Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant sunflowers in San Ramon should be determined by checking out the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's not a good idea to plant sunflowers until after the last frost because they do not do well in cold weather.

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

The last month that you can plant sunflowers and expect a good harvest is probably September. Any later than that and your sunflowers may not have a chance to fully mature. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

In San Ramon the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for San Ramon and it changes from year to year. Since half of the time in San Ramon it frosts late in the year after February 15 be ready to protect your sunflowers if you have 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.