When to Plant Welsh onion in Aurora, CO

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

You can determine when to plant welsh onion in Aurora by referring to the USDA zone info.


Planting Calendar for Welsh onion

Frost tolerance for welsh onion: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

You can plant welsh onion just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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

The earliest that you can plant welsh onion in Aurora is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant welsh onion and expect a good harvest is probably August. Any later than that and your welsh onion may not have a chance to really do well. If you are starting your welsh onion indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Aurora. In the coldest months of winter you can expect an average low temperature of -10°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 Aurora and it will vary from year to year. Half of the time in Aurora last frost occurs after April 15 so be sure to be ready to protect your welsh onion in the event of a surprise late frost.

USDA Zone Info for Aurora

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 Aurora

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