When to Plant Onions in Gypsum, CO

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Gypsum you can estimate 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 do well in cold which tells us that you can plant them a quite a bit earlier than other frost tender plants.

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 Gypsum 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. Starting your onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Gypsum. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Gypsum and it is different every year. Half of the time in Gypsum it frosts late in the year after April 15 so be sure to be ready to cover your onions if you have a surprise late frost.

USDA Zone Info for Gypsum

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Gypsum

You may be interested in your other planting guides for Gypsum.