Saturday, August 16, 2014

How to prune a rose bush

How to prune your rose plants

Winter pruning;

For standard roses the best time to prune (in Melbourne) is late winter when the plant is dormant. I pruned my roses a few weeks prior to writing this blog entry.

Why do you need to prune roses?

  • To remove weak spindly growth and direct energy to stronger braches and therefore give a larger flower size.

  • To remove dead or diseased branches which can harbour pests and disease.

  • To direct the growth of the plant outwards to produce the classic vase like shape of a rose bush and also increase ventilation by eliminating inward crossed over branches

  • To shorten back last seasons growth by two thirds or maybe a little more to encourage regeneration and keep a more compact shape
Making the cut;

So you are ready to make your first cut. You will need a sharp set of secateurs and if you want to get really thorough you can sterilize the blade(s) with some Alcohol or bleach. Sterilizing them can help prevent the spread of diseases. Commonly it is taught that you need to make an angled cut 5mm above an outward facing bud. You want to cut to an outward facing bud to direct growth outwards and create what is known as a vase shape.

 Cutting 5mm above the bud is important as it prevents die back. Die back occurs to all the stem above the last bud which you cut to which is why a close cut matters

The theory behind why an angled cut is necessary is that an angled cut directs water away from the bud. Some people have told me they don't believe in angled cuts as they increase the size of the plants vascular plumbing and therefore encourages water to pool in the vascular entry points. Personally I don't worry too much about the angle and concentrate more on the position of the cut in relation to the bud.

The last point I will make is that if using bypass secateurs you want to cut with the blade facing towards the part of the stem you want to keep and the anvil facing the direction of the part of the stem you are going to discard (see picture below). This is to prevent bruising the stem / bud.

Summer pruning (dead heading);

Which is essentially dead heading old spent flowers from the rose bush. If you do not dead head the flowers then a rose hip will develop from below the spent flower. This has the effect of suppressing further flower bud development. I've always been told that when pruning off the old flowers you should go down to what is known as a five leaf set. People have told me that if you do that you should get new flowers appearing from the bud which develops from the base of the five leaf set. I'm not sure whether the science supports that theory but it was worked for me in the past. As I'm writing this during winter I can't provide any pictures for this procedure but I will write an entry in the Summer which includes pictures to help you understand this method.

Picture of a rose bush during mid - late winter in Melbourne. More specifically it is in the garden of my main workplace (one of many) which is the college called International House (Melbourne University). This is the 'before shot'.

Hopefully you can see important things in the picture below. The first is that I have the blade of the secateurs positioned on the side of the stem I want to keep and the anvil on the side of the stem I will discard. The second thing that I hope you can identify is the little bud which I'm aiming to cut roughly 5mm above.

This is the 'after shot'. It looks bare now but will look fantastic once it has new growth and flowers.

After a few weeks that little bud you pruned above should be putting out new growth like the one in the picture below which is a rose bush in my home garden. This particular but looks a bit rough maybe I should have sharpened my secateurs before pruning.

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