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

The first chance to plant periwinkles in Harrison should be estimated by reviewing the USDA zone info.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You really shouldn't 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 Harrison 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 really do well. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

On average the last frost is on April 15 in Harrison. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Harrison is an average and the actual date of last frost changes from year to year. Since half of the time in Harrison there is a last frost after April 15 be ready to protect your periwinkles in the event of one of those late frosts.

USDA Zone Info for Harrison

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 Harrison

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