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?

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
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
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 Diseases and Disorders Questions

How to treat bark damage on oak tree
November 15, 2011 - I have an oak tree approx. 50 ft., live in austin, texas. the tree has dropped bark about 3-4 ft above ground, in a section of 4 inches by 8 inches, and the tree appears dark where the bark was. is ...
view the full question and answer

Watering oaks in Houston, TX.
June 07, 2011 - Our yard (Real County, TX.) has many oak trees. We never water these trees, but I wonder if you recommend watering during this extreme drought. The trees look very stressed and are covered in ball m...
view the full question and answer

Insect pests in Gaillardia aristata in Tennessee
August 22, 2008 - Dear Mr. Smarty Plants, I have a couple of 'Oranges and Lemons' blanketflower plants in a butterfly and hummingbird native flower garden that is the foundation planting of my house. They bloom prol...
view the full question and answer

Insects attacking Gregg's Blue Mistflower from Comfort TX
June 20, 2013 - I have a beautiful stand of Gregg's Blue Mist flower that have been attacked by an unknown insect. The new growth is curled and stunted and it is not flowering. I'm not alone..I've seen the Gregg'...
view the full question and answer

Problem with Quercus texana (Nuttall oak) in Alabama
March 12, 2014 - I have a 3" diameter Nuttall Oak that the builder planted when building the house. Last summer I noticed that several spots on the trunk were oozing sap (vertical approximately 1.5" long by 0.5" wi...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center