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.

One way of figuring out when it's the best time to plant osteospermum is to refer to the USDA zone info for Milwaukee.

Planting Calendar for Osteospermum

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

You can plant osteospermum a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant osteospermum in Milwaukee 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. 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 Milwaukee. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Milwaukee is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Milwaukee last frost occurs after April 15 be ready to protect your osteospermum in the event of a late frost.

USDA Zone Info for Milwaukee

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 Milwaukee

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