One of the first steps you take when you are figuring out your gardening schedule is find your 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.

The best time to plant angelonia in Boulder should be estimated by checking out the USDA zone info.

Planting Calendar for Angelonia

Frost tolerance for angelonia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Angelonia are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant angelonia in Boulder 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 angelonia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your angelonia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your angelonia indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Boulder is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Boulder it frosts late in the year after April 15 be ready to cover your angelonia if you have 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.