Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when it's the best time to plant campanula by checking out the USDA zone info for Cambridge.

Planting Calendar for Campanula

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

Since campanula do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant campanula in Cambridge 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 campanula and expect a good harvest is probably August. Any later than that and your campanula may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your campanula indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Cambridge. In the coldest months of winter you can expect an average low temperature of -30°F.

Keep in mind that USDA zone info for Cambridge is just an average and the actual date of last frost is different every year. Half of the time in Cambridge it frosts late in the year after May 15 so just be sure to be ready to protect your campanula if you have one of those late frosts.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Cambridge

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