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.

It's possible to estimate when it's possible to plant periwinkles by referring to the USDA zone info for Morton.

Planting Calendar for Periwinkles

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

Since periwinkles require warm weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Morton 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 couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is April 15 in Morton. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Morton may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Morton last frost occurs after April 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Morton

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 Morton

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