• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

Using Laurel Leaves for Mulch?

 
                          
Posts: 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi,

I got a place a few months ago with a huge laurel hedge in the front yard and I've been thinking of getting rid of it. It takes up too much space that could be used for better things and I don't want to have to be pruning it every 5 minutes. So someone suggested the hugelkultur option of taking it down and using the pieces as part of a raised bed, I've also though of using the clippings as mulch in some of my other beds . . . all well and good until I started poking around and found the following info about laurel containing cyanide, not too good for anything around edibles, I'm thinking.

Found naturally in the stones of cherries, plums and peaches, the cores of apples and the leaves of the laurel plant, cyanide evolved as a plant protection mechanism of grazing animals (interestingly, a number of bacteria, fungi and algae are also found to produce the chemical). Ingestion of moderate amounts of these natural substances cause headaches accompanied by mild heart palpitations, more than enough to steer animals – two-legged or four – clear. However, the Middle Eastern people of ancient times made the discovery that the distillation by evaporation of laurel leaves produced lethal concentrations of this innocent plant product.

The other important thing you need to know about Laurel is that all its
parts are very poisonous. Be careful when you come to dispose of prunings.
When it burns, it gives off cyanide; similarly, if shredded, there will be
cyanide in the sappy vapours.
Ignore people who say they've always burned/shredded it without any trouble:
they've been lucky so far. A friend of mine merely trimmed his Laurel hedge
lightly, and his arms became very red and covered with blisters. It's
really not worth the risk.


Does anyone have any other info on this?
 
              
Posts: 40
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I am very glad I saw this post.  I have a bunch of laurel wood in my wood pile.  That would have been a very bad thing to burn indoors.
 
Kelda Miller
Posts: 769
1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Ditto, I've heard that about not burning laurel: not good.

But in a hugelkulture? I think that would be okay. Just a gut feeling.
But people make great compost out of apple cider pressings, that contains cyanide via the apple seeds. And it won't harm plants.

I guess the question is more 'how does cyanide move around in the soil?'. if it's taken up by plants and put in fruit/greens then there's a problem
 
Leah Sattler
Posts: 2603
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
just a thought. If the cyananide produced in plants such as laurel as well as cherry,peach and almonds were not broken down in the soil, areas where these were grown would be slowly poisoned. The plants make the chemicals they contain by drawing the components from the soil where they eventually return presumably to be broke back down into their original form. I know that some fungus and such can break down cyanide but I also know there are different chemical compositions some of which may be more easily assimilated back into the soil. very interesting question.
 
Arthur Lee Jacobson
author
Posts: 23
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
First, various plants are called laurel. My book Trees of Seattle indicates 8 genera and 10 species so called. Only one genus (Prunus) has the "cyanide" (cyanogenic glycosides that break down to release hydrocyanic acid). Guessing, for the sake of discussion, that the "huge laurel hedge" may be Prunus Laurocerasus, then yes, it has cyanide, as do its relatives. In my experience of decades, I shrug "big deal." I had read that if I took a leaf of this plant, and squished and mangled it to release its poison, and put it in a jar with an insect, that I would thereby kill the insect. After several hours of waiting, I let an annoyed bee fly free. I prune this species of laurel every year --as do thousands of others-- without any ill effect. I burn the seasoned (dry) firewood regularly. That said, I admit that some people, of more sensitivity, and not dressed so as to protect their skin, may, in the right atmospheric conditions, get a modest rash from it. I write this because the number of plant saps or chemicals that cause dermatitis in one person or another is vast. But numerous garden trees and shrubs are more worrisome in this regard, including juniper. Finally, the fully ripe plump black cherries of Prunus Laurocerasus are edible, but do spit out the pits just as you should cherry pits, apple seeds and the like. The idea that laurel leaves would be unsafe as mulch is ludicrous. I have composted them and mulched with them for decades, and my lush thriving garden bears silent testimony to their safety. You readers can "ignore" me if you care to. I aver that if you take the time to review facts and evidence calmly and logically, rather than relying on knee-jerk emotions of fear, then you will end up confirming my experience.
Arthur Lee Jacobson
 
Dave Boehnlein
Posts: 294
Location: Orcas Island, WA
3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Yeah, I'm with Arthur on this one. Although evergreen, remember that those laurel leaves are always falling off and hitting the ground. With the number of laurels in landscapes around Seattle you would think it would look like a desert if they caused problems. That clearly isn't the case.

I'd say wear long sleeves, but don't hesitate to whack that hedge and put the products to good use.

 
Leah Sattler
Posts: 2603
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
As I suspected. Good info for future reference!
 
Susan Monroe
Posts: 1093
Location: Western WA
1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Just don't feed the prunings to livestock, to which they are poisonous.

And don't feed them to children, for the same reason.  I was recently reading that eating a single peach leaf can kill a small child.

Sue
 
paul wheaton
steward
Pie
Posts: 19440
Location: missoula, montana (zone 4)
bee chicken hugelkultur trees wofati woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
SueinWA wrote:
And don't feed them to children, for the same reason.  I was recently reading that eating a single peach leaf can kill a small child.


Sunnuffa ....  what the hell is in a peach leaf that is so toxic?

 
Susan Monroe
Posts: 1093
Location: Western WA
1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
"...what the hell is in a peach leaf that is so toxic?"

