One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. 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 Tucson should be reffered to in order to estimate when you can 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 do ok in a tiny bit of cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant flower-of-an-hour in Tucson 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. If you wait any later than that and your flower-of-an-hour may not have a chance to fully mature. Starting your flower-of-an-hour indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Tucson is just an average the actual date of last frost changes from year to year. Half of the time in Tucson you get a frost after February 15 so just be sure to be ready to protect your flower-of-an-hour in the event of a late frost.

USDA Zone Info for Tucson

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 Tucson

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