One of the first steps you take when you are estimating 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.

One way of estimating when it's possible to plant periwinkles is to examine the USDA zone info for Huron.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold weather it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Huron 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 grow to maturity. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Huron. It might get as low as 20°F during the coldest months of winter.

It's important to remember that USDA zone info for Huron is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Huron it frosts late in the year after February 15 be ready to cover your periwinkles in the event of one of those late frosts.

USDA Zone Info for Huron

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 Huron

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