Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Clayton you should be able to estimate when it's a good idea to plant periwinkles.

Planting Calendar for Periwinkles

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

It's probably a bad idea to plant periwinkles until after the last frost has passed because they require warm weather.

The earliest that you can plant periwinkles in Clayton 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 fully mature. 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

The average date of last frost is April 15 in Clayton. In the coldest months of winter you should expect an average low temperature of 0°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Clayton and it can change quite a bit from year to year. Half of the time in Clayton it frosts late in the year after April 15 so make sure that you are ready to protect your periwinkles in the event of a surprise late frost.

USDA Zone Info for Clayton

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Clayton

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