The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant periwinkles in Mount Horeb should be estimated by checking out the USDA zone info.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant periwinkles in Mount Horeb 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 really do well. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Mount Horeb. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Mount Horeb is an average the actual date of last frost will vary from year to year. Half of the time in Mount Horeb you get surprised by a frost after April 15 so make sure that you are ready to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for Mount Horeb

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 Mount Horeb

You may be interested in your other planting guides for Mount Horeb.