When to Plant Periwinkles in Cornelius, OR

One of the first steps you take when you are estimating 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.

The best time to plant periwinkles in Cornelius can be determined by reviewing the USDA zone info.


Planting Calendar for Periwinkles

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

You should not plant periwinkles until after the last frost has passed because they require warm weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant periwinkles
Possibly ok, but a risky time to plant periwinkles
Probably not a good time to plant periwinkles

The earliest that you can plant periwinkles in Cornelius 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 little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Cornelius. It might get as low as 15°F during the coldest months of winter.

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

USDA Zone Info for Cornelius

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 Low15°F
Highest Expected Low20°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 Cornelius

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