One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 Rupert can be used to determine when to plant periwinkles.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Rupert 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. Starting your periwinkles indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Rupert may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Rupert you get surprised by a frost after April 15 so make sure that you are ready to protect your periwinkles in the event of one of those late frosts.

USDA Zone Info for Rupert

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Rupert

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