How to Prune and Trim South African Plants

Before you amble out into your garden and start pruning, trimming and cutting back, there are a few things to consider, such as what tools will I need. Here are the essential pruning tools you will need:

Pruning tools

  • Secateurs – also referred to as clippers – are among the most popular of pruning tools. You might not have a lopper, but you will almost certainly have a pair of secateurs. Depending on your hand strength, you can cut through stems, branches and twigs up to about 16mmØ.
    There are three basic versions of secateurs and they are all intended for use with one hand:

    • The bypass acts in the same way scissors do. Two sharp blades pass each other and cut whatever comes between them. This version is a good choice for growing stems and also when pruning back old growth, on rose bushes, for example, where you want a 45° cut above new buds.
    • The anvil version. In this instance, a sharp blade closes down on a flat metal surface (hence the description ‘anvil’) and this version is a good choice for removing old and dry material.
    • The ratchet version is similar to the anvil pruners, but instead of a direct action linked to the closing of your hand, this version has a ratchet that allows the user to make the cut in smaller increments. It allows the user to exert a lot of force without getting a cramp.
  • Loppers are essentially secateurs with far long handles and are designed for use with both hands (in fact that is the only way you can use them effectively). The long handles allow the user to exert a massive force, and hence these tools are used on thicker vegetation and can handle branches up to 25-30mmØ with relative ease. Loppers are great for pruning back tree branches – including those of fruit trees. Loppers are available in the same versions as secateurs – namely bypass, anvil and ratchet. Some are also geared, with the one blade or the anvil essentially remaining stationary while the upper blade, with a toothed gear on the fulcrum, is acted upon by a second toothed gear attached to the handle. This multiplies the amount of force the user can exert.
  • Hedge sheers are another very common pruning tool and as the name suggests are designed primarily for trimming hedges and the thinner stems uses on branches, bushes and shrubs.
    The blades are usually of the bypass design and might have an undulating ‘wavy’ cutting edge on one or both blades. Hedge sheers also often have a cutout close to the fulcrum so that the user can cut through thicker branches, up to 10-15mmØ or so.
    Using secateurs and loppers…
    As is clear from above, both of the above use compression, either by the user’s single hand or with both hands, to exert a cutting force on the plant material. They are limited in use by the user’s strength, and also by the thickness of the material to be cut, so don’t strain either your hand or you arms, or possibly the implement itself by trying to cut through much thicker material. When it becomes a real challenge, switch to:
  • Pruning saws are available in a variety of designs. There are curved blade versions designed for use with one hand, to bow saws – available in a variety of blade lengths – that will handle branches up as much as 100mmØ or more.
    They more often than not have very coarse teeth, offset slightly so that the cut is slightly wider that the blade itself – to prevent it becoming jammed in the cut and they are designed for the really thick material and not for branches of a much smaller diameter. Bow saw blades can be changed when the existing blade becomes blunt.
  • Pole pruners are essentially secateurs and a saw assembly mounted on a pole. The secateurs are operated by a pulley system with a cord down to the operator, and the upper blade has a sharply hooked profile that allows the used to hang the implement on the branch to be cut, and then pull down on the cord. This moves the blade up into the underside of the branch, cutting it. In some versions the user can adjust the positioning of the operating arm, to increase or decrease the cutting force on the blade. The double pulley system is a ‘force multiplier’, enhancing the amount of force the user can exert. Pole pruners are also supplied with a curved blade saw that allows the user to cut even thicker branches. The beauty of the pole pruner is as the name implies, it is mounted on a pole. Some come with an extendable pole, others not. The pole can be virtually as long as the user wants, and can be as much as 2.5m – that allows tree branches as much as 3.5-4.5m from the ground to be cut away – without the operator ever having to leave the ground.
  • Electric hedge trimmers may be mains or battery powered and comprise two blades, sometimes one stationary, while the other reciprocates back and forth as high speed. The blades resemble a double-sided comb and make short work of excess growth on hedges.
  • Chain saws are highly effective in handling branches up to as much as 300mm or more – so that can include tree trunks. They are available in either petrol or electric versions but require great care when operating them. If used incorrectly or carelessly they can result in very severe injury.

Safe operation of pruning tools:

As with any implement designed to cut, you need to follow the manufacturer’s instructions regarding using pruning tools. When using any mains-powered electric tool…

  • Always work away from the power cord, never towards it
  • Ensure you have a sure footing
  • Never try to over-extend yourself, rather move the ladder – if you are using one – to a new position where you can easily reach the material you are work on.
  • In the case of main-powered electric tools, do not use them in the rain, and for safety sake, use them only one the early morning dew has burned off. Dry surfaces are your friend.
  • Always wear appropriate safety gear. Gloves, protective eyewear (cutting to plants results in sap oozing out and if during the cutting operation any is flung into your eyes, you will know all about it), hard hat etc.

Caring for your tools

It is always important to take care of your tools. Learn how here:

  • Keep them clean.
  • Ensure all blades are sharp, using the tool when the blade/s is/are blunt not only increases the amount of effort you need to make the cut, but can also result in damage of the tool.
  • Keep them in proper working order – replace blunt or rusted blades and any frayed or damaged electric cords.
  • If you are working on a diseased plant, before moving on to another (healthy) one give the blades a good wipe or even better a good wash (so you reach every surface) in alcohol or household bleach so you kill off any dangerous organisms that might be lurking on the blades. Then rinse the blade/s in clean water, dry and use.
  • Wipe them down after every use with a rag and before storing them for a longer period, give them a good clean and protect the blades with a protective wax coating, oil, petroleum jelly or moisture retardant coating.
  • Oil or grease moving parts on a regular basis to reduce wear.
  • When storing away bow saws, either turn the blade inwards or slit a length of hosepipe along its length and slip, it over the teeth.

