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.

You will be able to estimate when it's the best time to plant catharanthus by checking out the USDA zone info for Piedmont.

Planting Calendar for Catharanthus

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

Since catharanthus require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in Piedmont 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 couple of weeks earlier by starting your catharanthus indoors.

Last Frost Date

In Piedmont the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Piedmont is just an average the actual date of last frost changes from year to year. Half of the time in Piedmont it frosts late in the year after April 15 so just be sure to be ready to cover your catharanthus in the event of a surprise late frost.

USDA Zone Info for Piedmont

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 Piedmont

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