In article ,
wrote:

On Mon, 05 Apr 2010 17:57:36 -0700, "David E. Ross"
wrote:

On 4/5/10 1:23 AM, Stewart Robert Hinsley wrote:
In message
,
Billy writes
In article ,
"David E. Ross" wrote:

On 4/4/10 7:47 PM, MiamiCuse wrote:
South Florida zone 10b.

I have planted some Costus (Ginger family) in a 50' long planter area.
However the weeds are growing like wild fire and I am unable to keep up
with
pulling them. I wanted to use some weed killer to control the weeds
(clover
leaf type, see a pic here
http://www.biology-blog.com/images/b...-leaf-3100.jpg
),
but
have heard that weed killer will also kill plants that have rhizones
which
my Costus is.

Is this true? Is there a better way to control the weeds beside hand
pulling?

Thanks,

MC



Take a piece of the weed -- not merely one leaf -- to a "real" nursery
(not a lumber yard or hardware store) for identification. This might be
oxalis instead of clover.

The photo looks like oxalis.

There is a specific weed control that severely burns oxalis,
sufficiently to kill most of it, without harming other plants (except
for spotted spurge, another weed). Sold under various brand names, it
contains ammonium thiocyanate, which quickly decomposes into a urea form
of fertilizer; sodium thiocyanate is about as effective. Any oxalis
plants that survive must be hand dug, for which I recommend the use of a
paring knife. Be alert! Oxalis readily forms seeds, which are not
affected by the chemical; the thiocyanates act only on growing foliage.

If your weed is indeed clover, hand pulling is the best control. Do
this before it flowers, and you won't have to repeat. Try to leave some
of the roots in the soil; they are an excellent source of nitrates for
nurishing other plants.

Sorry David, but it looks like bullshit to me, thiocyanate is sulfur +
cyanide. Pull the god damn weeds. Don't be a lazy ****. You don't want
to eat heavy metals. Oxalis isn't that invasive, and kids love to chew
it, even if it does bind up calcium.

I don't find Ammonium thiocyanate as a narrow-spectrum weedkiller
particularly plausible, but there are no heavy metals involved.

Google's not being particularly informative today, but it looks as if
ammonium thiocyanate is usually used combined with aminotriazole
(amitrole) - and acts by slowing the action of the aminotriazole
allowing it to reach the roots and kill the whole plant, rather than
just the leaves.

This combination is marketed as an oxalis killer
(http://www.agspray.net.au/msds/oxalis.pdf), but it is also recommended
for the control of "grasses, broad-leaved weeds ... & nut-grasses".
Given that range I expect that it will kill Costus quite happily.

Aminotriazole, fide Wikipedia, is a carcinogen.

There are products marketed for the control of broad-leaved weeds in
pastures and cereal groups. But while Costus is a monocot, sensitivity
to weed killers doesn't line up nicely with phylogenetic clades (e.g.,
fide Wikipedia, bromoxynil is used with flax and mint, as well as with
monocot crops), so it cannot be assumed that Costus is not sensitive.
Broad-leaved weed killers tend to be nastier chemicals.

The last time I looked at a bottle of Oxalis-X, the only active
ingredient was ammonium thiocyanate. No amitrole, no other herbicide.

Ammonium thiocyanate will burn other plants; but in most cases it will
not burn sufficiently to kill the plant. However, the label did warn
against spraying it on or near junipers. It is effective against
growing oxalis and spotted spurge and leaves no residue other than urea
(a fertilizer) and sulfur (good in my alkaline soil).

I haven't bought Oxalis-X in a long time. Fortunately, oxalis is now a
rare weed in my garden. When I find it, my paring knife digs it out
(with help from my right hand).

Unfortunately, spotted spurge is too common in my garden. But it tends
to grow my decomposed granite walkways where I can use Roundup.

One precaution in keeping oxalis out of your garden is to inspect
carefully all containers of new plants at the nursery. Oxalis is often
found growing in the containers that also contain the shrub or perennial
you really want to buy. Buy only the desired plant, and reject any that
come with oxalis.

i'm confused. I googled oxalis and clicked on
http://en.wikipedia.org/wiki/Oxalis

Is this regular wood sorrel that is trying to be eradicated? (I admit
I really like wood sorrel and welcome it.)

I water them, and the ferns until mid-summer, when they disappear with
no help from me. I can see purplish-pink ones out my study window right
now. For the time being I have the white flowers of wild onions, the
oxalis, blue forget-me-nots, and pink dead nettles for color in my yard.
It's not that bad.
--
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.

http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html

"Una" wrote in message ...
Billy wrote:
Sorry David, but it looks like bullshit to me, thiocyanate is sulfur +
cyanide. Pull the god damn weeds. Don't be a lazy ****. You don't want
to eat heavy metals.

