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.

In Jackson you can estimate when to plant periwinkles by using 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.

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

The earliest that you can plant periwinkles in Jackson is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant periwinkles and expect a good harvest is probably September. If you wait any later than that and your periwinkles may not have a chance to fully mature. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Jackson. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Jackson is not always accurate the actual date of last frost changes from year to year. Half of the time in Jackson there is a last frost after February 15 so make sure that you are prepared to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for Jackson

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Jackson

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