It would help if you said where you are in the UK - the temperature difference between, say, Yorkshire and London is enormous, particularly during winter. I'd also ask whether there's a wall or fence between your garden and the street and how high it is if so.

Hi Bamboo, thanks for the speedy answer, i live in Northern Ireland and it can get mighty cold. & no, no wall or fence, the area is beside a driveway made of tarmac and also borders a concrete path in front of the house, the area is a triangle shape roughly speaking.

As you only want one plant, it needs to be interesting or attractive most of the year, so provided your soil isn't totally alkaline, I'd go for a Pieris - either P. 'Forest Flame' or P. japonica 'variegata'. Both are slow growing, although the variegated one is even more so - ultimate height for Forest Flame is 7 feet after 10 years.

Thanks for that, i will try that suggestion i love colour so this one sounds just the ticket. Speak soon.

Pieris needs acid soil as Bamboo says, so dig out a big planting hole add lots of ericaceous compost.