The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when it's the best time to plant lisianthus is to examine the USDA zone info for Colby.

Planting Calendar for Lisianthus

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

Since lisianthus do not do well in cold weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant lisianthus 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 lisianthus and expect a good harvest is probably August. If you wait any later than that and your lisianthus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your lisianthus indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Colby. In the coldest months of winter you should expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Colby is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Colby you get a frost after April 15 be ready to protect your lisianthus if you have one of those late frosts.

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.