When to Plant Periwinkles in Sussex, WI

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant periwinkles by using the USDA zone info for Sussex.


Planting Calendar for Periwinkles

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

It's not a good idea to plant periwinkles until after the last frost when the weather gets warmer because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant periwinkles
Possibly ok, but a risky time to plant periwinkles
Probably not a good time to plant periwinkles

The earliest that you can plant periwinkles in Sussex 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 few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Sussex. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Sussex and it will vary from year to year. Half of the time in Sussex you get surprised by a frost after April 15 so be sure to be ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Sussex

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Sussex

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