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.

You can determine when it's possible to plant four-o-clock flower in Suisun City by looking at the USDA zone info.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since four-o-clock flower require warm weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant four-o-clock flower 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 four-o-clock flower and expect a good harvest is probably September. If you wait any later than that and your four-o-clock flower may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Suisun City and it will vary from year to year. Since half of the time in Suisun City last frost occurs after February 15 be ready to protect your four-o-clock flower in the event of a 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.