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

Tuesday - May 15, 2007

From: Austin, TX
Region: Southwest
Topic: Cacti and Succulents
Title: Root depth of opuntia
Answered by: Nan Hampton

QUESTION:

What can you tell me about the depth of roots of the opuntia? Does it vary with different varieties or is there formula to estimate the depth according to the mature size or to the culture - garden soil - wet or dry - etc ?

ANSWER:

As far as Mr. Smarty Plants knows, there is no magic formula to determine the depth of the roots of Opuntia spp. In general, the Opuntia cactus have tap roots with extensive shallow lateral roots. The size of the tap root and the lateral root expanse has to be correlated, to some extent, with the plant's age and size; however, environmental factors, such as abundance of water, soil temperatures, and CO2 concentration, also have a large effect on tap root depth and lateral root extension. For instance, a study of certain Opuntia species naturalized in Africa has shown that water stress increases the length of the tap root and reduces the size of lateral roots. In Opuntia ficus-indica increasing soil temperatures and CO2 concentrations cause the lengthening of tap roots.

You can read more about cactus survival strategies.

 

 

More Cacti and Succulents Questions

Need help with yucca palm in New York City, NY.
November 10, 2011 - I have had my yucca palm plant for almost 10 years. The bark has started to peel off although leaves seem fine. The second smaller separate yucca plant has half its bark and trunk gone. I can't see a...
view the full question and answer

Shriveling agave from Miami Florida
August 23, 2013 - Dear Mr. Smarty Plants, Most upset - My beautiful agave (wish I could have submitted an image) has stared to misbehave. The once first liquid filled leaves, are starting to look more like the skin ...
view the full question and answer

Protecting agave pups in San Antonio
April 23, 2013 - I would like to share the soon to happen bloom of two century plants on my property; they are sisters planted at the same time. I am sad to know they will die but will do all that I can to protect the...
view the full question and answer

Foundation plants for Albuquerque.
July 01, 2012 - Hello, I live in Albuquerque. I am looking for some native/xeric low water usage plants for foundation plants for my home. They will be foundation plants for a two story home that has a large ponde...
view the full question and answer

Cochineal bugs on cactus
November 18, 2008 - Mr. Smarty plants. I have purple prickly pear cactus that are developing small white flake like spots, mostly where the thorns would be. Why is this happening and how can I cure it?
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