One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Austin can be reviewed to determine when it's the best time to plant campanula.

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 some cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant campanula in Austin 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. 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 few weeks earlier by starting your campanula indoors.

Last Frost Date

The average date of last frost is May 15 in Austin. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Austin is an average the actual date of last frost changes from year to year. Half of the time in Austin it frosts late in the year after May 15 so make sure that you are prepared to protect your campanula in the event of one of those late frosts.

USDA Zone Info for Austin

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Austin

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