Before planting it is a good idea to find your USDA Zone info to estimate 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.

In Radcliff you can figure out when you can plant periwinkles by referring to the USDA zone info.

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 need to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Radcliff 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. Starting your periwinkles indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Radcliff. In the coldest months of winter you can expect an average low temperature of -5°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Radcliff and it will vary from year to year. Half of the time in Radcliff last frost occurs after April 15 so make sure that you are ready to cover your periwinkles if you have a surprise late frost.

USDA Zone Info for Radcliff

Here is the info for USDA Zone 6b.

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

Plants to Grow in Radcliff

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