One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Atascadero it's possible to figure out when to plant periwinkles.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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 Atascadero 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 really do well. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is February 15 in Atascadero. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for Atascadero is not always accurate the actual date of last frost is different every year. Since half of the time in Atascadero there is a last frost after February 15 be ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Atascadero

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 Atascadero

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