One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

In Princeton you can estimate when it's the best time to plant campanula by referring to the USDA zone info.

Planting Calendar for Campanula

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

Campanula do ok in a little bit of cold which tells us that you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant campanula in Princeton 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 campanula and expect a good harvest is probably September. You probably don't want to wait any later than that or else 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

The average date of last frost is April 15 in Princeton. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Princeton is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Princeton you get surprised by a frost after April 15 so make sure that you are ready to protect your campanula in the event of one of those late frosts.

USDA Zone Info for Princeton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Princeton

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