Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of figuring out when to plant calendula is to look at the USDA zone info for Owatonna.

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 tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant calendula in Owatonna 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 calendula and expect a good harvest is probably August. If you wait any later than that and your calendula may not have a chance to fully mature. You can get started a few weeks earlier by starting your calendula indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Owatonna. It might get as low as -25°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Owatonna and it changes from year to year. Half of the time in Owatonna it frosts late in the year after May 15 so make sure that you are prepared to protect your calendula if you have a surprise late frost.

USDA Zone Info for Owatonna

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Owatonna

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