The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant osteospermum by looking at the USDA zone info for Grass Valley.

Planting Calendar for Osteospermum

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

Osteospermum tend to make it in a little bit of cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant osteospermum in Grass Valley 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. 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 little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Grass Valley. You can expect an average low temperature of 20°F in the coldest months of winter.

Remember that USDA zone info for Grass Valley is just an average and the actual date of last frost is different every year. Half of the time in Grass Valley there is a last frost after February 15 so just be sure to be ready to protect your osteospermum in the event of a surprise late frost.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

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

Plants to Grow in Grass Valley

You may be interested in your other planting guides for Grass Valley.