En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Getting rid of algae on dirt and patio

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 - January 12, 2011

From: Gilroy, CA
Region: California
Topic: Compost and Mulch, Diseases and Disorders
Title: Getting rid of algae on dirt and patio
Answered by: Nan Hampton

QUESTION:

Algae and on patio and dirt, and how to get rid of same?

ANSWER:

I'm guessing you meant to say "algae and (moss) on patio and dirt".  Am I right?  If you have either one in such a situation, you usually have both.  The reason they are growing there is that they are experiencing continuous moisture and very little sunshine.  Those are two of the major requirements for algae and moss to grow.  First, we will talk about your soil.  Poor drainage is very likely a major factor with soil that remains moist.  If your soil is very dense and compacted, aerating it and adding compost and/or mulch to it will improve its drainage.  The University of California Cooperative Extension Service has an article, "Moss and Algae Do Well in Wet Weather and Poorly Drained Soils", that offers other suggestions for eliminating algae and mosses which include applications of copper sulfate, ferrous sulfate or ferrous ammonium sulfate.  Another recommendation from the Yard Doctor: Central Northwest suggests using sodium hypochlorite (or copper sulfate) in a 1% or 2% solution to spray the area.

If you Google the terms "eliminating algae from patio", you will get lots of suggestions for removing algae from patio bricks which include power washing, dilute bleach solutions and algaecides.  Again, changing the elements that cause the problem (poor drainage and too much shade), are important in order to keep the algae from returning.  How you remove the algae depends on the size of the area, the intensity of its growth and what plants or structures are nearby that might be impacted by the treatment.  Here are a couple of sites that have suggestions:  from Desmesne and from the Royal Horticultural Society in the UK.  You can consult a reputable local nursery or home supply store to find the most effective and ecologically responsible algaecides.  I would also suggest you contact your Santa Clara office of the University of California Cooperative Extension Services for suggestions for removing the algae.

 

More Compost and Mulch Questions

Native Grass is Falling Over
November 09, 2011 - Hi Mr. Smarty Plants, I've tried to find this answer but am stumped as to the cause. We live in Fredericksburg, TX and have several different tall grasses, Yellow Indian grass, Little Bluestem, wire...
view the full question and answer

Berms to hold water around roots
December 05, 2008 - I planted new flower beds this November. There are currently dirt 'berms' around each plant - creating a well for water to seep into the immediate plant area. How can I keep these berms from erodi...
view the full question and answer

Native plants for clay soil in Lathrop MO
March 21, 2011 - My family just moved to the north Kansas City, MO area and would like to know what native species, both perennial and tree, will do best in the clay soil. It has already proven problematic as we have ...
view the full question and answer

Destructive landscape crews in The Woodlands TX
October 20, 2012 - Hi. We need help. We recently moved to a house where landscape crews have been blowing away the leaf litter from the front yard for many years. The underbrush was also cleared long ago. The result...
view the full question and answer

Replacing mature Arizona Ash trees in Austin
August 26, 2011 - Mr. Smarty Plants, I have 2 very large, very old Arizona Ash trees in my yard. I want to remove them and replace them with something like Cedar Elm or Chinquapin Oak. The problem is that they are t...
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
© 2014 Lady Bird Johnson Wildflower Center