The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of estimating when it's a good idea to plant catharanthus is to refer to the USDA zone info for Durham.

Planting Calendar for Catharanthus

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

Since catharanthus require warm weather you really should wait until after the last frost has passed before you can plant them.

The earliest that you can plant catharanthus in Durham 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 really do well. You can get started a couple of weeks earlier by starting your catharanthus indoors.

Last Frost Date

The average date of last frost is April 15 in Durham. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Durham may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Durham you get a frost after April 15 so make sure that you are prepared to cover your catharanthus if you have a late frost.

USDA Zone Info for Durham

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 Durham

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