Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when you can plant catharanthus is to refer to the USDA zone info for Willmar.

Planting Calendar for Catharanthus

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

You should not plant catharanthus until after the last frost because they require warm weather.

The earliest that you can plant catharanthus in Willmar 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 catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to really do well. Starting your catharanthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Willmar the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Willmar is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Willmar there is a last frost after May 15 so make sure that you are ready to protect your catharanthus if you have one of those late frosts.

USDA Zone Info for Willmar

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 Willmar

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