On 19/04/2020 09:27, Another John wrote:
Hi

For the last few years we've had [what I have identified as] speedwell
in our lawn. I annually treat the lawn with "Weed and Feed", which
seems to deal with the usual weeds (buttercups, dandelions etc) but the
speedwell seems to shrug this off, and it has got worse and worse every
year.
In the last six weeks uI've treated the lawn three times .. the
speedwell has slight burning arond the edges of the leaves, but the
plants themselves seem to be burgeoning.

Any other recommendations for dealing with this?

Learn to love wildflowers in your lawn?

I don't particularly like the pristine sterile Chemlawn look myself.
(yes that is a real US gardening brand - clue is in the name)

I only persecute dandelion and buttercup in lawns I look after. I don't
let excessively large patches of daisies occur but a few look nice. YMMV

The weed and feed that I've been using is called Vitax Lawn Clear,
active ingredients appear to be Phosphorous pentoxide and Postassium
oxide (could be wrong about that since I am not a chemist, but they are
the only dodgy looking things listed).

You want a broadleaf specific herbicide of which the last remaining one
on sale to the general public is now branded as "Weedol for Lawns" is
mostly MCPA (it contains none of the ingredients of classic Weedol at
all). It is a triumph of brand marketing over common sense.

https://www.amazon.co.uk/Weedol-N-A-...dp/B07BRNSH6J/

I use it to spot weed against lawn dandelions at this time of year to
prevent them from flowering ans setting a new generation of seedlings.

BTW MSDS I found says it has a trace of Clopyralid in for thistles
which means its a bad idea to put grass cuttings on your compost heap
for a while after using it. It is rather too persistent.

https://en.wikipedia.org/wiki/Clopyralid

Supplementary question: this group used to be very busy with gardeners,
and now we are reduced to what appears to be about a dozen ... where's
everyone else gone?

Out gardening? Various hubs. Usenet is now a very minority interest.

BCSS has for example now taken to zoom for national virtual meetings
since physical ones are no longer possible. It has had an interesting
side effect at least for the first few some international experts have
given their services free to help the world community of cactophiles.


--
Regards,
Martin Brown