One of the first steps you take when you are figuring out your gardening schedule is find your 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.

One way of making a decision about when it's a good idea to plant periwinkles is to check out the USDA zone info for Maple Valley.

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 it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Maple Valley 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 really do well. If you are starting your periwinkles indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Maple Valley the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

It's important to remember that USDA zone info for Maple Valley may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Maple Valley you get surprised by a frost after March 15 so make sure that you are ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Maple Valley

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 Maple Valley

You may be interested in your other planting guides for Maple Valley.