Winter is here - a time when most garden plants are less active, making it the best time to prune. Pruning is a process of renewal and without which many plants will deteriorate. We prune plants to improve their performance whether flowering, fruiting, removing unsightly dead branches or inflorescences, or to emphasize their natural shape. There is also formal shape pruning such as fences or hedges that require more frequent pruning.
Some plants respond very well to pruning and others less so. Bonsai growers use the pruning process to create the illusion of age. For them, pruning has become a passion and aside from emphasizing the natural tree shape, they also prune and shape their trees as nature does to create an illusion of age and of being shaped by nature. An artificial piece of nature! The Japanese have transformed the pruning process into a fine art and they put incredible effort into this process, even some of their large trees are shaped and pruned down to the finest detail.
Pruning is very enjoyable, also waiting for the results. Enjoy the pruning process and put your plants to the test, and through this process, we learn and get the hang of it.
To better understand pruning we need to look at the plants in their natural environment. “Unknown unloved” and if we understand natural pruning in the plant's environment we will also enjoy the process more. Do not be afraid to start pruning. Nature's resilience is greater than our pruning mistakes.
In this article, we take a closer look at pruning, both native and exotic garden plants.
If you follow the following four principles, you will quickly become a pruner.
1 | Keep the process as simple as possible.
2 | Prune only if necessary, with the correct results in mind.
3 | Consider the plant's natural pruning adaptation (fire, game, wind etc.) in their natural habitat.
4 | Do not throw away the prunings. It comes from the ground and can be recycled by putting it back.
PRUNING IN NATURE
All plants in nature depend on a natural pruning process. There are mainly four types of pruning in nature.
In coastal sections, on the seafront, plants are neatly pruned in a low cushion-shape by the salt-laden wind. The plants adapt to it. Then there is the unexpected pruning of storms that sometimes tear big trees apart.
Fynbos is pruned infrequently but drastically by fire in late summer. Not all fynbos plants burn to death, there are those that are adapted to just form new shoots from a woody rootstock. The King Protea (Protea cynaroides) and Fire heath (Erica cerinthoides) are good examples and sprouts out after a fire. Bulbs also sprout again after fire-pruning. However, there is a large group of fynbos plants that are so adapted to fire that they come up from seed again, the reseeders.
The Eastern Cape thicket, bushveld and karoo have been adapted to game pruning. Game pruning is a type of destruction pruning that takes place continuously and not once like fire. Spekboom (and many other shrub and bushveld plants) respond very well to shape pruning, such as fences. In the wild, the elephants prune these shrubs from the top, turtles from the side and bottom. As they feed, the branches that fall to the ground take root again and the plant uses its fleshiness to form lateral roots to reproduce vegetatively.
Many bushveld plants have been adapted to a combination of fire and game pruning. One species the ‘wonder plant’ or ‘Aaron's staff’ (Tinospora fragosa) uses self-pruning by cutting off some of its brittle branches from the mother plant, but instead of dying, the fleshy branches each form a survival root that grows up to 8 meters to the ground to re-root the plant.
Elephants love to eat the Star chestnut’s (Sterculia rogersii) water-rich fibrous stems and leaves. The plant has side branches that are easily pulled out of the main stem without tearing off pieces of bark and damaging the plant. Where its branch grows out of the main stem, it has a weak spot like a gecko's tail, and in this way the plant has adapted to elephant pruning and large game, thus donating its branches and surviving more efficiently.
On the highveld, we have frost or cold pruning. Most perennials and bulbous plants are cut down to the soil surface by the freezing process only to emerge again in the spring.
PRUNING IN THE GARDEN
Evergreen ornamental shrubs and trees
Do I have to prune everything? It is not necessary to prune everything, just where necessary and even if you make a mistake with pruning, plants recover quickly. If you were a little over-enthusiastic and killed the plant, just plant one again and learn from your mistake. Never give up.
Slow-growing evergreen shrubs need almost no pruning, just remove dead or diseased branches. If you are unsure, leave it until you feel more confident.
Trees usually need less pruning than other plants. First, remove all dead or diseased branches. Prune close to the main stem and do not paint the pruned parts. Do not leave short stumps, it looks unsightly. Remember that large branches are heavy and when sawn can tear the tree's bark into strips, so make a cut at the bottom of the branch first to avoid tearing. Prune to emphasize the plant's natural shape. Research in Europe and the US has revealed that sealing wounds keeps moisture in the wound and gives fungal spores a chance to germinate. Have you ever seen a giraffe running around with a brush in its mouth to paint the nibbled stems?
Young thorn trees can be pruned open at the bottom to encourage the plant to grow out higher up. In the veld, antelopes prune these trees from below. Thorn trees should therefore be kept in check by pruning when young. Where branches cross, wind can cause damage and therefore these branches must be pruned judiciously.
