Before planting it is a good idea to find your USDA Zone info to figure out 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.

A common way of figuring out when it's the best time to plant periwinkles is to refer to the USDA zone info for Kosciusko.

Planting Calendar for Periwinkles

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

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

The earliest that you can plant periwinkles in Kosciusko 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 little bit earlier.

Last Frost Date

In Kosciusko the average date of last frost happens on March 15. You can expect an average low temperature of 10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Kosciusko may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Kosciusko there is a last frost after March 15 so just be sure to be ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Kosciusko

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Kosciusko

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