The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 getting a good idea when you can plant calendula is to examine 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 moderately cold tolerant which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

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. Any later than that and your calendula may not have a chance to grow to maturity. 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 April 15 in Cambridge. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Cambridge may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Cambridge you get surprised by a frost after April 15 so always 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 6a.

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

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

Plants to Grow in Cambridge

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