The USDA Zone info is a great tool for gardeners to help us determine 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.

A common way of determining when it's possible to plant four-o-clock flower is to look at the USDA zone info for South Houston.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost.

Since four-o-clock flower do not do well in cold weather you need 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 South Houston 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. Any later than that and your four-o-clock flower may not have a chance to fully mature. You can get started a few weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

In South Houston the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for South Houston is not always accurate and the actual date of last frost is different every year. Since half of the time in South Houston it frosts late in the year after February 15 be ready to cover your four-o-clock flower if you have a late frost.

USDA Zone Info for South Houston

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in South Houston

You may be interested in your other planting guides for South Houston.