One of the first steps you take when you are getting a good idea 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.

One way of making a decision about when it's the best time to plant zinnia is to check out the USDA zone info for San Pablo.

Planting Calendar for Zinnia

Frost tolerance for zinnia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You really shouldn't plant zinnia until after the last frost because they do not do well in cold weather.

The earliest that you can plant zinnia in San Pablo is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant zinnia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your zinnia may not have a chance to fully mature. If you are starting your zinnia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in San Pablo. You can expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Pablo is an average the actual date of last frost is different every year. Since half of the time in San Pablo there is a last frost after January 31 be ready to cover your zinnia if you have a surprise late frost.

USDA Zone Info for San Pablo

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Pablo

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