I have 2 rose bushes in my garden, one seems to be a general bush shape - the other tends to grow upwards only, though it isnt a climber or a standard rose with a "stem". When should I prune them??
There seems to be 2 schools of thought. Either at the end of the season, as tonyav says, or when I tend to do them, which is in the Spring when the danger of frost is over.
To be honest they tend to be hardy plants, you can probably get away with it any time, at your own risk.
To be honest you can prune them any time from late autumn to spring and they will survive. I did mine in January and cut most of them back really hard. They are difficult things to kill!!
I would say generally February to March for bush roses, and late winter for ramblers and climbers to stop them getting damaged in the wind.
You can prune roses any time from Autumn until they start to bud. However I tend to give mine a prune every time I dead head them when they are in flower, I always cut the dead head back to an outward facing bud, to encourage fresh growth and hopefully more flowers. Roses are as tough as old boots and are very difficult to kill.
Personally I wouldn't give them garden space
Dig them up, throw them away
Check the RHS site for ideas for colour ,scent ,impact ... You could do much better , IMO