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 USDA zone info for Suisun City should be reviewed to determine when it's the best time to plant purple coneflower.

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.

Purple Coneflower do ok in mild cold which tells us that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant purple coneflower in Suisun City 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. Any later than that and 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

On average all chance of frost has passed is on February 15 in Suisun City. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Suisun City is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Suisun City there is a last frost after February 15 be ready to protect your purple coneflower if you have one of those late frosts.

USDA Zone Info for Suisun City

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 Suisun City

You may be interested in your other planting guides for Suisun City.