One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Cambridge you should be able to determine when it's possible to plant calliopsis.

Planting Calendar for Calliopsis

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

Since calliopsis are not cold tolerant it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

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. Any later than that and your calliopsis may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your calliopsis indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Cambridge. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Cambridge is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Cambridge last frost occurs after April 15 be ready to protect your calliopsis if you have 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.