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

In Boulder you can figure out when you can plant brunfelsia by looking at the USDA zone info.

Planting Calendar for Brunfelsia

Frost tolerance for brunfelsia:	Not tolerant of frost.
When to plant:	After the last frost.

Since brunfelsia require warm weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant brunfelsia in Boulder is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant brunfelsia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your brunfelsia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your brunfelsia indoors.

Last Frost Date

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

Remember that USDA zone info for Boulder is an average and the actual date of last frost changes from year to year. Half of the time in Boulder it frosts late in the year after April 15 so be sure to be ready to protect your brunfelsia in the event of a late frost.

USDA Zone Info for Boulder

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 Boulder

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