One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Havre De Grace it's a good idea to estimate when it's a good idea to plant periwinkles.

Planting Calendar for Periwinkles

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

You really shouldn't plant periwinkles until after the last frost because they do not do well in cold weather.

The earliest that you can plant periwinkles in Havre De Grace 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 fully mature. 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

In Havre De Grace the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Havre De Grace and it can change quite a bit from year to year. Since half of the time in Havre De Grace last frost occurs after April 15 be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Havre De Grace

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 Havre De Grace

You may be interested in your other planting guides for Havre De Grace.