En EspaÑol

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

Wednesday - July 13, 2011

From: Austin, TX
Region: Southwest
Topic: Compost and Mulch, Watering
Title: Possibility of hydrophobic soil in Austin, TX.
Answered by: Jimmy Mills

QUESTION:

I believe I have an area in my garden with “hydrophobic soil”: no matter how much or how slowly I water, it just beads up and rolls off and the soil beneath remains cement dry and powdery. In my reading on the internet, it suggests using a very dilute solution of soapy water (1 tsp soap to 5 gallons of water), to decrease the surface tension, but it seems this is only a temporary fix for the next watering. I also read that bagged bark mulches can be the cause (I have been using bagged native Texas bark for several years. What are your thoughts?

ANSWER:

I must admit that I hadn’t heard of “hydrophobic soil” until I read your question and started looking on the web for an answer. How large an area are we looking at? This may influence the remedy that you choose.

Lets start by looking at soil in general. This article from Bachman’s Gardens gives a good overview of the nature of soil, its components, and the role of soil texture (ie particle sizes) in determining its water holding capacity. Generally, sandy soils allow more percolation than soils with finer particles.

This link from the University of Florida answers the question that I had:”What is hydrophobic soil?, suggests a possible cause, and offers mulching as a remedy.

A link from treesfoundation.org  (starting with the third paragraph) describes how hydrophobic soils can be the result of wildfires.

One possible remedy for hydrophobic soils is the use of non-ionic surfactants on the soil (University of North Carolina).

This forum from Gardenweb.com has comments from those who prefer the use of surfactants (soapy water) as well as those who propose changing the texture of the soil eg. adding mulch or compost and spading in the organic material.

I am partial to the latter, depending on the size of your garden plot.

Another source of information is the folks at the Travis County Office  of AgriLife Extension.



 

More Compost and Mulch Questions

Transplanting adventitious shoots of a mountain laurel in San Antonio
August 20, 2009 - Is it possible to transplant branches (shoots) growing from a mountain laurel that was chopped down? Some are two years old and several feet tall (but not yet blooming) and some as small as a foot. ...
view the full question and answer

Will recycled tire mulch harm butterfly larvae?
December 05, 2012 - I discovered orange butterfly larva in the hardwood mulch under my Turk's Cap. Will it harm the larva if I switch over to recycled tire mulch?
view the full question and answer

Transplant shock in Mountain Laurel in San Antonio, TX
June 03, 2011 - I planted a 2 ft. tall Texas mountain laurel a month ago. Some of the leaves have turned very yellow and some of them are falling off. The plant doesn't look real healthy in general. I did add s...
view the full question and answer

Fast-growing vine for cinder block wall in Albuquerque
July 26, 2010 - I live in Albuquerque, N.M. and have a cement/cinder block wall and was wondering if there is a vine I can plant which will be easy to grow, grow fast and cover my wall without any type of help like a...
view the full question and answer

Plants for clay soil in Leavenworth IN
October 02, 2009 - I live in south central Indiana; the soil is very bad clay, either hard as a rock or mud. I have made several raised beds but am still having problems with plants rotting. What types of plants work he...
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