When to plant Onion sets

The planting dates depend on your average frost dates. Enter a ZIP code to get yours, or read the USDA table below.

Earliest safe spring planting dates: onion sets
Average last freezePlant
Jan 30Jan 1 – 15
Feb 8Jan 1 – 15
Feb 18Jan 1 – 15
Feb 28Jan 1 – Mar 1
Mar 10Jan 15 – Mar 10
Mar 20Feb 1 – Mar 20
Mar 30Feb 15 – Mar 20
Apr 10Mar 1 – Apr 1
Apr 20Mar 10 – Apr 1
Apr 30Mar 10 – Apr 10
May 10Apr 10 – May 1
May 20Apr 20 – May 15
May 30May 1 – 30
June 10May 10 – June 10
Latest safe fall planting dates: onion sets
Average first freezePlant by
Aug 30May 1 – June 1
Sept 10May 1 – June 10
Sept 20Generally spring-planted
Sept 30Generally spring-planted
Oct 10Generally spring-planted
Oct 20Generally spring-planted
Oct 30Not listed
Nov 10Oct 1 – Dec 1
Nov 20Nov 1 – Dec 31
Nov 30Nov 1 – Dec 31
Dec 10Nov 1 – Dec 31
Dec 20Nov 1 – Dec 31

Source: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. The bulletin scan.

Onion Sets by state