The USDA Zone info is a great tool for gardeners to help us determine your gardening 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 Dewitt it's a good idea to estimate when it's possible 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.

Since periwinkles require warm weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Dewitt 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 really do well. 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 Dewitt. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Dewitt is just an average the actual date of last frost will vary from year to year. Half of the time in Dewitt there is a last frost after April 15 so be sure to be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Dewitt

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Dewitt

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