Well one the last part, we looked at the science behind making pruning cuts and best ways of pruning using secateurs and loppers, this week we shall look at using the power horse of hand tools, yes the pruning saw! So what is a pruning saw and how does it differ from say a carpentry saw? Well it’s a much stiffer blade that those types of saws and most of the time cut on the pull. Some can be folded up to fit into your pocket or a fixed blade. Pruning saws are used to prune anything bigger than 15mm and up to well as big as you can cut! A bit like using secateurs, theres no right or wrong ways but there’s always better ways to reduce damage or risks to the tree or plants. First thing is to get the sharpest pruning saw you can get with a sharp clean blade, over the years I have found Silky pruning saws the sharpest and even with these, I tend to change the blade every year so I am using the sharpest I can.
Now the angles of cut depending if the buds are alternate or oppersite are the same as for using secateurs on wood up to a couple of years old but they are a little more difficult to see in the older wood, almost looking for wrinkles in the Wood is almost a sign that buds are there hidden. That said in wood over 25mm thick, I prefer to do a straight cut across. The reasons are simple, the surface area on straight cuts are much smaller than cuts made at an angle, which means the plant has a smaller area to heal over. That even means on the junction of bigger branches. The pruning cut on these bigger branches to the main stem used to be done at an angle on the stem, the angle of the cut was always done just above the ridges or collar on the stem. It was thought these would heal quicker but it’s not really the case as the straight cut will heal a lot sooner.
Removing larger stems using a pruning saw is always best done in stages to reduce the chances of the branches tearing down the stem and causing a bigger damage for the plant to repair. Best way is to reduce the weight of the branch by either putting a cut on the underside of the branch to about a 1/5th of the width of the branch and at least 300mm from the trunk and then the main cut about 50mm above this. If you leave a bigger gap, the branch tends to trap itself in the bottom cut and doesn’t fall cleanly. The branch should snap cleanly off and fall down to the ground, then you finish off the cut neatly on the main stem . That cut is ideal for most pruning cuts. If there’s something underneath you that you don’t want the branch to drop off suddenly and hit, you can cut all the way though in one cut. This at times can cause a tear underneath the stems so I would make this cut at least 1000mm from the main stem in case the cut tears down. After this cut has been made and the branch had fallen down or been grabbed, the next cut needs to lighten the weight on the branch by cutting it down to 500mm before cutting the branch off at the main stem. All the cuts are pictured below
Last main pruning cut is removing stems from the base of shrubs and the key this here is to get the cuts as low as possible. Any stubs left will make the base of the plant look ugly and also mean next time you cut a stem out, you can’t get close to the base and it ends up even more snaggy
one other thing I don’t do is paint the cut area with wound paint. I prefer to let the wound heal naturally and found that the treatment tends to seal in the moisture and cause rot quicker
Picture of a clean drop pruning cut
How it worked
Cutting straight through
A straight though cut that shows the damage that it can cause
The growing collar as described in text