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

By using the USDA zone info for Wyoming it's possible to figure out when you can plant catharanthus.

Planting Calendar for Catharanthus

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

You really shouldn't plant catharanthus until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant catharanthus in Wyoming 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 catharanthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your catharanthus may not have a chance to fully mature. Starting your catharanthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Wyoming. It might get as low as -15°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 Wyoming and it is different every year. Since half of the time in Wyoming it frosts late in the year after April 15 be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Wyoming

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 Wyoming

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