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When to plant Onion in Dickinson County, KS

Onion planted in Dickinson County between April 1 and April 22 matures in 90–120 days — well before the October 22 first frost. A second sowing from August 13 to August 27 extends the harvest into fall.

When to Plant Onion in Dickinson County, KS

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Dickinson County, Kansas is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 754 feet, Dickinson County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.

Dickinson County, KS (Zone 6b) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Dickinson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Monthly Watering Guide for Onion

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

Month Onion Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 2.9" 1.4" 💧 Light watering
Jun 4.3" 3.1" 1.2" 💧 Light watering
Jul 4.3" 2.6" 1.7" 💧 Light watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 0.7" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Onion Planting Timeline — Dickinson County, KS

Onion Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Harvest July 15 Jul 15 – Sep 2
Fall Sowing August 13 Aug 13 – Aug 27

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

190 days in Dickinson County

Growing Tips for Dickinson County

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Dickinson County, KS?

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

What planting zone is Dickinson County, KS?

Dickinson County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 22.

When should I plant Onion in Dickinson County, KS?

In Dickinson County, KS, plant Onion after the last frost (around April 15) and before the first frost (around October 22). Best results when soil holds above 50°F.

What growing zone is Dickinson County, KS for Onion?

Dickinson County sits in USDA Zone 6b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.

Can Onion grow in Dickinson County's climate?

Yes — Onion grows well in Dickinson County's temperate climate. Dickinson County averages a 190-day frost-free season, with last frost around April 15 and first frost around October 22.

🌱

Your Dickinson County Garden Planner — Free

A 22-page printable planner built for Dickinson 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 Dickinson County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

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