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 a good idea to determine when it's possible to plant catharanthus by checking out the USDA zone info for Richardson.

Planting Calendar for Catharanthus

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

Catharanthus require warm weather which tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant catharanthus in Richardson 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 grow to maturity. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

In Richardson the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Richardson is not always accurate the actual date of last frost changes from year to year. Half of the time in Richardson it frosts late in the year after March 15 so make sure that you are prepared to cover your catharanthus in the event of one of those late frosts.

USDA Zone Info for Richardson

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Richardson

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