The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Dayton you can determine when to 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 all chance of frost has passed.

You should not plant periwinkles until after the last frost because they are not cold tolerant.

The earliest that you can plant periwinkles in Dayton is May. However, you really should wait until June 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. 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

On average all chance of frost has passed is on May 15 in Dayton. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Dayton is just an average the actual date of last frost changes from year to year. Since half of the time in Dayton there is a last frost after May 15 be ready to cover your periwinkles in the event of one of those late frosts.

USDA Zone Info for Dayton

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Dayton

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