One of the first steps you take when you are figuring out your gardening schedule is find your 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 estimating when it's possible to plant periwinkles is to check out the USDA zone info for Hampshire.

Planting Calendar for Periwinkles

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

You really shouldn't plant periwinkles until after the last frost because they do not do well in cold weather.

The earliest that you can plant periwinkles in Hampshire 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 fully mature. 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 Hampshire. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Hampshire is an average the actual date of last frost is different every year. Half of the time in Hampshire last frost occurs after April 15 so make sure that you are ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Hampshire

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Hampshire

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