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

You should be able to determine when it's a good idea to plant catharanthus by using the USDA zone info for Grayslake.

Planting Calendar for Catharanthus

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

Since catharanthus do not do well in cold weather it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in Grayslake 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 grow to maturity. Starting your catharanthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Grayslake. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Grayslake may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Grayslake you get a frost after April 15 be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Grayslake

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 Grayslake

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