One of the best tools that you have as gardeners to help us determine 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 best time to plant bidens in Suisun City 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 the last frost.

Bidens require warm weather which tells us that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant bidens in Suisun City 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. Any later than that and your bidens may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your bidens indoors.

Last Frost Date

The average date of last frost is February 15 in Suisun City. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Suisun City is an average the actual date of last frost will vary from year to year. Half of the time in Suisun City you get a frost after February 15 so just be sure to be ready to cover your bidens in the event of a surprise late frost.

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.