In article , Stan The Man
writes
I've given up on trying to rescue a 10 x 8ft area of lawn at the bottom
of my garden. It just wants to stay wet for 11 months of the
year...thanks to my deep Berkshire clay. It had anyway become populated
by boggy weeds so I have decided to let it be a bog garden. I didn't
like the weeds though so I have removed the topsoil, complete with most
of the weeds and roots and what turf there was and I now have a clear,
brown patch with puddles. I would like to beautify a bit while planting
some bog-lovers and would be grateful for advice.

Firstly, I'm all ears for plant recommendations. I want some height
mixed with some colour, but I don't like anything that looks like giant
rhubarb (threw some of that away). I guess I want it to look at least
semi-cultivated/planned rather than some bog gardens that I have seen
which are more or less overgrown with the kind of coarse leaves that
I've just dug up.

Marsh marigold, Caltha palustris - and you can get double flowered
variety - glossy leaves and big buttercup flowers.
Ragged robin - delicate plant with finely divided pink flowers
Primula rosea - rather aggressive pink colour - seems to take as much
water as you can give it.
Various garden varieties of purple loosestrife (Lythrum) and yellow
loosestrife (Lysimachia) will grow to 2-3 ft.
Astilbe likes moist - don't know quite how wet it will take it
Meadowsweet - divided lea ves and big frothy clouds of white flowers.

Next, should I improve the soil or just leave it be? It can clearly
support healthy weeds.

Leave it be.

Presumably I will need to make planting holes - but I'm thinking these
will just fill with water. Maybe I should plant in baskets?

No, just plant in the puddles ;-)

Should I edge the area, maybe with rocks or sleepers and/or some
marginal plants?

What is next to it? You could have a nice gradation from boggy to
moisture loving. But if a lawn is next to it, then you'll want a mowing
strip. Could be worth having slabs (york stone or similar) since you'll
want to tend the garden now and again, and slabs will enable you to do
so without getting your knees wet and cold.

And to prevent the weeds returning could I cover with a
weed-suppressing fabric, mulch and/or gravel/slate/shingle?

No - it would be out of keeping with the bog garden look. Once your
chosen plants are well established, other plants will find it hard to
compete.

And finally, the supreme irony: for the one month of the year when this
area dries out, should I add water?

Possibly! Does it get bone dry or merely dry-ish? Natural boggy areas
have changes in water level, so the plants should be able to cope. See
how it goes. If things are wilting, then water.

--
Kay
"Do not insult the crocodile until you have crossed the river"