One of the first steps you take when you are estimating 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.

A common way of making a decision about when to plant catharanthus is to examine the USDA zone info for Altus.

Planting Calendar for Catharanthus

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

It's probably not a good idea to plant catharanthus until after the last frost because they do not do well in cold weather.

The earliest that you can plant catharanthus in Altus 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 little bit earlier.

Last Frost Date

In Altus the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 5°F.

Since the USDA zone info for Altus is an average the actual date of last frost changes from year to year. Half of the time in Altus you get surprised by a frost after April 15 so be sure to be ready to protect your catharanthus if you have one of those late frosts.

USDA Zone Info for Altus

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 Altus

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