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Sunflower Planting Guide

May

How to handle sunflower in May

This page is about sunflower in general. For your zone's exact planting and harvest dates, pick your county below.

Sun full sun
Water low
Days to harvest 70–100
Plant depth 1″
Spacing 18″
  1. How to water sunflower

    Water deeply but infrequently. sunflower prefers to dry out between waterings — soggy soil causes more problems than thirst.

  2. Where to put sunflower

    sunflower wants at least 6 hours of direct sun. Less than that and you'll get leggy plants with weak yields.

  3. Check your local forecast before planting

    Your zone determines the exact week to plant sunflower. Pick your county below and we'll line everything up against your frost dates.

See when to plant sunflower where you live →

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.

Helianthus annuus · Vegetable · Asteraceae family · 70–100 days to maturity

Get Your Personalized Sunflower Planting Dates

Enter your ZIP code to see exact planting dates, soil compatibility, and growing tips specific to your county.

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Where Can You Grow Sunflower?

Sunflower Growing Regions

Click any state to see the Sunflower planting schedule for that location.

Planting Dates by Zone

Zone Start Indoors Direct Sow Transplant Harvest
Zone 2a Mar 28 Jun 13 Jun 20 Aug 29 – Oct 17
Zone 2b Mar 20 Jun 5 Jun 12 Aug 21 – Oct 9
Zone 3a Mar 13 May 29 Jun 5 Aug 14 – Oct 2
Zone 3b Mar 8 May 24 May 31 Aug 9 – Sep 27
Zone 4a Mar 4 May 20 May 27 Aug 5 – Sep 23
Zone 4b Feb 27 May 15 May 22 Jul 31 – Sep 18
Zone 5a Feb 28 May 2 May 9 Jul 18 – Sep 5
Zone 5b Feb 21 Apr 25 May 2 Jul 11 – Aug 29
Zone 6a Feb 13 Apr 17 Apr 24 Jul 3 – Aug 21
Zone 6b Feb 6 Apr 10 Apr 17 Jun 26 – Aug 14
Zone 7a Feb 4 Apr 1 Apr 8 Jun 17 – Aug 5
Zone 7b Jan 28 Mar 25 Apr 1 Jun 10 – Jul 29
Zone 8a Jan 18 Mar 15 Mar 22 May 31 – Jul 19
Zone 8b Jan 7 Mar 4 Mar 11 May 20 – Jul 8
Zone 9a Dec 30 Feb 10 Feb 17 Apr 28 – Jun 16
Zone 9b Dec 14 Jan 25 Feb 1 Apr 12 – May 31
Zone 10a Nov 20 Jan 1 Jan 8 Mar 19 – May 7
Zone 10b Nov 20 Jan 1 Jan 8 Mar 19 – May 7
Zone 11a Nov 20 Jan 1 Jan 8 Mar 19 – May 7
Zone 11b Nov 20 Jan 1 Jan 8 Mar 19 – May 7

How to Plant Sunflower

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

Drought tolerant — water only when soil is dry 2" deep.

🧪 Soil pH

6 – 7.5

Prefers neutral to slightly acidic soil — ideal for most garden beds.

🗺️ Hardiness Zones

Zone 2a – 11b

📅 Days to Maturity

70–100 days

Medium-season crop. Start early for best results in shorter seasons.

👪 Plant Family

Asteraceae

Rotate with other families yearly to prevent soil-borne diseases. Don't plant in the same spot where Asteraceae family crops grew last year.

Succession Planting Sunflower

Sunflower matures in just 70–100 days, making it ideal for succession planting. In a typical 180-day growing season, you can get up to 2 successive plantings by sowing every 8 weeks.

Your actual succession count depends on your local frost dates. Enter your ZIP code to get personalized succession planting dates for your area.

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Companion Planting for Sunflower

✅ Good Companions

❌ Keep Away From

Potatoes

Check more combinations with our Companion Planting Checker →

Growing Tips for Sunflower

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.

Saving Sunflower Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Reader favourite
Seed Saving & Storage Guide

Seed Saving & Storage Guide

$27 $157 value

Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.

  • 200 plants, step-by-step: life cycle, pollination type, isolation
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Sunflower by State

Frequently Asked Questions

How long does it take to grow Sunflower?

Sunflower (Helianthus annuus) takes 70 to 100 days from planting to harvest. Exact timing depends on your variety, growing conditions, and USDA zone.

What zones can Sunflower grow in?

Sunflower can be grown in USDA zones 2a through 11b. Use the planting calendar above to find the exact dates for your zone.

How much sun does Sunflower need?

Growing Sunflower requires Full Sun (6-8+ hours), Low — drought tolerant, and soil pH of 6 to 7.5.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. 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.