One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 reviewing the USDA zone info for Frankfort.

Planting Calendar for Periwinkles

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

It's a bad idea to plant periwinkles until after the last frost because they are not cold tolerant.

The earliest that you can plant periwinkles in Frankfort 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. Any later than that and 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 couple of weeks earlier.

Last Frost Date

In Frankfort the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Frankfort may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Frankfort you get a frost after April 15 so just be sure to be ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Frankfort

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 Frankfort

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