One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 Effingham you can figure out when it's a good idea to plant periwinkles 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.

It's probably a bad idea to plant periwinkles until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant periwinkles in Effingham 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 grow to maturity. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is April 15 in Effingham. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Effingham is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Effingham you get a frost after April 15 so make sure that you are ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Effingham

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 Effingham

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