After behaving well for many years our bamboo plants have just started
shooting up all over the place in all the neighbour's gardens.

I have dug up all ours and I am about to put it in plastic boxes and small
plastic water cistern tanks.

I am trying to kill off all remaining bamboo leaves growing in the garden
with ammonium sulphamate and glyphospate, but i dont seem to be
winning......help !

With regards to the type of soil to use in the plastic boxes, I would prefer
it not to weigh too much and to be able to 'wash off' (since our soil here
is London clay and is like cement to get off the roots) easily if i needed
to take the bamboo out of the box in future to divide the roots.

My idea at the moment is to use half garden centre compost, a quarter sharp
washed builders sand from BQ, and a quarter john innes number 3, and to feed
with phostogen.

if there was any way to reduce the 'weight' and/or the 'cost' of the soil
for all the boxes that would be suitable for bamboo, suggestions would be
very welcome....thanks for any advice.