When to Plant Onions in Grand Junction, CO

One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Grand Junction you can determine when it's a good idea to plant onions by referring to the USDA zone info.


Planting Calendar for Onions

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

Onions are very cold tolerant which means that you can start planting them much earlier 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 Grand Junction is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably September. If you wait any later than that and your onions may not have a chance to really do well. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Grand Junction the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Grand Junction and it changes from year to year. Half of the time in Grand Junction you get surprised by a frost after April 15 so always be ready to cover your onions in the event of a late frost.

USDA Zone Info for Grand Junction

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Grand Junction

You may be interested in your other planting guides for Grand Junction.