When to Plant Onions in Zone 1b

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Zone 1b should be used to figure out when it's a good idea to plant onions.


Planting Calendar for Onions

Frost tolerance for onions: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Onions tend to make it in pretty solid cold which tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Zone 1b is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably July. If you wait any later than that and your onions may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

In Zone 1b the average date of last frost happens on June 15. It might get as low as -55°F during the coldest months of winter.

Since the USDA zone info for Zone 1b is just an average the actual date of last frost is different every year. Half of the time in Zone 1b it frosts late in the year after June 15 so just be sure to be ready to cover your onions if you have a late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-55°F
Highest Expected Low-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.