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

In Mukilteo you can determine when it's a good idea to plant periwinkles by looking at 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 you need to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Mukilteo is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant periwinkles and expect a good harvest is probably August. Any later than that and your periwinkles may not have a chance to fully mature. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Mukilteo. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Mukilteo is just an average the actual date of last frost changes from year to year. Since half of the time in Mukilteo you get a frost after March 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Mukilteo

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Mukilteo

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