The USDA Zone info is a great tool for gardeners to help us estimate 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.

The earliest that you can plant calendula in Oklahoma City should be estimated by referring to the USDA zone info.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Calendula are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant calendula 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 calendula and expect a good harvest is probably September. If you wait any later than that and your calendula may not have a chance to fully mature. If you are starting your calendula indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Oklahoma City the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Oklahoma City and it changes from year to year. Half of the time in Oklahoma City last frost occurs after April 15 so just be sure to be ready to cover your calendula if you have a 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.