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When to plant Sunflower in Pratt County, KS

For Sunflower in Pratt County, the safe spring window opens around April 15 and closes around May 6. Last expected frost is April 15, first fall frost October 24, giving a 192-day growing season.

When to Plant Sunflower in Pratt County, KS

Pratt County, Kansas Zone 6b June

Your June gardening checklist

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

Avg. last frost April 15
Avg. first frost October 24
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
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.

Pratt County, Kansas is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 852 feet, Pratt County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Pratt County, KS (Zone 6b) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Pratt County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Sunflower Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Mar 19 Transplant: Apr 9 🌸 Bloom: Jul 2 – Oct 1
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 25 Transplant: Apr 15 🌸 Bloom: Jul 8 – Oct 7
Safe Start (90%) ✓ Fits season (20 days to spare)
Start indoors: Apr 7 Transplant: Apr 28 🌸 Bloom: Jul 21 – Oct 20

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 Pratt County

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

Soil pH

Your soil pH (6.7–7.6) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is moderate (3.3%). 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 192-day season

Sow every 8 weeks. Last sowing by Jul 16 to harvest before frost.

Sunflower Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 373 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 2.2" 1.9" 0.3" 💧 Light watering
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.8" 0" ✅ Rainfall sufficient
Jul 2.2" 2.9" 0" ✅ Rainfall sufficient
Aug 2.2" 2.2" 0" ✅ Rainfall sufficient
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 1.2" 1" 💧 Light watering
Nov 0.6" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Pratt 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 ~1,424 GDD — county provides 3,216 GDD Excellent fit

Sunflower Planting Timeline — Pratt County, KS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 15 Apr 15 – May 6
Bloom July 8 Jul 8 – Oct 7

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May 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 · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Pratt County

Growing Tips for Sunflower in Pratt County

Direct sow Sunflower outdoors after April 15 in Pratt 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.

Pratt County receives only 21" 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 Pratt County, KS?

Pratt County is in Zone 6b with an average last frost of April 15. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pratt County, KS?

Pratt County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 24.

When should I plant Sunflower in Pratt County, KS?

In Pratt County, KS, plant Sunflower after the last frost (around April 15) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Pratt County, KS for Sunflower?

Pratt County sits in USDA Zone 6b. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Pratt County's climate?

Yes — Sunflower grows well in Pratt County's temperate climate. Pratt County averages a 192-day frost-free season, with last frost around April 15 and first frost around October 24.

🌱

Your Pratt County Garden Planner — Free

A 22-page printable planner built for Pratt County (Zone 6b). 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 Pratt County, KS. 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.