The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when to plant calendula is to refer to the USDA zone info for Cambridge.

Planting Calendar for Calendula

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

Calendula are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than more sensitive plants.

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

Last Frost Date

On average the last frost has passed is on April 15 in Cambridge. In the coldest months of winter you can expect an average low temperature of 5°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Cambridge and it changes from year to year. Half of the time in Cambridge there is a last frost after April 15 so be sure to be ready to cover your calendula in the event of one of those late frosts.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Cambridge

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