One of the first steps you take when you are figuring out 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.

You can figure out when it's possible to plant periwinkles in North Royalton by reviewing 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 a bad idea to plant periwinkles until after the last frost because they do not do well in cold weather.

The earliest that you can plant periwinkles in North Royalton 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. Starting your periwinkles indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in North Royalton. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for North Royalton is just an average the actual date of last frost will vary from year to year. Half of the time in North Royalton there is a last frost after April 15 so be sure to be ready to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for North Royalton

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in North Royalton

You may be interested in your other planting guides for North Royalton.