One of the first steps you take when you are determining your gardening schedule is find your 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 San Ramon you will be able to determine when you can plant pyrethrum.

Planting Calendar for Pyrethrum

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

Pyrethrum tend to make it in some cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant pyrethrum in San Ramon 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 pyrethrum and expect a good harvest is probably October. You probably don't want to wait any later than that or else your pyrethrum may not have a chance to fully mature. If you are starting your pyrethrum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in San Ramon. You should expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for San Ramon is not always accurate and the actual date of last frost changes from year to year. Half of the time in San Ramon last frost occurs after February 15 so just be sure to be ready to cover your pyrethrum in the event of one of those late frosts.

USDA Zone Info for San Ramon

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 Ramon

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