One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Williams you should be able to determine when it's a good idea 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.

You can plant osteospermum just a bit earlier in the year because they do well in moderate cold.

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

The last month that you can plant osteospermum and expect a good harvest is probably October. If you wait any later than that and your osteospermum may not have a chance to fully mature. If you are starting your osteospermum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Williams the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Williams is not always accurate the actual date of last frost is different every year. Since half of the time in Williams last frost occurs after February 15 be ready to cover your osteospermum if you have a late frost.

USDA Zone Info for Williams

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Williams

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