Rent Shop Volunteer Join

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

Both large and small Century plants putting up stems from Cayucos CA
November 18, 2013 - I have a Century Plant that is sending up a stem. I am excited to see it bloom. I noticed that one of the small pups, about 4 inches tall, is also sending up a stem. I have not found a mention of pups...
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

New agave plants, offshoots of parent plant, transplanting
September 16, 2007 - I have different varieties of Agaves that are sending off new plants from the mother. Some have 1-2 and some have 6-7 plants. Is there a proper method for removing (cutting them a certain way) for t...
view the full question and answer

Replanting a blue agave in Rio Rancho NM
January 11, 2010 - I have acquired a Blue Agave, approximately 4-5 ft high. It still appears quite healthy. It was used over the holiday season for display purposes in a liquor store. Unfortunately, the root ball has be...
view the full question and answer

Prickly cactus in Williamson County, Texas
September 12, 2010 - Dear Mr. Smarty Plants, Can you tell me what species of prickly pear cactus we have here in Williamson County? I see two listed as being here in Texas. One is the Plains variety and the other is ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.