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 estimating when it's a good idea to plant osteospermum is to examine the USDA zone info for San Jose.

Planting Calendar for Osteospermum

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

Osteospermum do well in moderate cold which tells us that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant osteospermum in San Jose 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 really do well. Starting your osteospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for San Jose is an average the actual date of last frost changes from year to year. Since half of the time in San Jose last frost occurs after February 15 be ready to protect your osteospermum in the event of one of those late frosts.

USDA Zone Info for San Jose

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 San Jose

You may be interested in your other planting guides for San Jose.