Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Tumwater can be looked at to estimate when it's the best time to plant periwinkles.

Planting Calendar for Periwinkles

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

Periwinkles are not cold tolerant which means that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Tumwater 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 couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is March 15 in Tumwater. It might get as low as 10°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Tumwater and it will vary from year to year. Half of the time in Tumwater you get surprised by a frost after March 15 so just be sure to be ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Tumwater

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Tumwater

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