One of the first steps you take when you are getting a good idea 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.

You should be able to estimate when it's a good idea to plant lisianthus by checking out the USDA zone info for Rapid City.

Planting Calendar for Lisianthus

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

Since lisianthus are not cold tolerant you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant lisianthus in Rapid City 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 grow to maturity. You can get started a couple of weeks earlier by starting your lisianthus indoors.

Last Frost Date

The average date of last frost is April 15 in Rapid City. It might get as low as -20°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Rapid City and it changes from year to year. Half of the time in Rapid City there is a last frost after April 15 so always be ready to cover your lisianthus if you have a surprise late frost.

USDA Zone Info for Rapid City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Rapid City

You may be interested in your other planting guides for Rapid City.