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.

You should be able to estimate when it's possible to plant periwinkles by using the USDA zone info for Seabrook.

Planting Calendar for Periwinkles

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

It's not a good idea to 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 Seabrook is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant periwinkles and expect a good harvest is probably September. Any later than that and your periwinkles may not have a chance to really do well. You can get started a couple of weeks earlier by starting your periwinkles indoors.

Last Frost Date

In Seabrook the average date of last frost happens on February 15. You should expect an average low temperature of 20°F in the coldest months of winter.

Keep in mind that USDA zone info for Seabrook is just an average and the actual date of last frost is different every year. Half of the time in Seabrook there is a last frost after February 15 so just be sure to be ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Seabrook

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Seabrook

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