One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Springfield you can estimate when it's a good idea to plant periwinkles by referring to the USDA zone info.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold 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 Springfield 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 grow to maturity. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

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

Since the USDA zone info for Springfield is an average the actual date of last frost is different every year. Half of the time in Springfield last frost occurs after April 15 so just be sure to be ready to protect your periwinkles in the event of a surprise late frost.

USDA Zone Info for Springfield

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 Springfield

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