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Best strategy to control Shotweed (Cardamine hirsuta)?

Posted by wynswrld98 z7 WA (My Page) on
Fri, Apr 12, 13 at 23:08

So Shotweed is my #1 nuisance weed I'm trying to control/eradicate. For those of who are winning the battle with it can you recommend what you found to be the best strategy?

What I'm currently doing is putting a thick layer of Cedar Grove Compost in the planters that are prone to have it hoping I smother out seeds never to see them again (will this work?). I obviously try to pull and dispose of plants I see before they get to flower/seed.

I'm also curious what anyone knows about how long the seeds are viable, if given water do they all leaf out at once? or only some at a time and others leaf out later?

Ref: https://www.google.com/search?q=shotweed&tbm=isch&tbo=u&source=univ&sa=X&ei=xstoUfyfL4GsiAKEioDgBQ&ved=0CDAQsAQ&biw=1904&bih=844#imgrc=2QD7mQQnXXx6wM%3A%3Bx-vGoLiVHD6k4M%3Bhttp%253A%252F%252Fupload.wikimedia.org%252Fwikipedia%252Fcommons%252Fd%252Fda%252FKleine_veldkers_Cardamine_hirsuta_plant.jpg%3Bhttp%253A%252F%252Fprism.xomba.com%252Fedible_weeds_garden_kitchen%3B1278%3B1704

I've fought a battle with Herb Robert for many years and rarely see them anymore, am hoping I can do the same with Shotweed. I'm also starting a battle with Creeping Jenny in the lawn in about 6 small patches, trying to eradicate it before it spreads.


Follow-Up Postings:

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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

Remove before they set seed. Then continue to patrol the area for "leftovers" or later sprouter-bloomers.

I doubt any weed sprouts all its seeds at once." That's a very poor strategy when you intend to conquer" an area.


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sat, Apr 13, 13 at 12:37

Use a coarser mulch and keep it topped off.


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

A coarser mulch such as what? I've been putting the Cedar Grove Compost about 3" thick on the planters figuring it would smother the seeds (can't imagine they'd germinate if they're buried that deep but perhaps they still do??) and also improve the soil in the planters.


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sat, Apr 13, 13 at 23:20

Bark, wood chips etc. Fine composty surfaces excellent for germination of shotweed and others. Also less effective at moisture retention, you want a markedly different texture from the soil beneath in order to keep moisture in.


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

Don't bark and wood chips rob the soil of nitrogen as the bark/chips decompose?


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

Not if they remain on the soil surface.


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

  • Posted by corrine1 7b Pacific Northwest (My Page) on
    Sun, Apr 14, 13 at 10:55

Anytime you pierce through that mulch layer & bring up soil from below the weed seeds will resurface & sprout.

Containers are different than in ground gardens, so I've not tried a wood chip mulch in them.

You might try removing the top few inches before you add transplants then fill your containers to within 1 inch with new potting mix. If planting seeds in containers you definitely want new potting soil mix.

Control weeds in the ground around the pots. If containers are planted densely & mulched with a thin layer of dried grass clippings to cover the soil surface you may have a weed free container quickly.

Like other posters have said do patrols & remove the sprouts. It regenerates from pieces, so definitely don't use a tool to chop it up.

Corrine


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

Re: nitrogen and bark doesn't the soil start to decompose the bark as soon as you put it down? I don't understand how it's possible to "keep it on the surface".


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RE: Best strategy to control Shotweed (Cardamine hirsuta)?

It will remain on the surface as long as you don't dig it into the soil.

If you plant something new after the area is mulched, you need to pull back the mulch, plant, then replace the mulch on the soil surface.


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