fast growing shrubs

The trouble is that fast-growing shrubs don't just stop when they reach 5'! Please would you give some more info about soil, which direction the fence faces, etc. This would help in giving you suggestions.

Buddleias are suitable. you want a dwarfer one try Nanno Blue. A nice evergreen is Lonicera nitida, there Is a Golden form Baggessons Gold which is a little slower but makes a lovely hedge up to 6ft.

yeah all these factors are important, you may face a major maintenance issue if you go ahead and plant fast growing shrubs. Something that is really fast growing may become more of an eyesore, closer to a weed then a garden shrub. Why not grow a nice evergreen climber on it, like an ivy or an evergreen variety of jasmine.

For the shrubs depending on the conditions, you could look at escallonia, holly, euonymus,Eleagnus pungens and check out Cupressus glabra also. Ok go see which ones you like, however to make sure your shrub is fast growing you are going to have to make sure you are planting it in optimum conditions, so take light, soil, temperture, water and atmosphere factors into account to get the quickest, fastest results possible.

OK hope this helped.

I agree with spritzhenry so why not go for something which will cover the fence quickly but which you can get rid of once the slower growing shrubs have established themselves. Too fast and you risk having an uncontrollable hedge rather than hiding a fence with a few selected shrubs!
I've used evergreen winter-flowering clematis to hide my fence but it is quick slow for the first year or so.