One of the best tools that you have as gardeners to help us figure out 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.

The first opportunity to plant bidens in San Ramon should be estimated by using the USDA zone info.

Planting Calendar for Bidens

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

Since bidens require warm weather it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bidens may not have a chance to grow to maturity. Starting your bidens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for San Ramon is not always accurate the actual date of last frost changes from year to year. Since half of the time in San Ramon you get a frost after February 15 be ready to protect your bidens if you have a surprise late frost.

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.