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

You can figure out when it's a good idea to plant periwinkles in Huntley by reviewing the USDA zone info.

Planting Calendar for Periwinkles

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

It's probably a bad idea to plant periwinkles until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant periwinkles in Huntley 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. If you are starting your periwinkles indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Huntley the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Huntley is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Huntley last frost occurs after April 15 so make sure that you are prepared to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Huntley

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Huntley

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