One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant periwinkles is to consult the USDA zone info for Germantown.

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 tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant periwinkles in Germantown 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 really do well. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

In Germantown the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Germantown and it is different every year. Half of the time in Germantown you get a frost after April 15 so be sure to be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Germantown

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 Germantown

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