Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 look at the USDA zone info for Owatonna.

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 bit earlier in the year because they are moderately cold tolerant.

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

The last month that you can plant osteospermum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your osteospermum may not have a chance to really do well. Starting your osteospermum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Owatonna. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Owatonna may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Owatonna you get a frost after May 15 so be sure to be ready to protect your osteospermum in the event of a late frost.

USDA Zone Info for Owatonna

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Owatonna

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