Don't prune once a year flowering roses (e.g. banksia roses) until after flowering.

In frosty areas wait until after frosts before pruning.

Prune to:
- improve growth, vigour and flowering,
- remove damaged, compromised or diseased growth,
- provide a base structure for the new season's bud growth.

Pruning enhances the inherent characteristics of the rose, often with bigger and better growth and flowers.
(But it can't control height!. i.e. It won't make a naturally tall grower small.}
What to cut, and how the plant will react, depends on the plant's growing habit.

What to do.

It's all about the buds.
The buds are the growing points that determine how the plant grows.
Important considerations are: competition for resources between buds, and the power of (sun)light.
To cut or not to cut.
Do cut: damaged or diseased growth,
do cut: weakling shoots - they won't produce stronger growth,
do cut: inward pointing growth - it will have less light,
do cut: the length of a shoot to concentrate resources into the remaining buds.

All this will improve future growth.

Don't cut below the graft. (As if you would.)

Cut above a bud, close to the bud (10-20mm is OK.)
Choose an outward pointing bud if possible.

Pruning different styles of roses

Different rose varieties have different growing habits.
Pruning results in stronger growth with the same habit.

Roses with long stemmed flowers.

Roses that make long stemmed flowers.
e.g. Hybrid Tea, cut flower roses.

Hard prune to encourage long stems with large flowers by hard pruning.
Cut out weaker, less productive growth and cut other growth back hard. The aim is to produce bigger better stems and flowers by concentrating resources into the remaining buds.

Cutting 50%, 75%, ankle height, all work for this style of rose. They don't take long to regrow.

Bush roses.

Roses that make a bushy growth with flowers - often in bunches - on short stems.
e.g. Floribunda, some David Austin, shrub roses, rugosa roses, many others.

Prune to encourage a bushy type of growth. Thinning out weaker growth and cutting the remaining shoots by not more than 50%, will usually work well.
(Pruning harder, although not a problem, initially produces longer stems before it makes the shorter ones giving the bushy effect.)

Climbing roses.

Climbing roses make long branches.
Once a year flowering types will flower all over at once and then keep growing.
Repeat flowering types will flower at the end of a new shoot/branch, subsequently buds along that branch will develop lots of smaller shoots which make flowers all along the branch.
Leave some branches long so that they flower all along the branch.
Note the importance of light. Those parts that get the most light will dominate the growing and flowering. Prune to allow light in.

Standard Roses.

Standardised roses may be of the long stemmed or bushy type. If bushy they can be light pruned. If long stemmed it is best not to prune too hard.
Long lanky growth is often not desirable on a standardised rose, but often forgiven because of the beauty of the flowers. Cutting a long branch short reproduces the long growth - it's better to cut it long so that more buds compete, making less vigorous secondary growth. It will still be tall but bushier.

Weeping Standard Roses.

Weeping standard roses are climbing style roses grafted high.
They are pruned similar to climbing roses. Leave some branches long and open the centre to more light.
(Note that some weeping standard roses are once a year flowering - prune these after the flowering.)

If you get it wrong it's not fatal. You might stuff up some flowering or temporarily promote the wrong shape, but buds will regrow, the stonger growth will take over and you can give it another go. (Things that go wrong after pruning are usually a consequence of growing issues not directly associated with the cuts. So to all those husbands that get blamed after a prune - it's not your fault.)

- "cut first and ask questions later."