This isn't the article I had read a while back, but the info agrees with it.  From http://www.forestmanagementcenter.com/PDF/PoisonousPlants.pdf ;
"isturbingly-Common Poisonous Plants"


"Peaches, Cherries and Apples all have toxic components. All parts of the cherry and peach trees, with the exception of the edible fruits, contain cyanide-producing compounds that are released when cherry or peach seeds, bark, and leaves are eaten.  Children have died from eating the seeds, chewing on peach twigs, and making " 'tea' "

Many, many things we eat are quite toxic if the wrong part is eaten:  potato sprouts and green skins, rhubarb leaves, are two of them.

Many Americans don't teach their children anything about anything. Ignorance is rampant today.

But when I was a kid in SoCalif, my mother grew castor bean plants every year.  She told us when we were small:  "That plant is poisonous and will make you very sick. Don't chew on the leaves and don't eat the beans."

When neighbor kids came over, we told them: "That plant is poisonous, don't eat those beans, they'll kill you."  Nobody ate the beans.  We used them for tic-tac-toe, for counting, as markers for bingo cards, slingshot ammo, and lots of other fun things, but we didn't eat them. No one got sick and no one died.

Sue
 
tel jetson
steward
Posts: 3352
Location: woodland, washington
75
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I was spreading a pile of tree service wood chips yesterday.  there was a lot of cherry laurel in the pile.  the vapor rising out of the pile as I filled wheel barrows burned my nose and left me short of breath last night and this morning.  I can't say for sure that the cherry laurel is to blame, but it seems plausible.
 
rose macaskie
Posts: 2134
1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Cynide does get cooked out of things, some how reduced by cooking. Bamboo shoots are full of cynide and have to be cooked iin the right wayundercooked they would still have cynide in them. .
  I  have read that if you plant a almond near a peach then the almond may be fertilised by the peach tree and the almond seed be too full of cynide. Do seeds develop in the way the embrio they encase would grow or under the direction of the genes off the plant that they hang off.  I suppose the placenta and such grow with the babies genes not with the mothers cells.
  i do miss leah Satler, maybe it is just that the photo of here is so cheerfull. I got interersed in the personality of the people in the thread at first but now i dont do it much any more, May be I am writing more and so dont spend much time thinking about the people on the thread. agri rose macaskie.
 
Jack Shawburn
Posts: 230
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Susan, Excellent article! - Thanks - saved it...
My concern with these plants is when used in compost or as a chipped mulch.
I keep Oleander away from the veg and fruit and nut tres in general,
but what about others in compost and being used in veg garden eventually...such as Chinaberry that grows everywhere.
I have not come across any articles that may explain the breakdown of toxins in compost.
 
Jack Shawburn
Posts: 230
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Did a quick search on Wiki !!!
wow ! - please read about Red Beans !
http://en.wikipedia.org/wiki/List_of_poisonous_plants
 
bg carter
Posts: 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have two huge laurel hedges and have been pruning, chipping/shredding, mulching and burning for years.

I have never had any bad effects and one big beneficial one and that is from the mulch. I put the chipped and shredded mulch in many beds. It works better for weed and pest control than anything else I have used. Think about it. NOTHING eats a Laurel....well, except for slugs. The beds where I use the Laurel are the healthiest ones I have.

I don't know which genus of Laurel I have but it prevalent in the Pacific Northwest. All over Seattle and Western Washington.

Also, I have many families of Robins who return year after year to nest in these Laurels (I only trim before or after their nesting season) and they seem perfectly fine.
 
Clare hughes
Posts: 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you for posting this information about Laurel.
A friend of mine recently told me it wasn't good to burn or compost Laurel. So yesterday, when we had to brutallly cut back a huge laurel bush in our garden, I decided to Google it to check on the reasons why not to compost.
So glad I did!
And just to say, it also explains the small red itchy blisters that have appreared on my finger. I did use gardening gloves for collecting up the leaves & branches, however there was a small hole in one of the glove fingers and now I have a nasty red blistered patch as a result!
Be warned!
 
Michael Cox
Posts: 1556
Location: Kent, UK - Zone 8
42
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Clare - we compost with laurel all the time, usually by shredding it first. I gets hot and breaks down really fast. No problems there.

Fresh cut leaves can 'burn' plants they are incontact with, killing grass in under 24 hours in our experience. Don't be afraid of it, just use it sensibly. And if you have a patch of grass to kill off you know what to use!
 
Peter Ellis
Posts: 1266
Location: Central New Jersey
34
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
How many people are familiar with the term "anecdotal evidence" ?

I am curious as to whether anyone can point us to some scientific research on the subject of safely handling and disposing of laurel.

As to notes about how someone has had no problems, but where they use the laurel the weeds and insect pests are way down - mmm - mm- evidence that the stuff is having a negative effect on weeds and insects doesn't ring any sort of alarm bell for you about WHY it is having such an effect?

 
Michael Cox
Posts: 1556
Location: Kent, UK - Zone 8
42
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
http://www.bt.cdc.gov/agent/cyanide/basics/facts.asp

Key Points:
Cyanide gas evaporates and disperses quickly in open spaces, making it less harmful outdoors.
Cyanide gas is less dense than air; so it will rise.

Cyanide is found in various forms in many plant species, including almonds (both the nuts and the plant). Most pips contain compounds that will break down into cyanide. Cyanide is found in most smokes, including cigarette smoke.

Ultimately, cyanide is an organic compound which will definitely either break down through composting or evaporate into the atmosphere. Yes, when concentrated it can be dangerous so be sensible - If you must chip or shred it make sure you do it on a windy day and don't transport shreddings in a sealed vehicle.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic