The ideal time for onion transplants to go in the ground is about 6 weeks prior to your last average frost. Onion transplants can withstand a light frost; hard freezes below 20 degrees for a substantial time period that will kill them. Most farmers already know their appropriate time to plant onion transplants, but we have provided some planting time guidance based off of USDA Hardiness Zones for your reference.

For shipping, we recommend you receive them about the time you are ready to plant. Onion plants can survive off of the stored carbohydrates in the bulbs for up to 6 weeks, but planting fresher plants is more ideal. If you need to hold your plants for a bit until you can plant because of weather or shipping delays, that is no problem as long as they kept dry.

 USDA Hardiness Zone Map

USDA Hardiness Zones

Planting Recommendation by Zone


Zone 1:  mid to late May
Zone 2:  mid to late May
Zone 3:  early to mid May
Zone 4:  mid to late April
Zone 5:  mid March to mid April
Zone 6:  mid February to mid March
Zone 7: late January to mid February
Zones 8-13: should plant short day varieties December – January.