Yew Tree Toxicity Question

Description of your first forum.

Yew Tree Toxicity Question

Post by Les Hazlewoo » Fri, 18 Mar 2011 18:40:28



I'm posting this in the hope that someone is able to answer a question
about using water that is contaminated with berries and possibly leaves
from a Yew tree.

The shed on my allotment is underneath the branches of a Yew tree which
lies on the boundary of the allotment site. Since the autumn I've been
saving run-off water from the shed roof to use on my vegetables.
However, quite a few berries (and possibly a few leaves) from the Yew
tree have been washed into the water tank. I realise now that I should
have anticipated this, and strained the water before it went into the
tank - but after-sight is wonderful thing !!!

I've read that Yew leaves are toxic and poisonous to many animals.  Also
that the red "avril" part of the berry is not toxic, but the seed inside
the "avril" is extremely poisonous.

Its early in the growing season, and I haven't used any of this water
yet, but is it safe to do so, ie:

a) Is is safe to eat vegetables that have been watered using this
contaminated water ?

b) Will the leaves / seeds continue to contaminate the soil, or will the
toxins in them break down ?

c) Does it make any difference if I strain the water before using it ?

I realise these might be quite difficult questions to answer, but I've
got a "winter's worth" of saved water that I'd really like to try make
use if rather than throw way.

Many thanks in anticipation ...

Les Hazlewood

 
 
 

Yew Tree Toxicity Question

Post by Pat Kiewic » Fri, 18 Mar 2011 20:53:26


Les Hazlewood said:

Quote:

>I'm posting this in the hope that someone is able to answer a question
>about using water that is contaminated with berries and possibly leaves
>from a Yew tree.

<snip>

Quote:

>Its early in the growing season, and I haven't used any of this water
>yet, but is it safe to do so, ie:

>a) Is is safe to eat vegetables that have been watered using this
>contaminated water ?

I really can't imagine that they wouldn't be safe to eat.  (Washing them
with clean water before eating is probably something you already do,
I assume.)

Relax! There's far more risk just in travelling to your allotment. Even the
manure you might use in your Garden has more potential to harm you.

Quote:

>b) Will the leaves / seeds continue to contaminate the soil, or will the
>toxins in them break down ?

Certainly the toxins break down.  I've never heard of any yew-created
dead zones.  Have you?

Quote:

>c) Does it make any difference if I strain the water before using it ?

If it makes you feel better, certainly, by all means.

I'm not usually this testy, but, I have to say, if this is something you have
time to worry about, you are a lucky man.

--
Pat in Plymouth MI

"Vegetables are like bombs packed tight with all kinds of important
nutrients..."     --Largo Potter, Valkyria  Chronicles

email valid but not regularly monitored

 
 
 

Yew Tree Toxicity Question

Post by Bill » Sat, 19 Mar 2011 01:52:15


In article


Quote:
> Les Hazlewood said:

> >I'm posting this in the hope that someone is able to answer a question
> >about using water that is contaminated with berries and possibly leaves
> >from a Yew tree.

> <snip>

> >Its early in the growing season, and I haven't used any of this water
> >yet, but is it safe to do so, ie:

> >a) Is is safe to eat vegetables that have been watered using this
> >contaminated water ?

> I really can't imagine that they wouldn't be safe to eat.  (Washing them
> with clean water before eating is probably something you already do,
> I assume.)

> Relax! There's far more risk just in travelling to your allotment. Even the
> manure you might use in your garden has more potential to harm you.

> >b) Will the leaves / seeds continue to contaminate the soil, or will the
> >toxins in them break down ?

> Certainly the toxins break down.  I've never heard of any yew-created
> dead zones.  Have you?

> >c) Does it make any difference if I strain the water before using it ?

> If it makes you feel better, certainly, by all means.

> I'm not usually this testy, but, I have to say, if this is something you have
> time to worry about, you are a lucky man.

If it makes you feel any better, Wikipedia says,"Fatal poisoning in
humans is very rare, only occurring after eating a lot of yew foliage.
The major toxin is the alkaloid taxane. The lethal dose is reported to
be between 50 and 100 grams."
<http://en.wikipedia.org/wiki/Taxus_baccata#Toxin>
That is about 2 - 4 ounces.

The taxanes are diterpenes produced by the plants of the genus Taxus
(yews).
<http://en.wikipedia.org/wiki/Taxane>
At the above site you will see that taxanes are rather large molecules
which a plant would have difficulty adsorbing. They are the type of
molecules that plants make from scratch.

The obvious questions to me are does anything grow near the yew tree,
what is the dilution of yew material in grams/liters of water, and how
much water will be used per 100 sq. meters?

I've found nothing to indicate that vegetables will take up the major
toxin found in yew, the alkaloid taxane.

To re-cap, you have dilution, degradation of the toxin in the soil, and
the selectivity of absorption by the plants protecting you.

You owe me a pint ;o)
--
<http://www.youtube.com/watch?v=hYIC0eZYEtI>
<http://www.democracynow.org/blog/2011/3/7/michael_moore>
<http://www.youtube.com/watch?v=eZkDikRLQrw>
<http://www.youtube.com/watch?v=MyE5wjc4XOw>