It will never work.

Ulmus pumilla is a Pioneer Species, meaning that it quickly establishes it
self in the wild in recently disturbed/cleared areas, and is genetically
programmed to put everything it has into apical growth in an effort to beat
the other trees to the canopy. The result of this pre-programming is a tree
with a staggering growth rate and weak, brittle wood. Branches that are
broken (or pruned) simply abort in favor of growth elsewhere.

Dave

"Anderson" wrote in message
...
I have a row of siberian elm trees, 3'-5' tall, that I'd like to prune as
hedges, they don't seem to be bushing out enough, although they have been
cut back before. Some of the trunks to the first branches are about 1' .
Any ideas would be appreciated.
Thanks
Karen