One of the first steps you take when you are figuring out your gardening schedule is find your 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.

In Lake Geneva you can figure out when it's possible to plant catharanthus by referring to the USDA zone info.

Planting Calendar for Catharanthus

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

You can not plant catharanthus until after all chance of frost has passed because they require warm weather.

The earliest that you can plant catharanthus in Lake Geneva 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. Any later than that and your catharanthus may not have a chance to fully mature. You can get started a little bit earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost is on April 15 in Lake Geneva. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for Lake Geneva is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Lake Geneva you get a frost after April 15 so make sure that you are ready to protect your catharanthus if you have one of those late frosts.

USDA Zone Info for Lake Geneva

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 Lake Geneva

You may be interested in your other planting guides for Lake Geneva.