One of the first steps you take when you are getting a good idea 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.

It's possible to figure out when it's the best time to plant catharanthus by looking at the USDA zone info for Flossmoor.

Planting Calendar for Catharanthus

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

Since catharanthus are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Flossmoor 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

The average date of last frost is April 15 in Flossmoor. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Flossmoor may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Flossmoor last frost occurs after April 15 be ready to protect your catharanthus in the event of a late frost.

USDA Zone Info for Flossmoor

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 Flossmoor

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