One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

It's a good idea to estimate when it's the best time to plant periwinkles by using the USDA zone info for Herkimer.

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 has passed because they do not do well in cold weather.

The earliest that you can plant periwinkles in Herkimer 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. Any later than that and your periwinkles may not have a chance to grow to maturity. If you are starting your periwinkles indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Herkimer. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Herkimer may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Herkimer you get surprised by a frost after April 15 be ready to protect your periwinkles in the event of one of those late frosts.

USDA Zone Info for Herkimer

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 Herkimer

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