Hi there and welcome to Goy, maybe a hydrangea would be nice, surrounded by various grasses and ferns, these would be easy to keep, also hardy geraniums are good, heucheras come in all colours too. Perhaps you could put a photo on here and we could visualise your plot!

I hope you don't actually mean plastic sheeting underneath your gravel, but do mean membrane instead. Plastic won't let water through, so you'll have a waterlogged gravel area if that's really what you've used.

Which way does the garden face (sun or shade?), where are you in the UK and how big is the garden?

Remember that membrane and gravel do not mean you will have no weeding to do, as weed seeds still blow in and grow. Looking forward to seeing your photo.

Bamboo, thanks for reply will check on membrane putting it down now, garden is about 4x4m and face south so gets sun

Added to GoYpedia Weed Suppressing Membranes..

click on those words below "Featured On" top left.

...that might give you more ideas ..

I hope this helps :o)

Oh well, southfacing - Photinia Little Red Robin or, for a larger plant, choose its cousin, Photinia Red Robin. Brachyglottis, Lavender, Santolina, Hebes (Midsummer Beauty, Autumn Glory, Youngii, but don't plant these till Spring), Yucca flaccida Golden Sword (don't plant till Spring). All these are evergreen, and all small to medium sized shrubs. Deciduous ones worth having are Spirea 'Goldlame', Berberis 'Admiration' or 'Bagatelle', again medium to small shrubs. Halimiocistus, Helianthemums, Ophiopogon nigrescens, Arabis, Aubretia all good for groundcover. Perennials, if you want any, Campanulas such as C. persicifolia, C. muralis.