One of the first steps you take when you are getting a good idea 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.

The USDA zone info for Johnstown should be used to estimate when to plant periwinkles.

Planting Calendar for Periwinkles

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

It's probably a bad idea to plant periwinkles until after the last frost has passed because they require warm weather.

The earliest that you can plant periwinkles in Johnstown 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. If you are starting your periwinkles indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Johnstown. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that USDA zone info for Johnstown is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Johnstown you get a frost after April 15 be ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Johnstown

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 Johnstown

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