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

You will be able to figure out when it's possible to plant periwinkles by using the USDA zone info for Port Lavaca.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since periwinkles are not cold tolerant you must wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Port Lavaca 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 periwinkles and expect a good harvest is probably September. Any later than that and your periwinkles may not have a chance to grow to maturity. Starting your periwinkles indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Port Lavaca the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Port Lavaca and it will vary from year to year. Half of the time in Port Lavaca you get surprised by a frost after February 15 so make sure that you are ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Port Lavaca

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Port Lavaca

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