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When to plant Sunflower in Lyon County, KS

Plant Sunflower in Lyon County after April 12; the prime window is April 12–May 3.

When to Plant Sunflower in Lyon County, KS

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.

Lyon County, Kansas is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 629 feet, Lyon County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Lyon County, KS (Zone 6b) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Lyon County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Monthly Watering Guide for Sunflower

Sunflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan 0.7" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 2.8" 1.5" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.3" 2" 💧 Light watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Lyon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunflower Planting Timeline — Lyon County, KS

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow April 12 Apr 12 – May 3
Bloom July 5 Jul 5 – Oct 4

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

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

196 days in Lyon County

Growing Tips for Lyon County

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 Lyon County, KS?

Lyon County is in Zone 6b with an average last frost of April 12. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lyon County, KS?

Lyon County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 25.

When should I plant Sunflower in Lyon County, KS?

In Lyon County, KS, plant Sunflower after the last frost (around April 12) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Lyon County, KS for Sunflower?

Lyon 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 Lyon County's climate?

Yes — Sunflower grows well in Lyon County's temperate climate. Lyon County averages a 196-day frost-free season, with last frost around April 12 and first frost around October 25.

🌱

Your Lyon County Garden Planner — Free

A 22-page printable planner built for Lyon 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lyon County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

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