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

Identification of green succulent plant with red tubular flowers
October 08, 2007 - Hi there, i have this plant which is green,leaves are succulent, and these red tubular little flowers about an inch long grow rampantly all summer. i wanna know what it is called as i take cuttings a...
view the full question and answer

Non-native jade plants and spider plants beneath Mayberry tree in Bay Point CA
October 15, 2013 - I have a fruitless Mayberry in my back yard that's about 50/50' can I plant jade and spider plants under it? The tree is very healthy.
view the full question and answer

Debugging and Preserving Dried Cholla Cactus
January 04, 2014 - Hi. Recently found an intact skeleton of a cholla cactus. I want to Bring it in our house. Are there any dangers associated with this, like bugs inside the "branches?" how would you suggest I prese...
view the full question and answer

Propagation of Agave americana by seed
July 11, 2007 - Dear Mr Smarty Pants, My Century Plant is fulfilling its one wish and blooming flowers from its massive stalk. Although I am very sad to see it go, it is certainly a sight to behold. This plant, ...
view the full question and answer

20 years to bloom
May 02, 2007 - My girlfriend and i have come up with an interesting question, we were wondering if there is a plant in existance that takes over 20 years to bloom, and how many different kinds (if any) there are? We...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center