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

In Red Oak you can estimate when it's possible to plant periwinkles by using 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 not a good 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 Red Oak 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 couple of weeks earlier.

Last Frost Date

In Red Oak the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Red Oak may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Red Oak you get a frost after April 15 so just be sure to be ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Red Oak

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Red Oak

You may be interested in your other planting guides for Red Oak.