Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Thursday - July 04, 2013

From: Magnolia, TX
Region: Southwest
Topic: Diseases and Disorders, Cacti and Succulents
Title: Century plant leaves yellowing from Magnolia TX
Answered by: Barbara Medford

QUESTION:

The leaves on my large Agave/Century plant are turning yellow. The bottom leaves, touching the ground are dying. Plant is 5.5" tall, 6" across & approx 10 yrs old. Recently we put red mulch around the plant. Could this be causing it stress?

ANSWER:

There are 10 plants with the common name "Century" plant native to North America, of which 7 are native to Texas. None are native, nor even very close to, Montgomery County, in southeastern Texas. All are members of the Agave genus and, since your plant may not only be not native to your area, it may even be a hybrid or native to Mexico, which means it is not in our Native Plant Database at all. Here are three of the Texas natives, with maps for each from the USDA Plant Profiles, showing in which counties they are native:

Agave univittata (Maguey mezortillo) (Map) native closest to Montgomery County, in Kennedy and Starr Counties on the far southern tip of Texas.

Agave havardiana (Havard's century plant) (Map) native to to Jeff Davis, Pecos and Brewster Counties, in the West Texas Big Bend areas

Agave parryi (Parry's agave) (Map) native to Culberson, Jeff Davis and Brewster Counties, also in Big Bend Area

We mention these locations because we suspect the problems with your agave, whichever one it is, are cultural. Agaves are basically tough desert plants, accustomed to enduring intense heat, full sun and weeks without rain. For instance, here are the growing conditions for Agave havardiana (Havard's century plant), from our webpage on this plant:

"Growing Conditions

Water Use: Low
Light Requirement: Sun
Soil Moisture: Dry
Soil Description: Dry, rocky soils."

We have driven through Magnolia on our way to The Woodlands many times, and our impression of that area is that it is heavily forested, probably with acidic soils from all the leaves and pine needles that have fallen over the centuries, with more shade and more rain than this plant likely needs or can tolerate. This is why we always recommend the use of plants native not only to North America but to the area in which they have evolved because they are already accustomed to the sun, climate and soils of their native area. However, because we can't prove anything we have said, we will look for some research on what could be causing the yellowing and drooping of leaves.

Please read this previous Mr. Smarty Plants question for more information and possible fixes for your plant.

 

From the Image Gallery


Maguey mezortillo
Agave univittata

Havard's century plant
Agave havardiana

Parry's agave
Agave parryi ssp. neomexicana

More Cacti and Succulents Questions

Non-native hylocereus undatus for Austin
February 24, 2012 - Can we plant Hylocereus (Dragon Fruit) here in Austin, TX? We are going to have a large xeriscape bed and want to know what all we can put in it. We are new to Texas so we have no clue what grows here...
view the full question and answer

Semelparous: plant that dies after reproduces. Agave and bamboo.
May 15, 2007 - There is a term for a plant who lives its life (usually more than 2 years) sends up a spectacular flowering structure, and then dies. what is that term? a certain plant that falls into that category...
view the full question and answer

Can Joshua Tree yucca be grown in Denham Springs LA
December 31, 2011 - If planted in a patch of raised and well-drained soil and covered during heavy rains, would it be possible to grow a Joshua Tree yucca in eastern Louisiana?
view the full question and answer

Native plants for highlights in a cactus garden
March 12, 2008 - Hi, I'm looking for some groundcover (succulents or herbs), shrubs, and other perennials to plant along with the cactuses (20 or so) I got from the CDRI plant sale in Fort Davis. The most important ...
view the full question and answer

Prickly pear doing poorly on Long Island NY
December 27, 2012 - First, thanks for your reply on 11-3-12, re.Can a prickly pear cutting from Harker Heights, TX find happiness in Long Island, NY. The plants were set before a southern window in the attic, temp. ra...
view the full question and answer

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