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

In Kerman you can determine when it's the best time 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 require warm weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Kerman 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. Any later than that and your periwinkles may not have a chance to fully mature. If you are starting your periwinkles indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Kerman the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

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

USDA Zone Info for Kerman

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 Kerman

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