The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant periwinkles in Norman 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.

Periwinkles are not cold tolerant which means that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant periwinkles in Norman 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 really do well. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Norman. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Norman may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Norman last frost occurs after April 15 be ready to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for Norman

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Norman

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