"mcloone" wrote in message
om...
Ok,
the gardener seemed helpful at the start, but the owner of the hedge
expressed similar concerns that the hedge was now thin. The said
gardener charged 150 quid to spray cut branches with "fungicide". He
said this would ensure it turns green again. I now think the
gardener
was just trying to make a fast buck.

That is as clear as a bell, from that last sentence.

I have since discussed the hedge with a garden centre owner. She
doubts that there will be regrowth and also said that because the
tree
root system will have extended into my garden i will not be able to
grow anything underneath them. I've noticed that our grass did not
take well underneath either. The leylandii suck all the goodness
from
the soil apparently.

That is much too pessimistic an attitude. It is possible to load your
soil with "goodness" faster than the Leylandii will abstract it. Feed
the soil regularly with Growmore and mulch it thickly with spent
mushroom compost or Council compost or your own compost.

One thing suggested was a "Montana Clematis"
which is quite prolific and may compete with the trees.
I understand I can cut the roots on my side of the fence. If I cut
the
roots and place some kind of barrier to prevent the roots crossing
over again and fertilize the soil on my side, should I be able to
grow
what I want? What might an effective root barrier be?

Don't bother playing with the roots other than cutting the ones which
interfere with your planting plans. Just be a little more generous
with fertiliser and compost than you would otherwise have been and all
will be well.

[snip]

Franz