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.

In Northfield you can figure out when to plant calendula by looking at 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.

You can plant calendula a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant calendula in Northfield 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. 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

On average all chance of frost has passed is on May 15 in Northfield. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Northfield and it will vary from year to year. Half of the time in Northfield you get a frost after May 15 so make sure that you are ready to protect your calendula in the event of one of those late frosts.

USDA Zone Info for Northfield

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 Northfield

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