If this willow is the potential giant I associate with pond-side planting,
it is possible it has outgrown its pot .. used up the soil until there is
nothing left to retain water. Although it seems unlikely after just three
months, there must be a considerable root mass to support that extra 2' of
growth. If you investigate the rootball, you will learn how quickly the
root is spreading, and even if it is damaged. It may help to do some
remedial root-pruning if you want to keep it in the same container, or pot
on to a bigger pot if you want natural growth.

I'm sure your feeding regime is appropriate since you have several other
willows in pots, so it can't be starvation.
My only other guess is that it may have been 'watered' by something with
four legs. If this is likely, then a good flushing out of the soil with
more water will continue the dilution process.
It would certainly help to keep the tree shaded until its health improves.

Sorry can't help further without more clues, but will check my RHS guide for
diseases of Salix when I get a minute.
SPIDER

Earnest Trawler wrote in message
...
Thanks for your reply Spider.

I have been watering it every day untill water runs out the bottom of the
planter. It is grafted, I had not thought of that, the graft looks to be
fine. It's grown quickly from 6 feet when bought 3 months ago to about 8
feet and the trunk has thickened quite a bit, it seemed to be doing very
well up untill a few days ago.

Earnest Trawler

"Spider" wrote in message
...
I am not a willow expert, but this sounds like drought to me. If you're
sure you're giving it enough water, is it possible that the water isn't
reaching the tree efficiently. Is your tree grafted, for instance, and
if
it is, have you checked that the graft/union is still intact?
SPIDER
Earnest Trawler wrote in message
...
I have a salix x sepulcralis chrysocoma in a large planter. A couple
of
months ago it was affected by scale, which I manageed to treat
scucessfully,
now it has another problem. Almost half the leaves have gone very dry
and
curled up, some have started falling, it's happened very quickly, in
the
past 4 or 5 days.

It's planted in potting compost with pearlite, gets plenty of water
and
a
regular feed. I have other ordinary willows in pots which are all
doing
fine. I am wondering if I am doing something wrong, or if I have just
bought
a dud tree.

Any advice would be much appreciated.

Earnest Trawler