Rain, Rain & more rain

Harold,
I’d love to send you back some of our rain – it mostly seems to come from the West!

These pictures show another reason why I’d like a lot less rain. We missed summer and have had so much rain that mosses various are everywhere this year – our driveway is green and the place looks derelict!

This little plant (Liverwort I think?) just about covers the outside raised bed in which I sowed my 2010 seeds. When trying to physically to remove it about an inch or more of soil and grit comes with it – and perhaps seeds that may not have germinated. I fear if I do not get it destroyrd that the little seedlings will not be able to compete or penetrate this plate like green cover.

I’m looking for a spray that will kill it and not damage the emerging seedlings!

Armillatox has been suggested? What about Formalin or chlorine? At what strengths? I’ve done a little trial patch with the cocktail solution used in the Hot Water Tank.

Any suggestions – or good ideas???
Brian

7 comments for “Rain, Rain & more rain

  1. Brian:

    Household bleach might work but you will have to experiment with the dilution. That is a liverwort.

    All sorts of daffs starting to flower for us and I actually harvested the first pod last week. N. elegans x N. cavanillesii. Should be quite ugly :-)

    Harold

  2. Harold,
    You think up the most amazing crosses – not many of us breed for ‘UGLY’ – may your ‘ugly daffodil’ be as famous as the ‘ugly duckling’. I can’t see it wanting to live amongst the Liverwort here in N. Ireland.

    I’m a bit frightened of Bleach – I tend to make things too strong to be sure to be sure – and that might kill what I want to keep alive!
    Brian

  3. Hi Brian,

    I have used vinegar as a spray for Liverwort and it works, so maybe it is worth a try for you.

    Cheers
    Malcolm

  4. Malcolm,
    I like the idea. Thanks. Vinegar is acid – so I assume it may lower the pH and I have also assumed, perhaps wrongly, that Liverwort likes a low pH.  If so then maybe limestone is a possible addition?

    We tend to think we know so much  – this sort of experience is salutary!

    Brian

  5. Ah Marchantia,  I think that is how it is spelled.  Vinegar is some times used.  I beg it to put in garden but not on my seed pots.

    Nancy

  6. Thanks Nancy,
    The generic name Marchantia has led me to Google where I find its specific name is polymorpha which I take to mean it has many forms. So much information available! It is a plant undergoing so much research but all to deep to answer my simple question about preferable pH – or at least my short search did not reveal the answer if there is one – maybe it just grows in the wet!
    Brian

  7. from below:
    “Acetic acid (5%) provided excellent liverwort control, and can be
    used as long as you use
    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/../acetic_acid_factsheet.pdfproducts
    containing vinegar that are legally labeled for weed control..”
    m

    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/liverwort_control.html

    Marchantia polymorpha may be the most troublesome weed problem in
    containers (in Oregon).

    Before talking about how to kill liverworts, let’s talk about
    conditions in which liverworts thrive. Liverworts grow vigorously in
    conditions with high humidity, high nutrient levels (especially
    nitrogen and phosphorus), and high soil moisture. In an environment
    that has any of these 3 conditions, it will be difficult to control
    liverworts (even when using herbicides). In order to effectively
    control this weed, you must make growing conditions for the
    liverworts as difficult as possible. To do this, you should attempt
    to create an environment where the ambient air is dry, the surface of
    the container is dry (as dry as possible), and nutrients are not
    available on the container surface.

    Preemergence Control

    Preemergence is the best way to control liverwort, however, liverwort
    cannot be controlled with herbicides alone. For effective control,
    you must use cultural practices that deprive liverworts of the moist,
    high fertility, and humid conditions it thrives in. And for added
    control, a preemergence herbicide along with modification of your
    cultural practices will help considerably.
    * Topdressing fertilizers is the number one way to INCREASE
    liverwort growth and accelerate its spread through your container
    yard. By incorporating fertilizers (into your media), you remove most
    of the nutrients from the container surface (though not all
    nutrients) and thus make it more difficult for liverworts to grow.
    Dibbling fertilizers will further reduce liverwort populations.
    Dibbling involves placing the entire amount of fertilizer for each
    container beneath the rootball of the liner while potting up. Many
    fertilizer manufacturers recommend against this practice due to
    concerns over liability. Some crops are sensitive to dibbling
    fertilizers because of high salt levels being so close to the plant’s
    rootball. However, in our research, and the work of many other
    scientists, indicates that many species of plants grow well when
    fertilizers are dibbled. In fact, dibbling fertilizers generally
    results in superior plants compared to incorporating fertilizers, and
    similar sized plants compared to topdressing. Many nurseries use this
    method routinely. Before dibbling fertilizers with your plants,
    conduct small trials to see if it works with your cropping system.
    Also, only use products that are rated to deliver nutrients for 8 to
    9 months or longer. Controlled release fertilizers that release their
    nutrients in 3 to 4 months are more likely to injure your crops when
    dibbling. And it is generally better to dibble fertilizers in the
    spring, and not in late fall (due to potential build-up of salts
    during extremely cold conditions of winter).
    * Consider ways to modify your irrigation practices to limit
    overwatering. Many growers overwater their container crops. Water is
    abundant, and generally overwatering will not injure crops (except in
    some cases where overwatering causes root disease). So it is ‘safer’
    for growers to overwater rather than risk under-watering. However,
    liverworts (and pearlwort) thrive in wet conditions, and any practice
    that limits the amount of water will decrease liverwort vigor.
    *
    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/weeds_and_water.html
    water affects liverwort growth
    Changing your media to a mix that has better drainage will also
    reduce liverwort vigor. Coarse media that drains well, especially
    near the surface, is ideal. Coarse bark, pumice, perlite, and
    vermiculite would work well to increase drainage. Peatmoss, choir,
    compost, sawdust, and fine bark will increase a media’s water holding
    capacity and thus increase liverwort vigor. For optimum liverwort
    control and optimum crop growth, try to develop a mix that is coarse
    enough so that it dries on the surface rapidly, but fine enough to
    retain and provide adequate water to crop roots below the surface of
    the container.
    * Another way to decrease liverwort vigor is to increase air flow
    throughout your crop (and thus decrease humidity near the container
    surface). Can you lift the sidewalls of your hoophouse, or raise the
    sidewalls of your Cravo? Can you arrange your plants with wider
    spacing or in straighter rows to increase air circulation between
    plants and around the container surface? Anything that increases
    airflow and decreases humidity should help reduce liverwort vigor.

    Postemergence Control

    There are no herbicides labeled for postemergence liverwort control
    in containers. Sven Svenson did a great deal of work on postemergence
    control, however, the products he found to be successful were
    generally also phytotoxic to nursery crops as well, or not labeled
    for nursery crops (and thus not legal). So, it does no good for me to
    list products that are illegal to use anyhow. But here are a few
    points to consider:
    * My experience is that Roundup provides poor liverwort control
    (which of course can only be used on nursery floors, and not in containers).
    * Acetic acid (5%) provided excellent liverwort control, and can
    be used as long as you use
    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/../acetic_acid_factsheet.pdfproducts
    containing vinegar that are legally labeled for weed control..
    * In general, products used for postemergence liverwort control
    will work better if sprayed before
    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/sporocarp_page.htmlsporocarp
    formation (personal communication with Sven).

    ———-
    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/../../research/container_trials/trial_2003.htm2003
    preemergence herbicide trial for liverwort control

    http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/../../research/mogeton/main_page.htm2003
    postemergence herbicide trials for liverwort control

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