En Español

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Wednesday - April 22, 2009

From: Tonto Basin, AZ
Region: Southwest
Topic: Problem Plants, Cacti and Succulents
Title: Eliminating agave roots in Tonto Basin AZ
Answered by: Barbara Medford

QUESTION:

Greetings Mr. Smarty Plants, from Tonto Basin, AZ! We have numerous mature (huge!) Agave Americana plants here, and have, until recently, enjoyed them. However, we are now ready for a drastic landscaping change. We're in the process of cutting them down, and would like to know if there is any way to kill the trunk on these plants. Our experience has been that if there's a minuscule section of root remaining in the ground, countless "pups" will eventually re-appear. As we would like to completely and permanently eliminate the ones that grow right next to our house, we are asking about killing the root. Thank you in advance for any help you can provide! Happy gardening!

ANSWER:

While we hate to recommend herbicides, you are correct that a small piece of root will generate fresh agaves, just what you don't want right now. We know you don't want to hear this, but digging them out with a good sharp shovel is the best way to begin. And disposing of them is going to be tough, too. Please don't put them in the compost pile, those thorns can last forever. A long-handled shovel, long heavy leather gloves and maybe heavy pruners to kind of cut the job down to size are going to be necessary. The best suggestion for cutting them down and keeping them down that we have found so far is to get some glyphosate herbicide and a few disposable sponge brushes. Don't go wild with this, because you want that area to be hospitable to your new landscape, so no spraying or drenching the soil. When you have removed all the root you can by manual (as in labor) techniques, make a clean slice across the remaining root and, within 5 minutes, paint that open wound with the glyphosate, full strength. You have to do it right away, because the agave, like all other survivors, will quickly move in to heal that cut over before the herbicide can get to the rest of the root. You will still get pups popping up over time, and waiting a while before you put in the raised beds is a good idea.

And, lesson for the future: When the pups pop, get them out while they're little. Get it all out with the same sharp shovel if you can, and do the paint job on any root remaining.

 

More Cacti and Succulents Questions

Are Agave Seed Pods Poisonous
September 27, 2010 - Are the seed pods, found in clusters, hanging from century plants(agave) poisonous to kids or dogs? They are large, light green, and shaped like fat bananas.
view the full question and answer

Branches of yucca being blown down in Torrance CA
August 19, 2010 - I have a Yucca tree about 30 ft tall. Lately when the wind picks up in Torrance we have had about 3 branches fall out of the tree. Can you help me with this. I don't want to cut all of the branches...
view the full question and answer

Blue agave with freeze damage in Lockhart TX
March 16, 2011 - I recently planted a blue agave plant, and 4 days after I planted it the temperature dropped to 20 degrees at night. The plants are still alive but 75% of the outer limbs turned brown. What do I do wi...
view the full question and answer

Source for DNA sequencing of Opuntia species
March 04, 2014 - Hi Mr. Smarty Plants, I am trying to do a Opuntia speciation study, and rather just identifying the species by morphological comparison, I would also like to go a little deeper by comparing the DNA...
view the full question and answer

Dying cactus plants
December 16, 2007 - Two large cactus plants on the grounds of our condominium complex have begun to turn yellow and appear to be dying. A "staple" of our landscaping, this is the first year that they have developed th...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center