Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Tomball can be reviewed to estimate when it's the best time to plant flower-of-an-hour.

Planting Calendar for Flower-of-an-Hour

Frost tolerance for flower-of-an-hour:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Flower-of-an-Hour are barely cold tolerant which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant flower-of-an-hour in Tomball 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 flower-of-an-hour and expect a good harvest is probably September. Any later than that and your flower-of-an-hour may not have a chance to really do well. You can get started a couple of weeks earlier by starting your flower-of-an-hour indoors.

Last Frost Date

In Tomball the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Tomball and it can change quite a bit from year to year. Since half of the time in Tomball there is a last frost after February 15 be ready to protect your flower-of-an-hour if you have a late frost.

USDA Zone Info for Tomball

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 Tomball

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