On 18/10/02, B. A. Wolfe wrote:
> Just always remember, no matter what anyone tells you: There is no
> such thing as a "safe" poison.

That's because there's no such thing as a safe anything. There is only
safe *use*.

Oxygen is so poisonous that a large fraction of our biochemistry is
needed just to detoxify it, and it barely manages. Lye can either burn
you severely, or make soap to help protect you from disease. Peanuts
can either nourish you or kill you, depending on the way they were
stored. Using an herbicide one time to get rid of a harmful species is
often a safe use. Using the same herbicide several times per year,
year after year, on the same patch of land is often an unsafe use.

It's worth noting that the tires on your car wear to a tarry dust
containing lead, cadmium and other toxins that contaminate soil and
water, poisoning invertebrates and aquatics. Some of the chemicals
that are part of the car life cycle are much more toxic than some
pesticides. But cars are so thoroughly entrenched in the culture that
even many organic gardeners and environmentalists don't think twice
about it--they not only own one, but drive to work every day.

> And any herbicide or pesticide is just that; poison.

If you really think all poisons are the same, then you'll simply flip a
coin if forced to choose whether to swallow a gram of sea salt or a
gram of strychnine :-)

All materials, including pesticides, vary in their effects on different
species, in environmental fate, in manufacturing side effects. There
are some that probably cannot be used safely in such a populous world
(DDT and others that are both broad-spectrum and don't break down
readily or at all). There are other pesticides that when used with
care can absolutely be 'safer' than alternatives, including doing
nothing--I 'risk' using an agricultural insecticide (Frontline, a
prescription use of fipronil) directly on my dog's skin, because it's
the least toxic alternative I could find. If I do nothing, she gets
enormous sores from flea bites; they get infected even when she can't
scratch them. I could make a good case that the antibiotics she needs
for the infections are significantly more harmful to the environment
than the amount of fipronil I use.

> And if it isn't "as toxic" to avian species, maybe
> it is still as toxic to other vertebrate (and invertebrate) species,
> like the fish that will be affected when it gets into the groundwater,
> or insects that are in the area when they spray.

This is an excellent point. It's always worth doing as much homework
as possible about any material that one plans to use, or might come
into contact with. In the case of roundup, the glyphosate (used
properly!) is non-toxic to honeybees, nearly non-toxic to fish, and
only sightly toxic to aquatic invertebrates. The surfactant in roundup
is somewhat toxic to aquatics, so (by law) roundup must not be used
near surface water, though there are glyphosate formulations such as
Rodeo without the surfactant. The Nature Conservancy has used
glyphosate to control spartina in estuaries, leading to a great
improvement of the habitat for all creatures.

> I really hate the
> fact that when people run across something that they can't deal with,
> they have to kill it instead of learning how to live with it

Some of us understand blackberry and other invasive weeds and their
effects on wildlife habitat well enough to know that living with it
means living without a huge variety of insects and birds and other
life. A native plant will have close relationships with 50 or more
other species, from fungi through birds and bees. A non-native plant
enters into less intimate relationships with maybe up to a dozen other
species, more often only two or three. Native plants are also less
likely to grow in monocultures, so a half acre patch of blackberries
partially supporting a dozen species, could, if planted with natives,
contain several interlocking webs of 50+, to support hundreds of
species.

>, or
> trying to find less destructive ways to deal with the 'menace'.

There aren't a lot of good ways to deal with largish areas of it in a
city. In rural areas, you can sometimes burn it, but that effects air
quality and usually takes several burns. You can bulldoze it, but that
destroys the soil structure, making it harder to establish
replacements, and you generally don't want to bulldoze a slope. You
can keep it mown, but it takes two-three years for the roots to give
up, and the mower produces air and noise pollution. There's some
anecdotal evidence that bitter cherry can crowd it out, but it takes
years, and bitter cherry is a weak-wooded tree that could be a hazard
in many urban situations. Goats will eat the shoots if you remove the
mature canes first, but again, it takes several years, and they'd need
supplemental care and protection from abuse.

> yes, I know, Himalayan blackberries can be a real pain in the derriere-I've
> pulled many a plant and dug many a root at restoration sites around
> the city

Great! It's wonderful that you volunteer for weed pulls. Surely it's
given you an idea of why there's so much blackberry still left in
Seattle--too few volunteers, and too much blackberry (and scots broom,
and ivy, and holly, and reed canary grass, and butterfly bush, and ...)
On those pulls, were you completely clearing areas, or were there good
plants intermixed? That can change the trade-offs between hand-pull
vs. herbicide quite a bit.

>, and I have the scars to prove it. At least we didn't kill
> anything but the target species when we did so.

How many people-days did it take to completely control a half-acre section?

> A little sweat equity
> is far less destructive than putting more toxins into the air and
> water we breathe.

I agree in principle, but realistically, how much of that sweat equity
is available compared to the amount of weedy areas that need to be
reclaimed? Are you willing to call Children's and volunteer to do it
by hand for them? If you personally can't make that offer, who do you
expect to do it? Who's going to donate the money to hire someone to do
it by hand? Roundup will cost about $200 plus about one man-day. Is
there any manual technique that can come even within an order of
magnitude of that? If so, I'd love to know about it, because this
topic comes up quite a lot on various groups, and it would be fantastic
to have an excellent--and realistic--alternative to suggest.
--
Allyn Weaks allyn at tardigrade.net Seattle, WA Sunset zone 5
Pacific NW Native Wildlife Gardening: http://www.tardigrade.org/natives/
"The benefit of even limited monopolies is too doubtful, to be opposed
to that of their general suppression." Thomas Jefferson