The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when you can plant campanula is to use the USDA zone info for Berthoud.

Planting Calendar for Campanula

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

Campanula are moderately cold tolerant which tells us that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant campanula in Berthoud 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. If you wait any later than that and your campanula may not have a chance to grow to maturity. You can get started a little bit earlier by starting your campanula indoors.

Last Frost Date

On average the last frost is on April 15 in Berthoud. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Berthoud and it will vary from year to year. Half of the time in Berthoud there is a last frost after April 15 so make sure that you are prepared to protect your campanula if you have a late frost.

USDA Zone Info for Berthoud

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Berthoud

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