One of the best tools that you have as gardeners to help us estimate 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 can estimate when to plant osteospermum in Winthrop Harbor by reviewing the USDA zone info.

Planting Calendar for Osteospermum

Frost tolerance for osteospermum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Osteospermum tend to make it in a little bit of cold which means that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant osteospermum in Winthrop Harbor is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant osteospermum and expect a good harvest is probably September. If you wait any later than that and your osteospermum may not have a chance to fully mature. You can get started a little bit earlier by starting your osteospermum indoors.

Last Frost Date

The average date of last frost is April 15 in Winthrop Harbor. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Winthrop Harbor is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Winthrop Harbor it frosts late in the year after April 15 so make sure that you are prepared to cover your osteospermum in the event of a late frost.

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.