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
1 rating

Sunday - May 24, 2009

From: Dallas, TX
Region: Southwest
Topic: General Botany
Title: Plants for soils with extreme pH values
Answered by: Chris Caran and Nan Hampton

QUESTION:

I am doing a project on acid and alkaline on the ph scale but all I can find is a range of 5.0 to 8.0. Do they have plants in the range of 8.0 to 14.0 or 1.0 to 5.0? If not, why is that? If so, what are they?

ANSWER:

Using the standard method of testing specified by the Natural Resource Conservation Service (NRCS), part of the US Department of Agriculture (USDA), most soils do indeed yield pH values in the range of 5.0 to 8.0 or slightly higher, although soils in some parts of the world commonly have higher or lower values.  This pH range is related to: 1) the stability of common soil-forming minerals; 2) a soil's capacity to retain and release moisture and nutrients; 3) the processes by which certain hazardous materials become concentrated in the soil; 4) the viability of many disease organisms (especially fungi and bacteria) affecting particular plants; etc.  It is for this host of reasons that soil pH is an important factor in plant health.

Few plants grow in soils with pH values far outside of this "optimal" range, although there are a few specialized plants and plant communities that require somewhat higher or lower pH conditions.  I doubt, however, that there are any vascular plants that normally live and reproduce in soils with pH values below approximately 3.0 or above approximately 9.0, although some non-vascular plants may tolerate values slightly outside of this range.  Some "extremophyle" microbes (certain bacteria and photosynthesizing cyanobacteria, etc.) and even a few invertebrate animals live in waters with pH values of 2.0 or below or above 9.0.

There are, of course, regional and local variations in soil pH, which are primarily related to the nature of the underlying bedrock and sediment, seasonal variations in precipitation and temperature, soil drainage (i.e., persistence of water saturation), etc.  The pH values for soils in any given area therefore generally fall within a relatively narrow range.  Naturally, the plant life native to each area is adapted to grow in soils with those particular pH values, at least in part.

Here is a list from Colorado State University of acid-loving plants, some of which have ranges down to pH 4 and more information from University of Hawaii about why acid soils are not favorable for plants.

You can find more information by googling "acid tolerant plants" and/or "alkali tolerant plants".

 

More General Botany Questions

Effectiveness of house plants for removing household air pollution
January 30, 2006 - I have heard that there is a combination of house plants that will increase the oxgyen in your home. Could you please tell me the names of these plants? I think there are a group of four of them. ...
view the full question and answer

Native subarctic plants
March 26, 2008 - I'm doing a project on subarctic things and I have to have subarctic plants in it. I need to know a few and about them. Can you help?
view the full question and answer

Manzanita struggling in CA
March 01, 2012 - I live in Monterey, CA and I have had a manzanita (either Dr. Hurd or Mt. Hood) growing successfully in my yard for about 4 years. This fall all the leaves turned brown and brittle. I am not sure if d...
view the full question and answer

Variation in leaves for Vitis mustangensis
May 17, 2012 - Hi, I am doing a sculpture of a mustang grape vine in limestone. In seeking a good leaf image I notice that there are both roundish shaped leaves and highly divided or "fingered" shapes on your sit...
view the full question and answer

Are Native Cultivars As Beneficial to Wildlife?
September 02, 2015 - I am working on adding more native plants to my small acreage. I would like to know if using a selection or cultivar of a native species is as likely to have wildlife benefits as using a randomly prop...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center