Explore Plants

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
    
 

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

Spineless prickly pear from Lago Vista TX
April 30, 2012 - We visited Lady Bird Johnson Center yesterday. I was impressed with the spine less prickly pear cactus. Is it a native or a hybrid?
view the full question and answer

Life span of the century plant (Agave spp.)
June 17, 2009 - I have a beautiful century plant that is blooming. what will happen once the bloom is done? What is the life span of the plant?
view the full question and answer

Removing faded flowers from plants in Georgetown, DE
July 28, 2012 - I bought a chamase rose quartz that was in bloom. now the buds are dead, should i remove them or just leave them on the plant. they wont just fall off. and the tips of the plant has new growth.
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

Yuccas and prickly pears for Warren MI
February 11, 2009 - What type of yuccas and prickly pears will survive in the Detroit, Michigan area? Also, can I grow Santa Rita prickly pear in a pot?
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.