When can I plant Periwinkles in Zone 1b

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

The USDA zone info for Zone 1b should be looked at to figure out when it's a good idea to plant periwinkles.


Planting Calendar for Periwinkles

Frost tolerance for periwinkles: Not tolerant of frost.
When you should plant them: After all chance of frost has passed.

It's a bad idea to plant periwinkles until after the last frost when the weather gets warmer because they are not cold tolerant.

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 Zone 1b is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant periwinkles and expect a good harvest is probably July. 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 few weeks earlier.

Last Frost Date

The average date of last frost is June 15 in Zone 1b. We should expect an average low temperature of -55°F in the coldest months of winter.

Keep in mind that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 1b and it changes from year to year. Half of the time in Zone 1b it frosts late in the year after June 15 so be sure to be ready to cover your periwinkles if we have a surprise late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-55°F
Highest Expected Low-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in our other planting guides for Zone 1b.