Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Salt Lake City you can figure out when it's possible to plant periwinkles by using 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.

Since periwinkles are not cold tolerant you must wait until after the last frost before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on April 15 in Salt Lake City. In the coldest months of winter you should expect an average low temperature of 5°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Salt Lake City and it will vary from year to year. Since half of the time in Salt Lake City you get surprised by a frost after April 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Salt Lake City

Here is the info for USDA Zone 7b.

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

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Salt Lake City

You may be interested in your other planting guides for Salt Lake City.