The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when it's possible to plant periwinkles by referring to the USDA zone info for Siler City.

Planting Calendar for Periwinkles

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

Periwinkles require warm weather which tells us that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Siler City 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 periwinkles and expect a good harvest is probably August. You probably don't want to wait any later than that or else your periwinkles may not have a chance to really do well. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Siler City. You can expect an average low temperature of 5°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Siler City and it is different every year. Since half of the time in Siler City you get a frost after April 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Siler City

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 Siler City

You may be interested in your other planting guides for Siler City.