Before planting it is a good idea to find your USDA Zone info to figure out 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.

In Harvard you can figure out when it's a good idea to plant calendula 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 do well in some cold which means that you can plant them just a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant calendula in Harvard 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 really do well. If you are starting your calendula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Harvard. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Harvard is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Harvard there is a last frost after April 15 be ready to cover your calendula if you have one of those late frosts.

USDA Zone Info for Harvard

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 Harvard

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