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When to plant Sunflower in Conception, MO

For Sunflower in Conception, the safe spring window opens around April 29 and closes around May 20. Last expected frost is April 22, first fall frost October 13, giving a 174-day growing season.

When to Plant Sunflower in Conception, MO

Nodaway County, Missouri Zone 5b July

July in the garden — Nodaway County, Missouri

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 22
Avg. first frost October 13
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. It's harvest week for sunflower

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

A few tasks this July that'll pay off in August
  • 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.

Conception, Missouri is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 13, giving you a growing season of approximately 174 days.

At an elevation of 950 feet, Nodaway County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sunflower to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Conception, MO (Zone 5b) Moderate season
174 days
Last Spring Frost April 22
174 growing days
First Fall Frost October 13

Conception Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Mar 25 Transplant: Apr 22 🌸 Bloom: Jul 15 – Sep 30
Recommended (50%) ✓ Fits season (6 days to spare)
Start indoors: Apr 1 Transplant: Apr 29 🌸 Bloom: Jul 22 – Oct 7
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: Apr 15 Transplant: May 13 🌸 Bloom: Aug 5 – Oct 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 Conception

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 Nodaway 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 (3.2%). Annual compost additions will help Sunflower.

How to Plant Sunflower

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

Succession Planting Sunflower

2
successive plantings in your 174-day season

Sow every 8 weeks. Last sowing by Jul 05 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/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 1.9" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 2.2" 4.4" 0" ✅ Rainfall sufficient
May 2.2" 4.8" 0" ✅ Rainfall sufficient
Jun 2.2" 5.3" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 4.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3.7" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Nodaway 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 ~1,041 GDD — county provides 2,131 GDD Excellent fit

Sunflower Planting Timeline — Conception, MO

Sunflower Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 – Apr 15
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 29 Apr 29 – May 20
Bloom July 22 Jul 22 – Oct 7

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

Month-by-Month Timeline

MonthActivities
January
February
March
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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Nodaway County

Growing Tips for Sunflower in Conception

Direct sow Sunflower outdoors after April 22 in Nodaway 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 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 →

When should I plant Sunflower in Conception, MO?

In Conception, MO, plant Sunflower after the last frost (around April 22) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Conception, MO for Sunflower?

Conception sits in USDA Zone 5b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Conception's climate?

Yes — Sunflower grows well in Conception's temperate climate. Conception averages a 174-day frost-free season, with last frost around April 22 and first frost around October 13.

🌱

Your Nodaway County Garden Planner — Free

A 22-page printable planner built for Nodaway County (Zone 5b). 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 Nodaway County, MO. Local conditions may vary. Last updated: July 2026.