Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

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 it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Hamilton 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 grow to maturity. You can get started a few weeks earlier by starting your periwinkles indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Hamilton. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Hamilton is not always accurate the actual date of last frost changes from year to year. Since half of the time in Hamilton you get surprised by a frost after April 15 be ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Hamilton

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 Hamilton

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