Nick Maclaren wrote:
But it's pointless, anyway - grass is very sensitive to glyphosate,
and is killed by a single application. MUCH easier.

Thanks. I can see that being true. And Glyphosate doesn't lower the
quality of the soil for the plants that I'll then put in, presumably
after a certain waiting time? How long after?

Well, somewhat, but watch out. Many or most of the evergreen ones get
big, quite rapidly, in suitable conditions. How big? 30' high and stems
9" across, with roots going down well over a foot. You would be WELL
advised to use only ones that are guaranteed to stay small.

And thanks for this too. I'm constantly amazed at how the human mind
cannot conceive of all factors at the one time. (We really do need
computers!) You're absolutely right. The splendid rhododendrons we
had in West Wales were only about 9 feet high but they had trunks it
would take you two hands to get around, say, 5 inches diameter. So,
yes, it's difficult to believe a trunk that thick would not have roots
that would resist descending further than a foot below the surface!

Maybe I could try the bonsai option? Embed four or five 1 foot strong
ceramic tubs in the soakaway, just so that the rims aren't showing, and
plants rhodies in them. That way the area might just become
successfully bushed while the roots would be contained?

What do you think?

Eddy.