Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of estimating when to plant periwinkles is to consult the USDA zone info for Conshohocken.

Planting Calendar for Periwinkles

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

Periwinkles require warm weather which tells us that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Conshohocken 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. Starting your periwinkles indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Conshohocken. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Conshohocken may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Conshohocken you get a frost after April 15 so just be sure to be ready to cover your periwinkles in the event of a late frost.

USDA Zone Info for Conshohocken

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Conshohocken

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