"Tahi" wrote in message
o.uk...
Do glyphosate based weedkillers only affect green tissue? In other words
can I carefully spray the ground elder without seriously affecting the big
mature tree paeony growing in the middle of it?

Glyphosate is absorbed through leaves, not woody tissue. It is inactivated
by clay particles in soil.

But if sprayed onto bare wood, and the weather remained dry, it is possible
it could be washed onto sprouting buds lower down the stem when it rained.
It's extremely unlikely, and the likelihood of a sufficient amount being
absorbed to do any damage is very low.

If you are concerned, just wrap some only polythene round the paeony stems
before you spray and wash it off the outside after a couple of days and then
remove the polythene.

--

Jeff