The USDA Zone info is a great tool for gardeners to help us figure out 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.

In Cambridge you can figure out when it's possible to plant calliopsis by reviewing the USDA zone info.

Planting Calendar for Calliopsis

Frost tolerance for calliopsis:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant calliopsis until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant calliopsis in Cambridge is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to fully mature. Starting your calliopsis indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to 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 will vary from year to year. Since half of the time in Cambridge last frost occurs after April 15 be ready to cover your calliopsis in the event of a surprise late frost.

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.