I have recently moved into a house that has a small patio area at the front
of it (15ft x 8ft). The previous owners had planned to put a hedge around
two sides of this area and have created a brick trough that stands about two
feet high and and one foot wide.. There is nothing planted in there at the
moment but I would like to put a hedge in, that will eventually ideally be
about 6ft or so high.

I had initially thought about planting Leylandii and checked out the section
in the urg faq. Would it grow ok in such a contained space, would the small
space for roots restrict its growth and would it break out of the trench? Or
should I try something else?

I know almost nothing about gardening, and this is my first venture at
cultivating anything other than a houseplant, so apologies if it's something
obvious

thanks for any advice

Paul