Native Plants

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Friday - March 04, 2011

From: Austin, TX
Region: Southwest
Topic: Cacti and Succulents
Title: Loss of agaves to freezing weather in Austin
Answered by: Barbara Medford

QUESTION:

Dear Mr. Smarty Plants: I live in Austin and lost all my agaves in the subfreezing weather this winter. Around town, I've noticed some agaves that seemed to tolerate the cold just fine and other that are totally ruined. Can you recommend the species that can handle the cold (as well as our summer heat), and advise what final size they are? Thanks!

ANSWER:

We first checked with Julie Krosley, a staff member in charge of the Gardens at the Lady Bird Johnson Wildflower Center on whether agaves on the Center grounds had been damaged, also. Here is her reply:

"Most of our agaves have had leaf damage, but none have totally succumbed. It is hard to know if the agave in question was native to the area or not. I would suspect that some of the South Texas species would have frozen. If she had one in a pot that was hardy to this area, I bet it would come back."

Since we don't know if yours were of South Texas or even Mexico origin, we will answer your original question by finding and listing plants of the Agave genus that are shown to be native to this area. The temperatures we had a couple weeks ago were not the first freezing temperatures in Central Texas nor will they be the last. A plant native to this area already has learned that. Succulents (such as agaves) are more susceptible to damage from freezing, because they have a lot of fluid in their cells. When water freezes, it gains volume, and can rupture those cell walls. Please read this article from the Mohave County, Arizona Cooperative Extension on Freeze Damage in Plants.

Searching our Native Plant Database for agave, we found 14 native to North America, and 9 native to Texas. We found exactly one, Agave americana (American century plant), that is shown on the USDA Plant Profile map for that plant as being native to Travis County. These maps are not always up to date, and sometimes include plants cultivated in an area to which those plants are not native. Nevertheless, the fact that all the other agaves native to Texas grow only in far West Texas or South Texas is a pretty good indicator that agaves may not be hardy to this area.

Follow the plant link above to read all about the height and growth characteristics of Agave americana. Perhaps planting in a more sheltered spot, where warmth from the sun might soak into walls behind the plant, might provide enough warmth to get a new agave through cold nights. There are no guarantees about Texas weather or the plants that grow in it.

Pictures of Agave americana from Google