One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Columbus you will be able to estimate when it's possible to plant calendula.

Planting Calendar for Calendula

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

Calendula do well in moderate cold which means that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant calendula in Columbus 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 really do well. You can get started a couple of weeks earlier by starting your calendula indoors.

Last Frost Date

The average date of last frost is March 15 in Columbus. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Columbus is an average the actual date of last frost changes from year to year. Since half of the time in Columbus there is a last frost after March 15 be ready to protect your calendula in the event of one of those late frosts.

USDA Zone Info for Columbus

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Columbus

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