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
4 ratings

Sunday - December 20, 2009

From: Bay Point, CA
Region: California
Topic: Non-Natives, Compost and Mulch, Poisonous Plants
Title: Could ammonia harm poisonous, non-native oleander in Bay Point CA
Answered by: Barbara Medford

QUESTION:

Could ammonia harm my Oleander plant? I have been spraying ammonia under it to keep neighborhood cats from using the soil under the plant as a sand box. If so, do you have any suggestions as to what I may use instead? Thank you.

ANSWER:

Ammonia is a compound of one part nitrogen and three parts hydrogen. Household ammonia or "ammonium hydroxide" is combined with water, with usually only 5 to 10 per cent of the resulting product being ammonia. Since both nitrogen and hydrogen are already in the environment, and nitrogen, at least, is beneficial to the soil, it is unlikely that it is going to cause any damage. We wouldn't recommend spraying it directly onto the plant leaves, but it shouldn't harm the dirt or the roots.

If we may take this opportunity, we would like to remind you that the Lady Bird Johnson Wildflower Center is dedicated to the use, care and propagation of plants native not only to North America but to the area in which the plant is being grown. Nerium oleander is native to Africa, Asia and and the Mediterranean. We realize it is widely used in California, but would like to point out one other  characteristic of oleander that may be more important than whether ammonia will harm it. Nerium oleander is one of the most poisonous plants known, with all parts of the plant being toxic. Ingestion of just one leaf can cause heart attack and death. Some of the poisons it contains are cardiotonic glycoside (oldendrine), prussic acid and rutin. Skin contact with the plant can cause severe dermatitis. Burning it will release toxins that can cause intoxication. We would recommend that it be carefully removed, wearing gloves and protective clothing, bagged and disposed of properly, NOT burned nor consigned to the compost pile, where the toxins would continue to be dangerous. 

Now, back to the dirt in your garden and the cats. Rather than spraying ammonia or some other aromatic liquid on the dirt, try a good heavy mulching with shredded bark mulch. Cats don't like scratching in that, its fragrance will alleviate some of the urine smell which is attracting the cats back to the same place, and it will enrich and amend the soil. 

 

More Poisonous Plants Questions

Poison ivy? vine in NJ
July 30, 2012 - I have a vine growing among some vegetation in my backyard. It has a leaf with 3 "points" with ridges along its edges. The smaller leaves are reddish which is why I thought poison ivy but definite...
view the full question and answer

Problems with shrubs by pool in Bethesda, MD
February 24, 2012 - We are trying to grow Otto Luyken Laurels by a pool and doing okay, some brown spots on leaves, but not many. Also have Arbivatea beside the pool about 3 feet from the edge of the pool. They have a l...
view the full question and answer

Toxicity of Fan Tex Ash tree to horses
July 22, 2012 - Is the Fan Tex Ash tree toxic to horses?
view the full question and answer

Identification of bush/vine with purple berries
August 09, 2014 - I was clearing fence line and came across this plant it looks like a Bush but underneath grows like a vine it has long broad leaves that reminded me of Polk salad but it grows berry clusters the berri...
view the full question and answer

Poisonous thorn in Marion NC
May 16, 2010 - Yesterday my son got a thorn stuck in his foot. I removed it but his foot is still swollen and puffy today. What kind of plants have poisonous thorns?
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