Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 determine when it's the best time to plant periwinkles by using the USDA zone info for Palmetto.

Planting Calendar for Periwinkles

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

Since periwinkles require warm weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Palmetto 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 really do well. If you are starting your periwinkles indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Palmetto. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Palmetto is just an average and the actual date of last frost is different every year. Since half of the time in Palmetto it frosts late in the year after February 15 be ready to cover your periwinkles if you have a surprise late frost.

USDA Zone Info for Palmetto

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 Palmetto

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