One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Dallas you can figure out when it's a good idea to plant catharanthus by using the USDA zone info.

Planting Calendar for Catharanthus

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

Catharanthus do not do well in cold weather which means that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in Dallas 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. If you wait any later than that and your catharanthus may not have a chance to fully mature. If you are starting your catharanthus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Dallas the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Dallas may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Dallas you get a frost after April 15 be ready to cover your catharanthus in the event of one of those late frosts.

USDA Zone Info for Dallas

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 Dallas

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