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
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
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
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
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
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
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
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