The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Harrisonville you can estimate when you can plant periwinkles by reviewing the USDA zone info.

Planting Calendar for Periwinkles

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

Periwinkles do not do well in cold weather which tells us that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Harrisonville 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. You probably don't want to wait any later than that or else your periwinkles may not have a chance to grow to maturity. 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

In Harrisonville the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Harrisonville is just an average the actual date of last frost is different every year. Half of the time in Harrisonville there is a last frost after April 15 so make sure that you are ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Harrisonville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Harrisonville

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