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.

By using the USDA zone info for Portage you will be able to figure out when it's possible to plant osteospermum.

Planting Calendar for Osteospermum

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

Osteospermum do ok in mild cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant osteospermum in Portage 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. Any later than that and your osteospermum may not have a chance to fully mature. Starting your osteospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Portage is just an average the actual date of last frost will vary from year to year. Half of the time in Portage last frost occurs after April 15 so always be ready to protect your osteospermum if you have a late frost.

USDA Zone Info for Portage

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 Portage

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