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

You can figure out when it's the best time to plant periwinkles in Cape Girardeau by looking at the USDA zone info.

Planting Calendar for Periwinkles

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

Periwinkles require warm weather which means that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant periwinkles in Cape Girardeau 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. Starting your periwinkles indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Cape Girardeau. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Cape Girardeau is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Cape Girardeau last frost occurs after April 15 be ready to protect your periwinkles if you have one of those late frosts.

USDA Zone Info for Cape Girardeau

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 Cape Girardeau

You may be interested in your other planting guides for Cape Girardeau.