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.

The USDA zone info for Port Washington can be reviewed to figure out when it's possible to plant periwinkles.

Planting Calendar for Periwinkles

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

You can not plant periwinkles until after the last frost has passed because they require warm weather.

The earliest that you can plant periwinkles in Port Washington 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 grow to maturity. 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 Port Washington. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Port Washington is an average the actual date of last frost will vary from year to year. Since half of the time in Port Washington you get a frost after April 15 be ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Port Washington

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 Port Washington

You may be interested in your other planting guides for Port Washington.