One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when it's the best time to plant periwinkles is to look at the USDA zone info for Placerville.

Planting Calendar for Periwinkles

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

It's probably a bad idea to plant periwinkles until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant periwinkles in Placerville 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. You probably don't want to wait any later than that or else your periwinkles may not have a chance to really do well. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

In Placerville the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Placerville and it is different every year. Half of the time in Placerville there is a last frost after February 15 so be sure to be ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Placerville

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 Placerville

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