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When to plant Sunflower in Madera County, CA

Plant Sunflower in Madera County, when soil hits 50°F — usually March 28. Continue planting through April 18 for the spring crop.

When to Plant Sunflower in Madera County, CA

Madera County, California Zone 9a June

June in the garden — Madera County, California

Your garden in Madera County, California is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 18
Avg. first frost November 9
Soil temp (4") 87°F
Watering Critical
Pest pressure High
Daylight 14.5 hrs
  1. Bring in the sunflower

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Looking ahead to July
  • First harvests: sunflower

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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.

Madera County, California is in USDA Zone 9a. The average last spring frost is April 18 and the first fall frost is November 9, giving you a growing season of approximately 205 days.

At an elevation of 187 feet, Madera County receives approximately 14.5 inches of rainfall annually with predominantly loam soil. Summer highs average 104°F, so Sunflower may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Sunflower successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Madera County, CA (Zone 9a) Long season
205 days
Last Spring Frost April 18
205 growing days
First Fall Frost November 9

Madera County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Mar 3 Transplant: Mar 3 🌸 Bloom: May 26 – Oct 27
Recommended (50%) ✗ May not fit
Start indoors: Mar 28 Transplant: Mar 28 🌸 Bloom: Jun 20 – Nov 21
Safe Start (90%) ✗ May not fit
Start indoors: Apr 27 Transplant: Apr 27 🌸 Bloom: Jul 20 – Dec 21

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 Madera County

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

Soil pH

Your soil pH (6.2–7.8) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Sunflower

3
successive plantings in your 205-day season

Sow every 8 weeks. Last sowing by Aug 01 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 444 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 2.6" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 2.2" 1.3" 0.9" 💧 Light watering
May 2.2" 0.4" 1.8" 🚿 Regular watering
Jun 2.2" 0.1" 2.1" 🚿 Regular watering
Jul 2.2" 0" 2.2" 🚿 Regular watering
Aug 2.2" 0" 2.2" 🚿 Regular watering
Sep 2.2" 0.1" 2.1" 🚿 Regular watering
Oct 2.2" 0.7" 1.5" 🚿 Regular watering
Nov 2.2" 1.4" 0.8" 💧 Light watering
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Madera 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 ~2,380 GDD — county provides 5,740 GDD Excellent fit

Sunflower Planting Timeline — Madera County, CA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors March 28 Mar 28 – Apr 11
Direct Sow March 28 Mar 28 – Apr 18
Bloom June 20 Jun 20 – Nov 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

205 days in Madera County

Growing Tips for Sunflower in Madera County

Direct sow Sunflower outdoors after April 18 in Madera County when soil has warmed and frost danger has passed.

With summer highs reaching 104°F in Madera County, provide afternoon shade for Sunflower and water deeply in the morning.

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

Madera County receives only 14" of rain annually. Sunflower needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Madera County, CA?

Madera County is in Zone 9a 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 Madera County, CA?

Madera County, California is in USDA Hardiness Zone 9a. The average last spring frost is April 18 and first fall frost is November 9.

When should I plant Sunflower in Madera County, CA?

In Madera County, CA, plant Sunflower after the last frost (around April 18) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Madera County, CA for Sunflower?

Madera County sits in USDA Zone 9a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Madera County's climate?

Yes — Sunflower grows well in Madera County's temperate climate. Madera County averages a 205-day frost-free season, with last frost around April 18 and first frost around November 9.

🌱

Your Madera County Garden Planner — Free

A 22-page printable planner built for Madera County (Zone 9a). 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 Madera County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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