En EspaŅol

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?


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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
1 rating

Monday - April 29, 2013

From: Pacific Plsds, CA
Region: California
Topic: Invasive Plants, Cacti and Succulents
Title: Runaway Agave Americana from Pacific Palisades CA
Answered by: Barbara Medford


We live near open space on Santa Monica Mountain State Park. Our Association planted non-native, invasive Agave Americanas all over the adjacent slopes, and we are trying to get the exploding pups and forest of mature ones removed, or controlled. Three are now sending up stalks. Can we prevent seeding if we remove the individual flower stalks before they dry and split open? The rhizomes are bad enough, but seeds could more easily spread to our precious park land. I'd much appreciate some advice. Thank you for all you do. We have seen Mrs. Johnson's works in our, and other states. Jill Bowman


We don't quite know how to tell you this, but not only is Agave americana (American century plant) native to California but, according to this USDA Plant Profile Map, it is also native to Riverside and San Diego Counties, which is close enough to be considered native to the area. We found no indications that it was considered invasive, but you might want to read this Dave's Garden Forum page with several negative comments on the dangers of trying to remove it.

In answer to your  question on taking down the bloom stalk before it seeds out, you can certainly do so, but you will miss quite a show if you don't let the bloom stand for a while. And, the plant is going to die anyway. Century Plants live for from 8 to 40 years (not a century) before they bloom and, once they have bloomed, they die. They have been storing up the energy to reproduce all those years and then they are done.

You didn't say what Association planted the agaves, but if they are on State Park land, it would be up to the management of that park to determine whether they were to be removed and how it was to be done.

Here are links to some previous Mr. Smarty Plants answers on removing an agave:

Removing the pups

Removing the mother plant

Reasons to remove an agave

Cutting the stalk off

Bottom line: Cutting down and destroying the blooming stalk will certainly prevent seeding any more agaves, but the pups around those plants are the main source of propagation for the plant. Attacking any of those projects means attacking the mature plants, which is going to be plenty tough.


From the Image Gallery

American century plant
Agave americana

American century plant
Agave americana

American century plant
Agave americana

More Cacti and Succulents Questions

Care of Spanish Dagger (Yucca treculeana) after blooming
May 27, 2007 - I live in Austin and have a 5 ft spanish dagger in my backyard. Now that it has bloomed and the flowers have withered in May, should I cut off the center stalk or will it bloom again from the same st...
view the full question and answer

Preserving the agave bloom for decoration from Sedona AZ
April 28, 2012 - I have an agave century plant which is starting to bloom. Is there some way I can preserve the flower as a decoration piece?
view the full question and answer

Survival of yucca plant mowed down in Oklahoma
April 15, 2009 - I have a yucca plant that came from a very old plant of my late father, and had transplanted it 6 years ago and it came back every year and bloomed. This morning I went outside and noticed my husband...
view the full question and answer

Are agaves really native from Pacific Palisades CA
April 30, 2013 - I just replied re agave issues, and mistakenly asked the source of your information. I see that you clearly noted it, apologies. I would note, however, that the Riverside area is very much a hot,...
view the full question and answer

Plants that are deer resistant for high desert climate in Utah
January 23, 2008 - We are building in a high desert climate in Dammeron Valley, Utah. We want plants that are both deer resistant and require little watering. Can you advise which plants (shrubs, flowers, cacti) that ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center