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.

A way of estimating when it's a good idea to plant periwinkles is to look at the USDA zone info for Westlake.

Planting Calendar for Periwinkles

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

Periwinkles are not cold tolerant which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant periwinkles in Westlake 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 grow to maturity. Starting your periwinkles indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Westlake. You should expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Westlake may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Westlake there is a last frost after February 15 so just be sure to be ready to protect your periwinkles in the event of a late frost.

USDA Zone Info for Westlake

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 Westlake

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