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Re: Favourite Thug for a Med. Garden

> >Ok, I'll bite! My favorite Garden Thug is also a geranium. I know it only as
> >geranium robertianum (herb robert). 

Hi David 
 You wrote> 
> Goodness!  I almost equate this with Oxalis corniculata in terms of
> weediness.  

A friend who is a great gardener, but has a bad back and so can't weed
much, uses this  in both the white and pink forms as a weed-excluding
ground cover. She gave me plants of both sorts, but they failed to
establish in my garden and I am looking for more.  It does occur as an
occasional weed in my district, but I haven't come across any recently.

> The same applies to Corydalis lutea, which although attractive with
> greyish, delicate, fern like foliage and masses of bright yellow
> 'cigars', rapidly seeds itself about and quickly crowds out anything
> less vigorous.  A few weeks of inattention, nearly cost me several
> clumps of the diminutive, chocolate leaved geranium - G. sessiliflorum
> 'Nigrum', due to tiny seedlings of Corydalis creeping in unnoticed and
> then growing away suddenly at the expense of everything else.

As I wrote in another posting this doesn't like me at all, though C
cheilanthifolium really likes me a bit to well.
> 
> Another thug which give me a real headache is the so-called
> 'Kenilworth Ivy'  or 'Ivy leaved Toadflax' -  Cymbalaria muralis.  I  Once it gets a hold, you can never get rid of it
> and although it is well behaved in the hot, dry impoverished
> conditions of a dry stone wall, once it roots into half decent soil
> with a degree of moisture, its grow is rank, rapidly smothering nearby
> plants.

I agree this can be a thug, but great when it sticks to walls and I
don't rate it much of a pest really as it is so easy to pull out when it
encroaches on its betters.
> 
> The only one which is 'thuggish' to a degree, but is allowed to invade
> from outside, is the little Mexican daisy - Erigeron mucronatum.  It
> rapidly colonises wall and cracks in paving, but I rather like the
> white flowers which rapidly age to deep pink and so far, it has not
> been excessively difficult to eradicate where it is unwelcome.
 
Again, very nice when it sticks to walls, but it has taken to invading
my scree bed and there it is a real pest so I think its days in my
garden are definitely numbered. Incidently, while I can just about
justify growing it here in the south of North Island, it is a proscribed
weed  in the warmer areas further north, as it has taken to invading
native bush, and it is no longer sold in nurseries for that reason.
> 
> I wish the same could be said of one of the new varieties of
> Tradescantia that has become quite popular in recent years.  I
> originally planted Tradescantia albiflora 'Maiden's Blush' in a
> hanging planter where its intense magenta pink and white leaves on
> long trailing stems were very effective fro that summer.  The planter
> was left out in winter and the tradscantia survived.  I foolishly
> planted some pieces in the border and now it is the most thuggish of
> them all.  

I have had this or something similar crawling round under the benches in
my glasshouse for may years. It is a pretty thing, but there is no way I
would let it out of doors. One of the major weeds in shrubberies  and
borders in all but the coldest parts of New Zealand is the plain green
Tradescantia and it has also become a serious pest in many bush areas,
interfering with the establishment and survival of many of the smaller
plants. It is an appalling thing to get rid of, as, though the main bulk
can be removed pretty easily by raking, every morsel left around will
regrow and constant vigilance is needed if it is not soon to be as bad
as ever again. Even if one is prepared to use weedkiller, there is
almost nothing which will touch it without completely sterilizing the
area and its fleshy growth seems unaffected by a flame weeder. It is
also very difficult to compost, as it tends to grow again even after
being entombed in the middle of a heap. I have had success only by
keeping it in a closed plastic sack for several months until it is
finally debilitated enough for the compost organisms to get on top of.

Moira ( On a cold, wet winter's day where outside weeding has no
attraction!)
-- 
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata, Lower Hutt, New Zealand
(SW Corner of the Pacific Ocean)
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