The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant periwinkles in Johnson City can be determined 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 has passed.

Since periwinkles are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Johnson City 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 fully mature. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Johnson City. It might get as low as -15°F during the coldest months of winter.

Keep in mind that USDA zone info for Johnson City is an average and the actual date of last frost is different every year. Since half of the time in Johnson City you get a frost after April 15 be ready to cover your periwinkles if you have a surprise late frost.

USDA Zone Info for Johnson City

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 Johnson City

You may be interested in your other planting guides for Johnson City.