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.

By referring to the USDA zone info for Mount Vernon it's a good idea to determine when you can plant periwinkles.

Planting Calendar for Periwinkles

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

Since periwinkles require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Mount Vernon 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. 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 March 15 in Mount Vernon. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Mount Vernon may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Mount Vernon last frost occurs after March 15 be ready to protect your periwinkles if you have one of those late frosts.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.