One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Eureka should be read to determine when it's possible 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.

It's probably a bad idea to plant periwinkles until after the last frost because they do not do well in cold weather.

The earliest that you can plant periwinkles in Eureka 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 really do well. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Eureka. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Eureka is just an average and the actual date of last frost changes from year to year. Half of the time in Eureka you get surprised by a frost after February 15 so be sure to be ready to protect your periwinkles if you have one of those late frosts.

USDA Zone Info for Eureka

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Eureka

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