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

It's a good idea to determine when to plant periwinkles by looking at the USDA zone info for Gillette.

Planting Calendar for Periwinkles

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

Since periwinkles are not cold tolerant it is important to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Gillette is May. However, you really should wait until June 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 really do well. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average the last frost is on May 15 in Gillette. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Gillette and it is different every year. Since half of the time in Gillette it frosts late in the year after May 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Gillette

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Gillette

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