One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Newberg should be reffered to in order to determine 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 all chance of frost has passed.

Periwinkles are not cold tolerant which tells us that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Newberg 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 grow to maturity. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Newberg. In the coldest months of winter you should expect an average low temperature of 15°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Newberg and it changes from year to year. Half of the time in Newberg last frost occurs after March 15 so make sure that you are ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Newberg

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 Newberg

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