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.

A way of determining when it's a good idea to plant campanula is to look at the USDA zone info for Lewiston.

Planting Calendar for Campanula

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

Since campanula are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant campanula in Lewiston 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. Any later than that and your campanula may not have a chance to fully mature. You can get started a little bit earlier by starting your campanula indoors.

Last Frost Date

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

Since the USDA zone info for Lewiston is not always accurate the actual date of last frost is different every year. Since half of the time in Lewiston you get surprised by a frost after April 15 be ready to protect your campanula in the event of a surprise late frost.

USDA Zone Info for Lewiston

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 Lewiston

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