Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Marinette you can figure out when to plant periwinkles by using the USDA zone info.

Planting Calendar for Periwinkles

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

Since periwinkles are not cold tolerant you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Marinette 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 really do well. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is April 15 in Marinette. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Marinette is an average the actual date of last frost changes from year to year. Half of the time in Marinette you get surprised by a frost after April 15 so be sure to be ready to cover your periwinkles if you have a surprise late frost.

USDA Zone Info for Marinette

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 Marinette

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