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

A way of determining when to plant browallia is to examine the USDA zone info for Vail.

Planting Calendar for Browallia

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

It's probably a bad idea to plant browallia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant browallia in Vail is May. However, you really should wait until June 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. Any later than that and your browallia may not have a chance to fully mature. If you are starting your browallia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Vail the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Vail is just an average the actual date of last frost changes from year to year. Half of the time in Vail last frost occurs after May 15 so be sure to be ready to protect your browallia in the event of a surprise late frost.

USDA Zone Info for Vail

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 Vail

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