Moss and Liverwort killer

Mary Sue Ittner
Sat, 31 Jan 2004 10:02:13 PST
Dear Diana,

I remembered that Will Ashburner had a system for killing these he posted a 
number of years ago so I looked for it in my archives and found it. (from 
October 1997). I haven't heard from Will in awhile, but I am sure he'd be 
be willing to let me share what he wrote in two messages about what to do. 
I have also seen listed in various catalogs of companies that sell products 
that are supposedly more environmental friendly sprays. So if you are 
interested in those resources too let me know. I don't think Will ever 
wrote a follow-up, year down the road post on this. Let us know if it works 
for you.

Mary Sue
"Dear all,

Last year Fausto asked if the Robin had any ideas how to control Moss and
Liverwort on the tops of Pots.

I made a few suggestions one of which was Vinegar which I hadn't tried on
bulbs.  Well I have now.  Vinegar works I think because it lowers the ph of
the media which mosses and liverworts don't like.  The dilution is 1 to 4
of the cheapest vinegar you can find.

Well the results.  I had a little problem with mainly mosses growing on the
punnets of first year seedlings.  It happened because I decided to change
my technique, normally I would cover the seedlings with coarse sand (grit)
which inhibits the growth.  This year at sowing time I didn't have any
available till later and have since found how useful the sand is as an
inhibitor.  I decided to do a test with the vinegar and found it did a
marvellous job of killing the moss.  It should be applied on a sunny day,
for some reason it is not as affective in shady spots.

I didn't do all my seedlings but have found that some weren't too happy.
  The Alstroemeria were burnt off, they have since recovered and some
others seem to have gone into dormancy prematurely.  It is hard to know if
they were going dormant any way.  The only link with the others that seemed
to be adversely affected was that they were hairy leaved South Africans.

If the group would like more information I could check the labels and list
them in another posting.

Dear Joyce and all,

During my couple of days of last week I spent a bit of time with my bulbs
and assessed the effects of the Vinegar drench I imposed on the 1 year old

I mentioned that I thought it had caused some hairy South Africans to go
into early dormancy,  I am not so sure now and think it was natural.

The rest of the pots were also treated with vinegar, this time I filled up
a small 1/2 litre hand sprayer and just sprayed the tops of the pots on the
morning of a sunny day.  By the next day the mosses and liverworts were
going brown.  This technique means that you can miss a few patches but
unlike drenching you only need a small amount of the 25% vinegar mix.

The only genera that has adversely effected has been Alstroemeria.  This
year I have an extraordinary wide range of bulbous species from Albuca to
Xerophyta and all in between, I haven't treated any South African
amaryllids in this way.

I have done some treatments to pots in the shade but haven't assessed them

All the best

Will Ashburner"

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