Deciduous and soft herbaceous shrubs
Deciduous shrubs that bloom in winter or early spring on the previous year's growth should only be pruned after they have flowered. These include plants such as the misty plume bush (Tetradenia riparia) which in winter form their soft pink, light purple to white plumes. These shrubs can be pruned directly after flowering. See Pelargoniums and Hydrangeas below.
Tetradenia riparia | Misty plume bush
Proteas, pincushions and conebushes
The majority of species do not need to be pruned. Sometimes a little pruning is necessary. Old flower heads and broken branches can be removed, or just to keep the plant neat, the branch tips can be topped to encourage branch division, thereby creating a more compact shape. If you prune it too low it will never grow out again. Resprouting species, such as the King Protea (Protea cynaroides), are an exception and will emerge again after severe pruning.
When planting new young proteas, you can prune or pinch off their first early flower heads at the beginning. This will encourage branching and the plant does not have to waste energy on flowers in its young stage. Once the plant is the desired height and reaches its mature shape you can leave it to bloom and enjoy the flowers.
Pruning of Ericas
Ericas can be lightly pruned and cut back after flowering. Pruning encourages branching resulting in a more compact shrub that will flower better next season. Remember that they only need to be lightly pruned.
Pruning of Pelargoniums
Fast-growing cultivars and species such as Pelargonium inquinans, P. zonale, P. denticulatum and P. scabrum should preferably be pruned back at least a third to half of the plant. The growth tips of smaller Pelargonium species can also be pinched off to encourage a better compact shape. The Pelargonium cuttings also grow so easily, so remember to share with a neighbour or friend instead of just throwing them away.
Indigenous shrubs that can be pruned during the winter (July-August)
The following fast-growing shrubs can be pruned back during the winters.
- Geelblombos (Phymaspermum acerosum),
- Wild phlox (Jamesbrittenia grandiflora)
- Coulter-bush (Hymenolepis crithmifolia)
- Jêmbekkie (Ruttya fruticosa)
- Red Ruspolia (Ruspolia hypocrateriformis)
- Fence aloe (Aloiampelos tenuior)
- Dolomite sage (Salvia dolomitica), and Wild giant sage (Salvia disermas)
- Bush violet (Tinnea barbata)
- Plumbago (Plumbago auriculata)
- Cape honeysuckle (Tecoma capensis)
- Forest bells (Mackaya bella)
- Pink mist bush (Syncolostemon obermeyerae)
- Spur flowers (Plectranthus fruticosus, Plectranthus saccatus), Plectranthus ecklonii, Plectranthus zuluensis)
- Pink sage bush (Ocimum labiatum)
- Ribbon bush (Hypoestis aristata)
- Lion’s ear (Leonotis spp.)
- Long-armed sage (Syncolostemon spp.)
- Purple Dissotis (Dissotis princeps)
- River star (Gomphostigma virgatum)
Tecoma capensis | Cape honeysuckle
The perennials listed below can be severely pruned after flowering during the winter. Spurflowers (Plectranthus spp.) can be pruned in late autumn when they have finished flowering. They will sprout out again in the spring.
- Riverbell (Phygelius spp.)
- Wild rosemary (Eriocephalus spp.)
- Mpumalanga Sagebush (Syncolostemon transvaalensis)
- Dwarf Thunbergia (Thunbergia natalensis)
- Rock sage (Aeollanthus spp.)
- Spoorsaie (Plectranthus spp.)
- Rock sage (Thorncroftia spp.)
- Aambeibossie (Aerva leucura)
- Creeping foxglove (Asystasia gangetica)
- Cat herb (Ballota africana)
- Bush violet (Barleria obtusa) and small bush violet (Barleria repens)
- Carnation (Dianthus spp.)
- Pink wild tibouchina (Dissotis canescens)
Plectranthus | Spurflower
Do these plants really need to be pruned?
This is never necessary in the majority of cases. Bulbs that are not evergreen can still be pruned to improve their appearance. Some larger Watsonias and Gladioli’s leaves dry out and then look unsightly. Prune only when the leaves have dried as the green leaves are still used to draw solar energy that is trapped in their bulbs.
Succulents also require virtually no pruning. Once the fast-growing, mass-flowering vygies (Lampranthus spp.) have finished flowering, their old fruit capsules and dead parts can be cut out in the summer or autumn season.
Roses want to be pruned for optimal flowering. Again, do not worry about making mistakes. The best time to prune is in July and August. Garden roses can be pruned back two thirds or more. Leave only a few short strong shoots from which the plant can sprout. Stem roses' crowns can also be pruned back by two-thirds, cutting out the older branches and leaving the young vigorous shoots from which it will sprout out again. Climbing roses only need to be lightly pruned right throughout the year. To make the roses appear neater, the dead flowers can be cut out regularly.
Hydrangeas do not need to be pruned hard. Only prune the flowering branches back to two buds. In this way, the plant is constantly renewed. The young shoots will produce flowers again and the pruning process can be repeated annually.
