One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Opp can be reviewed to determine when it's the best time to plant periwinkles.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's a bad idea to plant periwinkles until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant periwinkles in Opp 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 little bit earlier by starting your periwinkles indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Opp. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Opp is just an average the actual date of last frost will vary from year to year. Since half of the time in Opp you get a frost after March 15 be ready to protect your periwinkles in the event of a surprise late frost.

USDA Zone Info for Opp

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Opp

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