One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for La Crosse can be looked at to figure out when to plant catharanthus.

Planting Calendar for Catharanthus

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

Since catharanthus do not do well in cold weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant catharanthus in La Crosse 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 little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in La Crosse. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for La Crosse is just an average and the actual date of last frost will vary from year to year. Since half of the time in La Crosse you get surprised by a frost after May 15 be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for La Crosse

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 La Crosse

You may be interested in your other planting guides for La Crosse.