One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Harper Woods you can estimate when it's a good idea to plant periwinkles by checking out the USDA zone info.

Planting Calendar for Periwinkles

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

You really shouldn't plant periwinkles until after the last frost because they require warm weather.

The earliest that you can plant periwinkles in Harper Woods 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 really do well. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is April 15 in Harper Woods. 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 Harper Woods is just an average and the actual date of last frost changes from year to year. Since half of the time in Harper Woods you get a frost after April 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Harper Woods

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 Harper Woods

You may be interested in your other planting guides for Harper Woods.