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Dealing with onion weed

 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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We have onion weed all over our garden (Nothoscordum gracile). It has thin strappy leaves, and a small white bulb. The bulb grows new little bulbs which break off (particularly when you try to get it out) to form new weeds. It also has flowers and can spread by wind.

Most of what I've read is saying pretty much the same thing, you either have to carefully physically remove it, or spray with something like Roundup (glyphosate).

Removing from bed is okay, but tedious. As long as it is removed at a young enough age (i.e. very small bulb) and carefully you can get it out of the ground. As soon as it is old enough to start forming bulbs, it is a real pain, but you can get rid of it by taking it out carefully with the soil around it so that the new bulbs are removed too.

Spraying with Roundup has had mixed results. I would say that it appears to kill it after a second spray...still not too sure though. I've seen recommendations of dripping motor oil into the crown, but I haven't tried that.

It is frustrating, but manageable when growing in beds, but the problem that I have is that there are places in my grass where it is going. Spraying with Roundup is not really an option, and digging it out requires major damage to the grass. The main problem is that the weed grows up through the grass. I would guess the bulb is about 4 inches deep, and it is very difficult to actually get the bulb out (the stem breaks off very easily). If the bulb remains, it just grows back.

I put new grass in last year (there was nothing but weeds when we moved into this house), and I've been following the cheap and lazy lawn care principles since I found them. We're about to go into spring here (Southern hemisphere), and I'll be adding a layer of topsoil to supplement and smooth out the lawn.

I'm a bit wary of just leaving them to grow and hoping that it will sort it self out. I'm making sure that they stay trimmed to ensure they don't seed. At the moment it looks like my options are to leave it and hope for the best, or lift sods of grass and try to removed manually. Main problem is that there is no way of ensuring it is all out, and the tiny bulbs can easily be left in the ground.

I was wondering if any one had some suggestions? Maybe our soil needs some adjusting to help? Or must I just keep working on the cheap and lazy principles, and in a couple of years it will be better?

Thanks
 
paul wheaton
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Can you eat them?

I've never encountered this sort of thing. 

How do they respond to mowing?  I would think that onions would really hate mowing.

In the garden, I would put hay over them - push over the tops and lay hay on them.  The hay will smother them and introduce rot.

 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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I don't think you can eat this stuff. It actually doesn't smell like onion at all. It grows relatively flat, and has a thin strap like stem (unlike a spring onion that grows more upright and has a thick onion smelling stem).

I think the particular weed I have is sometimes called False Onion Weed. There is another type I found on the net, Asphodelus fistulosus which I think smells a bit like onion when squashed.

There is no top to push over really. Won't the hay cause problems with the grass too?
 
paul wheaton
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In the garden, I like to smother stuff with hay. 

In the lawn, I can't smother stuff with hay because I would then smother the grass too.

In the lawn, most weeds give up when you get a tall, thick, healthy turf that is watered infrequently.

Can you post a pic?
 
                                  
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Location: Chicagoland area
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I also have what appears to be green onions growing in/around my lawn.  I think the prior owner must have been growing them for food usage.  They are prolific and annoying!!!

They start off looking like softer, lighter grass... then within a week they are 20% taller than the turf/grass and they smell like sweet onions when you mow.  The only solution has been to get down and dig up those bulbs.  Even if you pull out the stalk from 4-6" deep, that bulb will grow another one in a week or so.

If you let them grow for 2-3 weeks, they will really look like green onions you buy at the market.  I have not tried to cook w/ them.  Good luck..
 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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snufflet wrote:
I also have what appears to be green onions growing in/around my lawn.


These don't actually smell of onion when they are cut, or the bulb is squashed, and their appearance is quite different to the spring onion I have growing in my herb garden.
 
paul wheaton
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duncan drennan
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Location: Cape Town, South Africa
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I just realised the links in my first post were broken. I've fixed them now, and there are pictures of the weed there. Just in case, here are the links again,

Pictures of weed and bulb: http://www.sydneyweeds.org.au/weeds/onion-weed.php
Pictures of flowers: http://www.yates.com.au/ProblemSolver/OnionWeed.asp
Ideas for killing: http://www.au.gardenweb.com/forums/load/ozgard/msg1010091812133.html

I'll see if I can grab a big one from the garden where you can see the small bulbs that it grows around the main bulb.

I've been wondering whether they possibly prefer an acid or alkaline soil, but I'm not too sure where I can find out about that. I could try experimenting with the ones in the open beds — it would just take a while.
 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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Okay, here are some pics from my garden. This is the onion weed in the ground. You can see the blades lie fairly flat on the ground. This particular clump had its bulb about 2 inches under the ground.
onion_weed_digging_up_small.JPG
[Thumbnail for onion_weed_digging_up_small.JPG]
onion_weed_in_ground_small.JPG
[Thumbnail for onion_weed_in_ground_small.JPG]
 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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The younger bulbs do not have any of the small "seed bulbs" growing on them, but once they get a little bigger, the small bulbs form. When you take them out of the ground you have to be careful to ensure that the whole bulb comes out without either breaking, or dropping of a gazillion little new bulbs.

The "seed bulbs" are the small brownish things you can see amongst the soil. Sometimes when the weed is younger they are still white like the bulb, and don't drop off as easily.
onion_weed_bulb_seeds.JPG
[Thumbnail for onion_weed_bulb_seeds.JPG]
young_onion_weed_small.JPG
[Thumbnail for young_onion_weed_small.JPG]
 
paul wheaton
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Do you have pics of this stuff growing in your yard?

