 0" ✅ Rainfall sufficient
Aug 2.2" 4.1" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 2.6" 0" ❄️ Dormant

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

Sunflower 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.

Sunflower needs ~1,551 GDD — county provides 3,668 GDD Excellent fit

Sunflower Planting Timeline — Worcester County, MD

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 19 Apr 19 – May 10
Harvest July 5 Jul 5 – Aug 23

Plant 1" deep · 18" apart · Rows 30" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

201 days in Worcester County

Growing Tips for Sunflower in Worcester County

Direct sow Sunflower outdoors after April 12 in Worcester County when soil has warmed and frost danger has passed.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Worcester County, MD?

Worcester County is in Zone 7b with an average last frost of April 12. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Worcester County, MD?

Worcester County, Maryland is in USDA Hardiness Zone 7b. The average last spring frost is April 12 and first fall frost is October 30.

🌱

Your Worcester County Garden Planner — Free

A 24-page printable planner built for Worcester 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 Worcester County, MD. Local conditions may vary. Last updated: May 2026.

Sources & credits

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