One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to determine when it's a good idea to plant periwinkles by checking out the USDA zone info for Raleigh.

Planting Calendar for Periwinkles

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

Periwinkles are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Raleigh 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. If you wait 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Raleigh. In the coldest months of winter you should expect an average low temperature of 5°F.

Keep in mind 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 Raleigh and it changes from year to year. Half of the time in Raleigh it frosts late in the year after April 15 so always be ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Raleigh

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 Raleigh

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