When to Plant Onions in Glenwood Springs, CO

One of the first steps you take when you are determining 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.

You can figure out when it's a good idea to plant onions in Glenwood Springs 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 plant them a quite a bit earlier than other plants that might not handle 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 Glenwood Springs 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. Any later than that and your onions may not have a chance to really do well. You can get started a little bit earlier by starting your onions indoors.

Last Frost Date

On average the last frost is on April 15 in Glenwood Springs. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Glenwood Springs is an average the actual date of last frost will vary from year to year. Since half of the time in Glenwood Springs it frosts late in the year after April 15 be ready to protect your onions in the event of one of those late frosts.

USDA Zone Info for Glenwood Springs

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Glenwood Springs

You may be interested in your other planting guides for Glenwood Springs.