Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant periwinkles in Ironwood can be figured out by checking out the USDA zone info.

Planting Calendar for Periwinkles

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

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

The earliest that you can plant periwinkles in Ironwood is May. However, you really should wait until June 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 fully mature. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is May 15 in Ironwood. In the coldest months of winter you can expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Ironwood is an average and the actual date of last frost will vary from year to year. Since half of the time in Ironwood you get surprised by a frost after May 15 be ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Ironwood

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Ironwood

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