The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's a good idea to plant four-o-clock flower by checking out the USDA zone info for Fairfax.

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 are not cold tolerant it's important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower in Fairfax 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. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to fully mature. Starting your four-o-clock flower 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 Fairfax. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Fairfax is not always accurate the actual date of last frost will vary from year to year. Half of the time in Fairfax last frost occurs after February 15 so make sure that you are ready to cover your four-o-clock flower if you have a late frost.

USDA Zone Info for Fairfax

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 Fairfax

You may be interested in your other planting guides for Fairfax.