One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The earliest that you can plant calliopsis in Winthrop Harbor can be figured out by looking at the USDA zone info.

Planting Calendar for Calliopsis

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

Since calliopsis are not cold tolerant you really should wait until after the last frost has passed before you can plant them.

The earliest that you can plant calliopsis in Winthrop Harbor 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 calliopsis and expect a good harvest is probably August. If you wait any later than that and your calliopsis may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your calliopsis indoors.

Last Frost Date

The average date of last frost is April 15 in Winthrop Harbor. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Winthrop Harbor is not always accurate the actual date of last frost changes from year to year. Half of the time in Winthrop Harbor it frosts late in the year after April 15 so always be ready to protect your calliopsis in the event of one of those late frosts.

USDA Zone Info for Winthrop Harbor

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 Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.