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.

A way of determining when you can plant calendula is to check out the USDA zone info for Blair.

Planting Calendar for Calendula

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

Calendula do ok in mild cold which tells us that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant calendula in Blair 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. Starting your calendula indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Blair. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Blair is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Blair you get a frost after April 15 be ready to cover your calendula in the event of a surprise late frost.

USDA Zone Info for Blair

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 Blair

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