Rent Shop Volunteer Join

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

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

Mountain laurel with fasciation
July 24, 2014 - My Texas Mountain Laurel bush has developed several "crested branches." What causes this, is it harmful & how do I get rid of them??? Thank you!
view the full question and answer

What happens when plant shoot apex is removed from Nashville TN
April 23, 2011 - What happens to the plant when a shoot apex is removed?
view the full question and answer

Yellowing of palm tree leaves
May 14, 2008 - I want to know about palm trees. The leaves are turning yellow.
view the full question and answer

How is native range changed in the scientific record?
March 28, 2011 - I am accessioning Pachysandra procumbens for the Baker Arboretum. These plants were made from cuttings of a native stand here in Warren County (Western KY). How does the record get amended to...
view the full question and answer

Help with Science Fair project from Danbury CT
January 12, 2012 - Hello Mr Smarty, I was going to do my science project on weevils and their impact on milfoil. The weevils are in hibernation until spring and my project is due in mid-Feb. Any suggestions on a simil...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.