Can You Grow Onion in Iowa?
US · USDA Zone 5a · zones 4a, 4b, 5a, 5b
Onions grow well here — plant sets or transplants in early spring for a summer harvest.
Plant zones
Iowa last frost
Iowa first frost
Days to harvest
When to plant Onions in Iowa
Start indoors
Transplant
Harvest
Dates are approximate, based on Iowa's average frost dates. Your exact yard may vary by microclimate.
About Onion
Onions are a staple crop that stores well and can be grown as sets transplants or from seed.
Growing from sets is easiest for beginners. Plant in early spring — onions are frost-tolerant. Day-length sensitive — choose short-day long-day or day-neutral varieties based on your latitude.
Gardening in Iowa
Iowa has a humid continental climate with cold winters and warm summers. Most of the state is Zone 5a-5b. Excellent for cool-season crops and hardy fruits.
Frequently asked questions
Can you grow Onion in Iowa?
Onions grow well here — plant sets or transplants in early spring for a summer harvest.
What zone is Iowa?
Iowa spans USDA Zone 5a (4a, 4b, 5a, 5b).
When do you plant Onions in Iowa?
Plant Onions around mid-April (start indoors Feb 17), harvest Jul 14 – Aug 13.