Fruit trees are pruned to improve fruit-bearing but not all fruits need pruning, for example, citrus and many other subtropical fruit trees. Only dead or diseased wood can be removed here.
Vines can be pruned back more drastically to a few shoots near its main stem. These shoots will again emerge rapidly in spring. Prune when all the leaves have fallen.
Most need pruning. There are two ways and the most common is the cup shape. Young trees need to be pruned more drastically to encourage firm frame-branches in a cup shape. The cup shape ensures that sunlight reaches most parts of the tree to lead to better fruit-bearing, and fruit can be harvested more easily. Fruit trees that benefit from cup form include apples, apricots, pears, peaches, plums and fig trees. The central leader method leaves the main branch, but side branches are left to form at different heights along the main stem, where the fruit is harvested. This is an easier pruning method.
Tap the article for more information on pruning stone fruit trees.
Climbing plants are very fast growers and often need to be kept in check with some secateurs. They can be pruned back during winter but also when necessary during other times of the year.
FORMAL FENCE AND SHAPE PRUNING
Formal pruning includes fencing and where plants are given all sorts of standard shapes. Although it is an unnatural process, there are many plants that respond very well to this type of pruning.
A fence can be either formal or informal. In the case of a formal fence, it is often necessary to cut it back from time to time to keep it in the desired shape. We have many indigenous plants are very well adapted to pruning, especially a few plants from the Eastern Cape and the bushveld. Shrubs with thorns are also suitable as a security fence, for instance, the dense kei apple (Dovyalis caffra) is virtually impenetrable. Spekboom (Portulacaria affra) makes a long-lasting drought-resistant fence that requires little attention other than maintaining its shape.
If you want to grow a fence, initially plant fairly densely and top the plants at an early age to ensure branch division. Later, when the fence starts to take shape, it must, from time to time, be pruned to be kept in shape. Some fences require very little pruning, for example, a Kranz aloe fence (Aloe arborescens).
Try the native shrubs below as hedge plants.
- Kei apple (Dovyalis caffra)
- Turkey berry (Canthium inerme)
- Climbing num-num (Carissa edulis)
- Big num-num or Amatungula (Carissa macrocarpa)
- Nata plum (Carissa haematocarpa)
- Cape box thorn (Lycium ferocissimum)
- Hedge spikethorn (Maytenus polyacantha),
Num num | Carissa spp.
- Confetti bushes (Coleonema album, Coleonema pulchellum)
- Sunbird bush (Metarungia longistrobus)
- Cape honeysuckle (Tecoma capensis)
- Plumbago (Plumbago capensis)
- Mickey Mouse bush (Ochna serrulata)
- Spekboom (Portulacaria affra)
- Poison star-apple (Diospyros dicrophylla)
- Bladder-nut (Diospyros whyteana)
- Hard-leaved monkey plum (Diospyros scabrida)
- Puzzle bush (Ehretia rigida)
- Bluebush (Diospyros lycioides)
- Fire-sticks (Diospyros austro-africana)
- Wild pride of India (Galpinia transvaalica)
- Bietou (Osteospermum monilifera)
- Scrambling fig (Ficus burtt-davyi)
- Kranz aloe (Aloe arborescens)
Pink confetti bush | Coleonema pulchellum
HOW DO I PRUNE?
Keep the pruning process as simple as possible. The stems consist of nodes and internodes. The internode is the long stem portion located between the leaves, and the node is located opposite the leaf axil. It is at the node where the plant's growth eye or axillary bud sits and from which it sprouts. Prune with sharp pruning shears just above the buds. It's not going to make a difference at what angle you cut. In addition, the plant will sprout quickly during the spring at the upper axillary buds.
Pruning tools include pruning shears and hand saws. Use good quality secateurs and make sure the blades are sharp. The Stanleyimported saws are extremely efficient and once you get used to them you will have a hard time sawing with a different type. Be careful not to prune or saw your fingers. Do not be in a hurry when pruning as this is how you can prevent accidents.
What should I do with the prunings?
The off-cuts come from your soil and are therefore valuable, slow-release plant nutrients. Recycle them by using them again. The prunings can be chopped up into short pieces with a mobile woodchipper and used again as an organic coating. It suppresses weed growth and protects the soil. In the past, we have greatly impoverished our soil by sweeping all leaves and organic matter on a heap and driving it off.
Branches can also be buried shallow. Eventually, the bacteria, fungi and insects will break down the wood. Use and recycle all organic materials, kitchen waste and make your own compost. The coarsely chopped pieces of branches can also be used on the compost heap. It does break down slower than other materials but eventually, it is converted to compost. Larger tree branches can also be cut into smaller pieces and used as for braai wood. The ash can then be added to the compost or in the garden. The stumps can even be left in beds. It is also a slow-release food source for surrounding plants.