Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's the best time to plant purple coneflower in San Ramon by referring to the USDA zone info.

Planting Calendar for Purple Coneflower

Frost tolerance for purple coneflower:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since purple coneflower do ok in moderate cold you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

The average date of last frost is February 15 in San Ramon. In the coldest months of winter you can expect an average low temperature of 25°F.

Remember that USDA zone info for San Ramon may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in San Ramon there is a last frost after February 15 be ready to protect your purple coneflower 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.