One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of making a decision about when it's possible to plant onions is to consult the USDA zone info for Oklahoma City.

Planting Calendar for Onions

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

Since onions are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant onions in Oklahoma City 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. You probably don't want to wait any later than that or else your onions may not have a chance to fully mature. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Oklahoma City. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Oklahoma City is just an average the actual date of last frost changes from year to year. Since half of the time in Oklahoma City there is a last frost after April 15 be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Oklahoma City

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 Low	0°F
Highest Expected Low	5°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 Oklahoma City

You may be interested in your other planting guides for Oklahoma City.