One of the first steps you take when you are estimating your gardening schedule is find your 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 Longmont should be used to determine when it's the best time to plant browallia.

Planting Calendar for Browallia

Frost tolerance for browallia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since browallia require warm weather you really should wait until after all chance of frost has passed before you can plant them.

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

Last Frost Date

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

Since the USDA zone info for Longmont is not always accurate the actual date of last frost changes from year to year. Since half of the time in Longmont you get a frost after April 15 be ready to cover your browallia if you have a late frost.

USDA Zone Info for Longmont

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 Longmont

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