One of the first steps you take when you are making a decision about your gardening schedule is find your 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 way of figuring out when it's a good idea to plant calendula is to examine the USDA zone info for Columbus.

Planting Calendar for Calendula

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

Calendula are moderately cold tolerant which tells us that you can plant them a little bit earlier than more sensitive plants.

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. You probably don't want to wait any later than that or else your calendula may not have a chance to fully mature. Starting your calendula indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Columbus the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Columbus may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Columbus you get surprised by a frost after April 15 so be sure to be ready to cover your calendula in the event of a late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Columbus

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