One of the first steps you take when you are estimating 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.

By looking at the USDA zone info for Winnetka it's a good idea to determine when it's a good idea to plant catharanthus.

Planting Calendar for Catharanthus

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

It's probably a bad idea to plant catharanthus until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant catharanthus in Winnetka 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. If you wait any later than that and your catharanthus may not have a chance to really do well. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost is on April 15 in Winnetka. 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 not always accurate because it is based on the USDA zone info for Winnetka and it changes from year to year. Half of the time in Winnetka last frost occurs after April 15 so be sure to be ready to protect your catharanthus in the event of a surprise late frost.

USDA Zone Info for Winnetka

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 Winnetka

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