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
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 Diseases and Disorders Questions

Leaf drop from live oaks in mid-summer
July 08, 2013 - We have a live oak that is starting to drop a considerable amount of leaves here in early July in Cypress Texas. Its a mature tree with a base diameter of 12-14" and 25-30' tall. We live in a subd...
view the full question and answer

Old oak tree dropping leaves in Hazlet Township NJ
July 08, 2013 - I am 84 yrs old and have a 50 year old pin? oak. No more acorns, but the leaves are falling in clumps and are still alive. Every day I fill a huge garden bag with them. I live on a fixed income and...
view the full question and answer

Chlorotic disease in scrub oak from Katy TX
July 04, 2013 - Please tell me how to treat my scrub oak as it has chlorotic disease. Parts of the tree are fine and others have yellow leaves. It has not been injured in any way.
view the full question and answer

Young oak damaged by falling tree from San Diego TX
June 27, 2012 - My neighbor's Palo Blanco tree was struck by lightning and fell over our fence and on to a young oak tree in our yard. We waited a few days to see if the neighbor would offer help, but he never did,...
view the full question and answer

Non-native Chamaecyparis pisiflora turning brown in Fuqua-Varina NC
December 10, 2012 - I have a "Soft Serve False Cypress" Chamaecyparis pisifera'Dow Whiting PPAF, that has only been in the ground for 6-7 months. I just noticed that the branches and leaves are starting to die, turni...
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