What heavy metals?

In any event, I would simply pull the weeds. Do it in spring and you'll
be done with them. I'd rather spend a few hours pulling weeds than many
more hours researching, shopping for, and applying herbicides.

Una


I am confused. You all suggested to pull the weeds. I have spent 3-4 hours
on my knees pulling the weeds. Two weeks and one rain storm later they are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

So this year, I dug up ALL the costus, all their roots along the entire
planter area. I then turned the soil over several time, pull out all the
weeds and their roots. I then laid down weed barriers, except for a sliver
down the middle. Planted the costus back in, then put 3" of granite over
the entire area.

So far so good.

Then we had some heavy rain. Then they are ALL BACK, again, through the
weed barriers, through the granite.

"Phisherman" wrote in message
...
On Sun, 4 Apr 2010 22:47:28 -0400, "MiamiCuse"
wrote:

South Florida zone 10b.

I have planted some Costus (Ginger family) in a 50' long planter area.
However the weeds are growing like wild fire and I am unable to keep up
with
pulling them. I wanted to use some weed killer to control the weeds
(clover
leaf type, see a pic here
http://www.biology-blog.com/images/b...-leaf-3100.jpg ),
but
have heard that weed killer will also kill plants that have rhizones which
my Costus is.

Is this true? Is there a better way to control the weeds beside hand
pulling?

Thanks,

MC



Flowerbeds should either be small (to reduce hand weeding) and/or
mulched to control weeds.

It is small in a sense that it is only three feet side, but 50 feet long
(along the perimeter of the house). I had weed barriers down, on top of it
is 3" of granite stones.

Didn't matter, they spread like wild fire. I pulled them, they come back in
two weeks.

MC

MiamiCuse wrote:
I am confused. You all suggested to pull the weeds. I have spent 3-4 hours
on my knees pulling the weeds. Two weeks and one rain storm later they are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

I think we need to see a photo of the actual weeds in your Costus bed.

Also, do you literally "pull" the weeds?

Una

In article ,
"MiamiCuse" wrote:

"Una" wrote in message ...
Billy wrote:
Sorry David, but it looks like bullshit to me, thiocyanate is sulfur +
cyanide. Pull the god damn weeds. Don't be a lazy ****. You don't want
to eat heavy metals.

What heavy metals?

In any event, I would simply pull the weeds. Do it in spring and you'll
be done with them. I'd rather spend a few hours pulling weeds than many
more hours researching, shopping for, and applying herbicides.

Una


I am confused. You all suggested to pull the weeds. I have spent 3-4 hours
on my knees pulling the weeds. Two weeks and one rain storm later they are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

So this year, I dug up ALL the costus, all their roots along the entire
planter area. I then turned the soil over several time, pull out all the
weeds and their roots. I then laid down weed barriers, except for a sliver
down the middle. Planted the costus back in, then put 3" of granite over
the entire area.

So far so good.

Then we had some heavy rain. Then they are ALL BACK, again, through the
weed barriers, through the granite.

Please, give us a picture. You have been asked many times. Your plant
doesn't sound like oxalis.
--
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.

http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html

On 4/7/10 4:41 PM, MiamiCuse wrote:
"Una" wrote in message ...
Billy wrote:
Sorry David, but it looks like bullshit to me, thiocyanate is sulfur +
cyanide. Pull the god damn weeds. Don't be a lazy ****. You don't want
to eat heavy metals.

What heavy metals?

In any event, I would simply pull the weeds. Do it in spring and you'll
be done with them. I'd rather spend a few hours pulling weeds than many
more hours researching, shopping for, and applying herbicides.

Una


I am confused. You all suggested to pull the weeds. I have spent 3-4 hours
on my knees pulling the weeds. Two weeks and one rain storm later they are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

So this year, I dug up ALL the costus, all their roots along the entire
planter area. I then turned the soil over several time, pull out all the
weeds and their roots. I then laid down weed barriers, except for a sliver
down the middle. Planted the costus back in, then put 3" of granite over
the entire area.

So far so good.

Then we had some heavy rain. Then they are ALL BACK, again, through the
weed barriers, through the granite.



If it is oxalis, new plants will arise from pieces of stem. When you
pull them, they will regrow unless you also remove the root. And the
plant is perennial; if it appears to have died, it is only dormant.

If you let it bloom, the tiny seed pods (about 1/2 inch long) will
release their seeds explosively, scattering their seeds widely. Walking
across an infested lawn while wearing shorts, the seeds feel like gnats
keep flying onto my legs. The seeds are slightly sticky and are thus
easily spread by humans and other animals walking over a patch of oxalis.

