Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant catharanthus in Zone 7b can be determined by looking at the USDA zone info.

Planting Calendar for Catharanthus

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

It's a bad idea to plant catharanthus until after the last frost because they are not cold tolerant.

The earliest that you can plant catharanthus in Zone 7b 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 little bit earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Zone 7b. It might get as low as 5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 7b and it will vary from year to year. Since half of the time in Zone 7b there is a last frost after April 15 be ready to cover your catharanthus in the event of a surprise late frost.

USDA Zone Info for Zone 7b

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Zone 7b

You may be interested in your other planting guides for Zone 7b.