One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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 first chance to plant lobelia in Tucson can be determined by referring to the USDA zone info.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Lobelia can survive in a bit of cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant lobelia in Tucson is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant lobelia and expect a good harvest is probably October. Any later than that and your lobelia may not have a chance to really do well. Starting your lobelia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Tucson the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Tucson may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Tucson there is a last frost after February 15 be ready to cover your lobelia in the event of one of those late frosts.

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.