As I indicated earlier, I use a paring knife to ensure that I get some
of the roots. I attack oxalis before it can bloom. If I see it, I stop
whatever else I'm doing and remove it. Fortunately, prior use of
ammonium thiocyanate (YES!) eliminated the worst of the infestation.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening diary at http://www.rossde.com/garden/diary

Someone said:

I am confused. You all suggested to pull the weeds. I have spent 3-4 hours
on my knees pulling the weeds. Two weeks and one rain storm later they are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

So this year, I dug up ALL the costus, all their roots along the entire
planter area. I then turned the soil over several time, pull out all the
weeds and their roots. I then laid down weed barriers, except for a sliver
down the middle. Planted the costus back in, then put 3" of granite over
the entire area.

So far so good.

Then we had some heavy rain. Then they are ALL BACK, again, through the
weed barriers, through the granite.

You obviously got lousy advice... who's the imbecil who told you to
place stone chips over cloth weed barrier?!?!? DUH Stone chips go
over heavy polyethelene sheeting that won't decay fro many, many
years... used where you never want anything to grow, in lieu of
concrete... the stone chips (hopefully decorative) are for hiding the
ugly poly and to keep it from blowing away. Your weed barrier cloth
didn't work for one reason and one reason only, you used the crappy el
cheapo kind. Buy premium weed barrier cloth, even use it double in
problem areas, like slopes... then cover with shredded bark, wood
chips, or any other organics that will slowly decompose, adding fresh
as needed. Stone chips do absolutely nothing to improve soil, and
even if laid down a foot thick weeds will grow, because some weeds can
push through from below and some seeds will fall on the chips and will
root through... plus bits of organic matter and clumps of soil will
constantly sift through creating a very nice substrate for all manner
of native plants to propogate... I suggest you get rid of all those
stone chips before you find them strewn all over your property... save
them for when you plan to mix up a batch of concrete, or add to a
crushed stone driveway.

"Una" wrote in message ...
MiamiCuse wrote:
I am confused. You all suggested to pull the weeds. I have spent 3-4
hours
on my knees pulling the weeds. Two weeks and one rain storm later they
are
all back, in full force. The weeding has to be done every two to three
weeks, continuously from March to November. That's what I have been doing
last year.

I think we need to see a photo of the actual weeds in your Costus bed.

Also, do you literally "pull" the weeds?

Una


Yes I try to pull the weeds, sometimes I was able to get the roots out,
sometimes the stems broke.

Here are some pictures. The first picture are the Costus with the weeds
underneath, and the second one is of the weeds.

http://i173.photobucket.com/albums/w...b/P1000002.jpg

http://i173.photobucket.com/albums/w...b/P1000003.jpg

Thanks,

MC

Now we're getting somewhere. That looks like Oxalis. Try chewing one. If
sour, probably it is an Oxalis. Trifolium (clover) has a flavor that reminds
me of grass. In mid-day full sun do the leaves droop (not wilt!), as in this
photo?: http://en.wikipedia.org/wiki/File:Ox...la_flowers.jpg
Can you find any in flower (look in lawn adjacent to your Costus bed)? The
flowers of Oxalis and Trifolium are easy to tell apart.

Here's a pamphlet about Oxalis in Florida:
http://edis.ifas.ufl.edu/pdffiles/FW/FW02900.pdf

These are distributed like seedlings, so from seeds falling there after you
laid the gravel. Source is likely your lawn or your neighbor's lawn. Explore
a bit in the crushed stone to see if the roots are little bitty seedling
roots or what. Some Oxalis produce bulbils on their roots and when you pull
out the root you are likely to leave the bulbils behind. The bulbils sprout
new plants.

Here's what I do with seedling crops. I first wait for most of them to die.
That is the fate of most seedlings. Or I would lightly rake the rocks with
a gardening claw, taking care not to damage the Costus. Any seedlings that
survive I would dig out using a gardening tool to ensure I get enough of the
root that it does not come back.

To prevent future seedling crops, find and eradicate the source. If this is
Oxalis, you can treat with the specific herbicide others have mentioned. But
if you don't eradicate the source, it will return.

Are the Costus growing on top of the fabric, or did you puncture it for each
plant?

You have a "stone mulch" there. If you decide you don't like it after all,
now is the time to take it all out and replace it with an organic mulch. I
like organic mulches in part because it is easy to add more right on top of
a seedling crop like this and kill the seedlings. However, if cats messing
in the flowerbed are a concern, the stone mulch should discourage them.

Hope this helps,

Una