Now we get to the actual pruning and bearing the above-mentioned points in mind, assume in each case the basic preconditions are met before every pruning or trimming job: The tools (secateurs for thinner material, loppers for thicker, saws for the really formidable) are used and they are clean, sharp and fit for purpose.

Pruning roses

    Before you start, take time to check out the plant in its entirety so that you have a good idea of what needs to be done, and where – so you don’t end up with a botched job.

  • Use good quality bypass-type secateurs that make a clean cut, rather than the anvil type that tends to crush the cane at the cutting point. You might need loppers for thicker canes, and the same advice applies.
  • Wear gloves
  • Prune from the base of the plant.
  • Prune away dead wood, rose pips etc.
  • Prune to open the centre of the plant to allow more light to penetrate.
  • Prune to open the centre of the plant to light and air circulation.
  • When cutting, do so at an angle of 45° about 6mm above a growing bud or node and try to ensure that that bud is going to develop towards the outside of the plant.

A good time to prune is at the beginning of spring, when the buds are beginning to appear.

Pruning lavender

As to when to prune lavender, some gardeners suggest late summer is the best time, others suggest spring is the time.

Pruning hibiscus

Hibiscus produces what are called terminal flowers – flowers that grow on the end of the branch therefore the more branches your hibiscus has, the more flowers you will enjoy.Many gardeners suggest the best time to prune is early spring.

Where and how to prune applies as per the roses. Generally, you want to open the plant, remove any dead or diseased parts and also shape it for best effect.

Pruning shrubs

Remove dead or diseased parts and make sure you do not prune below what is called the ‘branch collar’ – it’s that ring of bumpy material where a branch meets the main trunk.

As with roses, cut at an angle of 45° (this allows moisture to fall off, whereas a straight cut could cause water to pool and possibly cause problems) above an outward-facing node or bud.

Pruning proteas

Some experts suggest that when pruning young bushes, prune the tips in spring and late summer whereas in the case of mature plants, you should prune immediately after flowering.

Remove flowers once they have lost their colour, but leave about 100mm of stem on the plant and avoid cutting back too far as you can cause a setback or even kill the plant.

There is a great variety of proteas out there the best option is to contact your local nursery or even Kirstenbosch to get expert advice.

Pruning trees

Your first action is to select the branches you want to trim or remove. This could be due to a branch or branches being disease, overhanging the neighbour’s property, overhanging your swimming pool or simply that you want to improve the tree’s overall shape.

  • Remove dead branches close to the trunk.
  • In the case of large branches, begin form the far end, first removing the leafy material, then the thicker offshoots and then working you way back to the trunk.
  • Removing short sections of the thicker part of the branch while it is still on the tree can be easier than removing the whole branch and then trying to cut it into shorter sections for easier removal.
  • If using a ladder, make sure it is on a firm surface and do not try to overreach as you operate along the branch – rather move the ladder.
  • Ensure that no part of the ladder is directly below any part of the branch on you are working on.
  • Working on a tree during its dormant season will reduce the number of leaves you will need to pick up afterwards.
  • If you think that trimming back a tree might be beyond your capabilities, call in the experts.

How tall is that tree?

If you are planning on felling an entire tree, you might want to know its height. Here’s an easy way to get a pretty close approximation:

  • Fold a piece of paper into a triangle create a 45° angle.
  • Holding the paper at eye level, make a very visible mark on the tree’s trunk at eye level and then walk backwards on level ground away from the tree, keeping the bottom of the triangle at eye level and on the mark on the trunk.
  • Still keeping the triangle in position, periodically sight along the hypotenuse of the triangle and stop walking when, with the bottom edge of the triangle still on the mark, the hypotenuse meets the top of the tree.
  • Measure your distance from the trunk and add the distance from ground level at the foot of the trunk to the mark you made.
  • The two added together is the approximate height of the tree – now you work out the best direction to fell it without risk of damage.

Pruning South African Plants

The basic set of tools that you need to handle just about every pruning or trimming task in the garden. Not pictured are any electric tools or a chainsaw, but on the vast majority of occasions, you would be using any of the tools pictured.

Pruning South African Plants

Secateurs – this is a bypass version – will handle a variety of tasks.

Pruning South African Plants

Saws for use on thicker branches range from this – a small but very effective saw mounted on a pair of secateurs – to much longer single blade saws and bow saws.

Pruning South African Plants

One of the reasons for pruning is to remove dead or diseased parts of the plant – in this case, on a lemon tree.

Pruning South African Plants

When pruning roses, the aim is to remove dead parts but also to open up the middle of the rosebush to more light.

Pruning South African Plants

Note that the cane has been pruned at an angle of 45° (it sheds water, reducing the likelihood of water pooling as possibly resulting in infection) and about 6mm above an outward-oriented bud.

Pruning South African Plants

Deadheading a rosebush.

Pruning South African Plants

A crafty way to ascertain the height of a tree with reasonable accuracy – provided you do it on a level contour. So you might need to walk about a bit first before you find the ideal. When you can sight along the triangle with your eye so that the bottom horizontal edge is on the mark you made on the tree trunk at eye level and the hypotenuse lines up with the top of the tree you then simply add the height to the mark on the trunk, to the distance you are from the tree trunk – and that approximates to the height of the tree.