One of the first steps you take when you are making a decision about 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.

You will be able to determine when it's a good idea to plant osteospermum by using the USDA zone info for Stillwater.

Planting Calendar for Osteospermum

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

Since osteospermum do well in moderate cold you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant osteospermum in Stillwater 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. Any later than that and your osteospermum may not have a chance to really do well. 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 May 15 in Stillwater. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Stillwater is just an average the actual date of last frost is different every year. Since half of the time in Stillwater there is a last frost after May 15 be ready to cover your osteospermum if you have one of those late frosts.

USDA Zone Info for Stillwater

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 Stillwater

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