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When to Plant Sunflower in Saline County, KS

Saline County, Kansas Zone 6b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Saline County, Kansas.

Avg. last frost April 15
Avg. first frost October 24
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
Before June arrives, get these ready
  • Starting indoors: sunflower

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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.

Saline 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 680 feet, Saline County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Sunflower during the growing season.

Saline County, KS (Zone 6b) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24
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Saline County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Feb 14 Transplant: Apr 25 🍅 Harvest: Jul 4 – Aug 22
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Feb 18 Transplant: Apr 29 🍅 Harvest: Jul 8 – Aug 26
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Jul 20 – Sep 7

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 Saline County

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

Soil pH

Your soil pH (6.8–7.7) overlaps with Sunflower's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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 192-day season

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 2.2" 2.7" 0" ✅ Rainfall sufficient
May 2.2" 3" 0" ✅ Rainfall sufficient
Jun 2.2" 4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.1" 0" ✅ Rainfall sufficient
Aug 2.2" 2.9" 0" ✅ Rainfall sufficient
Sep 2.2" 1.9" 0.3" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Saline 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 ~1,296 GDD — county provides 2,928 GDD Excellent fit

Sunflower Planting Timeline — Saline County, KS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest July 8 Jul 8 – Aug 26

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 6b

📆 Growing Season

192 days in Saline County

Growing Tips for Sunflower in Saline County

Direct sow Sunflower outdoors after April 15 in Saline 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.

Saline County receives only 23" of rain annually. Sunflower needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Saline County, KS?

Saline 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 Saline County, KS?

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

🌱

Your Saline County Garden Planner — Free

A 24-page printable planner built for Saline 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 Saline County, KS. 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.