One of the best tools that you have as gardeners to help us estimate 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.

A way of getting a good idea when you can plant periwinkles is to check out the USDA zone info for Scottsbluff.

Planting Calendar for Periwinkles

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

Periwinkles do not do well in cold weather which means that you must 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 Scottsbluff 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 grow to maturity. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

In Scottsbluff the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Scottsbluff is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Scottsbluff it frosts late in the year after April 15 be ready to protect your periwinkles if you have one of those late frosts.

USDA Zone Info for Scottsbluff

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Scottsbluff

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