One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Port Arthur you can figure out when it's the best time to plant catharanthus by looking at the USDA zone info.

Planting Calendar for Catharanthus

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

Catharanthus require warm 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 Port Arthur is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your catharanthus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your catharanthus indoors.

Last Frost Date

In Port Arthur the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Port Arthur is not always accurate and the actual date of last frost is different every year. Half of the time in Port Arthur last frost occurs after February 15 so make sure that you are prepared to cover your catharanthus in the event of a late frost.

USDA Zone Info for Port Arthur

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Port Arthur

You may be interested in your other planting guides for Port Arthur.