For the garden, I would throw hay on top of it.  This would smother the weeds and feed the plants.  Just pick up a couple of bales of hay at farm supply store.    This is also going to work long term at keeping them from coming back. 

As for in the grass:  is it just the look of it that bothers you?  How does it feel under bare feet?  I'm guessing that in the lawn, it isn't laying down.

The flowers look nice.  Do they flower in your yard? 

Do the one that have been mowed look like they like mowing? 



 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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I just mowed the lawn yesterday, so you can't really see it. I'll take a pic when it starts to grow again. It grows up above the lawn, and you don't feel it underfoot. The main thing I'm worried about is it getting out of control if it is just let to its own devices. It might even be that with a season of strong growth for the lawn, that it won't really come back next year.

It is a pretty flower, but it has to get quite big before it flowers. If I remember correctly they will start flowering late in spring (I'm in the southern hemisphere, so we're about to go into spring). I'm doing my best to make sure that they don't flower and spread further.

Mowing doesn't really seem to bother them at all, it just keeps on growing. The blades of the mower don't really seem to pick it up well and cut it, as it just gets pushed over.
 
paul wheaton
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Try mowing a little more often. 

What would your lawn be like if this stuff filled out 90% of your lawn?  Would it feel funny underfoot?

I guess I'm trying to fish around and understand why you want this stuff to go away.

I understand wanting to get rid of thistles.  Ouch!

I understand wanting to get rid of a mature dandelion.  Not as nice to walk on, and the lawn doesn't look as nice.

I understand wanting to get rid of bindweed.  It'll take over all the non-lawn growies.

Just trying to get a grip on this one.  Maybe a pic of it in the lawn and I'll understand.





 
duncan drennan
Posts: 18
Location: Cape Town, South Africa
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Okay, I finally am posting a picture...

Paul, I hear your point. The weed is not hard underfoot. The leaves are a bit waxy though. It does, in my opinion, look pretty ugly in the lawn, although you don't really notice it when it is mowed. Problem with that is that it is difficult to mow (many passes with the reel mower to actually get it - it kinda pushes over in front of the mower).

The big thing I'm worried about is having this stuff slowly spread through the whole lawn. It is definitely classified as a weed, but it is not on the alien invader list, so I couldn't use that as an excuse either   It is just generally considered a real pain, as it is difficult to get rid of. It is not indigenous (it is from North America, I'm in South Africa - my gran says it was originally brought in by florists).

Anyway, that is my story. I still want to get rid of it - its propagation method bothers me quite a bit...
onionweed_in_grass.jpg
[Thumbnail for onionweed_in_grass.jpg]
 
paul wheaton
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I remember reading a book called "cool hand luke".  In that book, they talk about a "yo yo" for cutting grass.  You swing it back and forth and it cuts weeds.

Sometimes if I wait too long between mowings, I get this out and cut the tall stuff first - so that the reel mower can cut it to the proper height.

In the pic, is the onion weed the stuff that is a ways back? 

 
duncan drennan
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Location: Cape Town, South Africa
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I remember the movie "cool hand luke" - but all I can remember is an egg eating competition. But that is a whole other story.

Anyway, the onion weed is the stuff in the foreground with the slightly broader leaf and the brownish tips (due to the mowing). It doesn't look much different to the grass in that photo. The grass has a much narrower leaf and it is not so long. There is one in the background too popping out quite high above the grass. The orange in the far background are marigolds.
 
paul wheaton
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I'm gonna break this in two:  1) what I would do, and 2) my advice for you to do what you want to do.

1) I would leave it.  It looks fine to me.  In fact, I would plant a variety of other stuff in there too, yarrow, chamomile, crocuses, etc.  All sorts of fun lawn growies.  And then the onion weed doesn't look out of place and the lawn looks really diverse!  Flowers and all sorts of plants that are soft underfoot, but have all sorts of interesting textures.

2) You want to have a monoculture.  This runs against nature, but sometimes you can pull it off without chemicals.  I used to do a lot of hiking in the wilderness and I would live off the land a little as I went.  I did eat a few wild onions.  I found them in swampy areas.  I wonder if you could train your grass to send down deeper roots and then water less often.  I would guess that the onion grass has shallow roots and will not care for this.
 
duncan drennan
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Location: Cape Town, South Africa
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Maybe (1) is the way to go. I am gradually reducing my lawn area and planting indigenous plants (we have beautiful indigenous plants here in the Western Cape of SA - see PlantzAfrica, and Cape Flora. I'll think a bit about what my options are in that regard.

With regards to (2)...hmmm....this is THE problem with the onion weed. I've seen some of this stuff with roots 4 inches into the ground. The grass roots are getting deeper, and I keep encouraging them deeper. It is no problem in the summer (the onion weed seems to actively grow through the rainy winter).

At this point I'm just going to manage it (i.e. mow regularly, water deep and seldom) and see whether it gets better or worse, and continue to reduce the grass area and plant shrubs.

Thanks for all the input
 
                  
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Hi Guys  by the photo you do not have onion weed but a weed called nut grass which is also very hard to get rid of.
The grass photos are harder to work out but may be a bulb or a weed .
Google -onion weed and look for the Noxious weeds of Australia link-Google books for photos
scientific name Asphodelus fistulosus L.
Onion weed is Cyperus rotundus
Good luck
 
Chris Rowland
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Duncan, can you give any advice to me now that some years have passed? I have the same problem with onion weeds propagating in a sandy area of my garden and now spreading into the lawn...

Many thanks,
Chris
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