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
3 ratings

Monday - January 16, 2012

From: Austin, TX
Region: Southwest
Topic: General Botany, Soils
Title: Changing the pH of the soil
Answered by: Nan Hampton, Barbara Medford and Joe Marcus

QUESTION:

Hi, We have a job that has mostly Texas native plants on it. The architect is wanting to drop the pH levels of the soils to acidic levels that we don't feel is good for the plants and the area. Could you please contact me so I can send you the plant list and get your recommendations for the soil pH for the various plants? Thanks.

ANSWER:

The soils in Austin/Travis County are highly alkaline and the native plants of our area thrive on this soil. So, the fact that the architect wants to acidify the soil says to me that he intends planting non-native cultivars or, at least, plants not native to this part of Texas.  They will look beautiful for a short period of time until the pH of the soil begins to go up as the acidity of the soil declines—and it will definitely decline.  The soil will gradually return to its original alkalinity, probably within just a couple of years, and the acid-loving plants growing there will begin to sicken and probably die.  Additionally, acidifying the soil would likely have an adverse effect on the native microfauna living in it that are essential for healthy plant growth.  The plants native to Central Texas are not going to do well in the acidified soil and the non-native plants that start out doing well are not going to do well for very long as the acidity weakens.

You will find that the majority of the plant species pages in our Native Plant Database contain a description of the soil requirements for the plant under the heading "Growing Conditions".  For instance, on the pages for both Sophora secundiflora (Texas mountain laurel) and Cercis canadensis var. texensis (Texas redbud), under GROWING CONDITIONS, you will find:  "Soil pH: Alkaline (pH>7.2)."  You can search for the pH values of the native plants on your list in our Native Plant Database.  It is easiest to search by the plant's botanical name.  If the pH level isn't given for the plant you are looking for, then your best bet is to search the internet using the plant's botanical name.

Our recommendation to you is to use plants that are native to Central Texas.  Their pH requirements will be met by the existing soil and there will be no need to acidify it.

 

More General Botany Questions

Genetics of Anemone berlandieri flower colors
December 01, 2010 - Anemone heterophylla or Anemone berlandieri, Genetics. Is the variation in the flower color due to Genetic Incomplete dominance or Codominance? The same codominance seen in carnations.
view the full question and answer

Consumption of carbon dioxide from South Korea
December 07, 2011 - I am curious about what flowers consume CO2 for growing (especially 1-year life flower). Thanks.
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

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

Water Use Versus Soil Moisture
October 14, 2014 - In the Native Plant Database, under Growing Conditions what is the difference between water use and soil moisture? Sometimes they seem contradictory.
view the full question and answer

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