On 24/10/2014 16:13, Nick Maclaren wrote:
In article , Malcolm Race wrote:
I have been lurking here for a few weeks and would now like to tap your
not inconsiderable collective knowlege.

I have two problem weeds, one in each of my two lawns. Both have been
treated with Verdone and a spray on spot weeder with no effect. The
first is
https://www.dropbox.com/s/41828lh67k..._1921.JPG?dl=0
https://www.dropbox.com/s/zj1bm8c9rr..._1922.JPG?dl=0

This one has purple flowers looking somewhat like clover

Self-heal. Dig it up, religiously. That's not too hard, as its
flowers stand out well. It's very attractive, and a functional
lawn plant, but is much darker than grass.

I let small amounts of it grow in my lawns. It isn't too invasive and
has nice flowers. But then I don't like a monochrome green lawn. I only
really draw the line at dandelions - they have to come out. Verdone will
kill it and a good raking and hand weeding will easily thin it out.

and the second is
https://www.dropbox.com/s/tudftpbyxs..._1923.JPG?dl=0
https://www.dropbox.com/s/5qeeo1g96g..._1924.JPG?dl=0

The foliage is purple and seems to shed water - it spreads readily.

I appreciate that one answer is to dig it all up and re-seed but the
second covers a considerable area and appears to spread from the
smallest fragment

Oxalis (sorrel). I am not sure which. Try nuclear weapons, or
glyphosate and often.

It is very common around here but it doesn't cause any bother at all in
my lawns. Paths and everywhere else but not in the lawn. I'd have
expected Verdone to kill that too but you might have to use a bit more.

Try a weed & feed treatment in spring. Grass should be able to out
compete the oxalis in a healthy lawn.

--
Regards,
Martin Brown