Buddleia davidii or one of the shrubby Lavateras, such as 'Candy Floss - drawback is, both will need cutting down in March or April each year, so that means no foliage for about 6 weeks afterwards. Lavatera will grow to about 6 or 7 foot in a season, Buddleia to about 10 feet.

Escallonia is a small leafed evergreen with white or red flowers in summer and grows quickly. Very tough plant that grows almost anywhere. If if goes too tall or a bit leggy can be pruned to give it more shape and make it more bushy.

Photinia Red Robin grows quite fast, is bushy and would make a good screen. No flowers though, so you might need a Clematis, for example, as well.

Actually it does flower, Sheila, and very nice it looks too when it does - but it only does it if you don't keep it pruned.

Many Ceanothus grow fast, "Concha" for one. Evergreen with lovely blue flowers but these are in spring, not summer.