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.

A common way of figuring out when to plant periwinkles is to check out the USDA zone info for Prineville.

Planting Calendar for Periwinkles

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

It's 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 Prineville 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. If you wait 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 the last frost when the weather gets warmer is on April 15 in Prineville. In the coldest months of winter you should expect an average low temperature of -5°F.

Keep in mind that USDA zone info for Prineville is just an average and the actual date of last frost will vary from year to year. Half of the time in Prineville it frosts late in the year after April 15 so just be sure to be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Prineville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Prineville

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