Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Colby you can estimate when you can plant browallia by reviewing the USDA zone info.

Planting Calendar for Browallia

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

Browallia require warm weather which tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant browallia in Colby 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. If you wait 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 Colby the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Colby is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Colby there is a last frost after April 15 be ready to protect your browallia if you have a surprise late frost.

USDA Zone Info for Colby

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 Colby

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