If your garden is small in size, this may be a bad idea. The shade and
roots can become a big problem. Think more latterally and consider
something lower and more restricted in root than a tree.
Phormiums can be great: get a large specimen (I can do trade deals) that
will flower next year. These are very dramatic and will not dominate the
garden as dfar as light and roots are concerned.
Neil

"Ramon A" wrote in message
...
We just cut a new bed (triangular with sides 20 ft, 12 ft and 15 ft) where
once was lawn and would like to make the centrepiece a standard decorative
tree or praps a large shrub. but with plenty of space below for planting
out. summer bedding then over wintering annuals.

the ground is good quality sandy soil well drained to the point of being
dry
most of the time - mid bedfordshire and with plenty of horse poo already
been added at the outset.

the feature specimin should be light in leaf and branch to give dappled
shade and top out at no more than 20 to 25 feet fully grown.

any ideas please?

rgds Ramon