One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

The first chance to plant periwinkles in Mountlake Terrace can be determined by using 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 are not cold tolerant 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 Mountlake Terrace 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. You probably don't want to wait any later than that or else your periwinkles may not have a chance to fully mature. If you are starting your periwinkles indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Mountlake Terrace the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that USDA zone info for Mountlake Terrace is just an average and the actual date of last frost will vary from year to year. Since half of the time in Mountlake Terrace there is a last frost after March 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Mountlake Terrace

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 Mountlake Terrace

You may be interested in your other planting guides for Mountlake Terrace.