Pruning is the selective removal of plant parts, including branches, buds, leaves, blooms and roots. Pruning can involve the removal of living, dying or dead plant parts. Pruning applies to both soft-tissue (herbaceous) plants and woody plants (trees, shrubs, etc.).
Understanding the goals of pruning is very important. People often prune plants without knowing why they need to prune the plants in the first place. This leads to mistakes and may waste time and resources on pruning that may not be necessary or pruning too late in the plant’s life. Understanding the goals of pruning can also save much time and resources in the long term. For example, proactive pruning to train a younger plant can save much time and hassle pruning later, prolong the lifespan of the plant and improve the appearance of the plant.
Pruning is an art and science of many levels of sophistication. Basic pruning techniques can be learned very quickly—others are more complicated and require ongoing training and extensive hands-on experience. There is no “one way” of pruning plants. Proper pruning practices depend on many factors, including the type and health of the plant and the goal of the pruning.
Starting with small herbaceous plants is a good way to practice pruning for starters. Fortunately, many of these plants are used in indoors and make a great foundation for learning how to prune properly.
The goals of pruning can vary; the following are the primary reasons plants are pruned indoors:
- Maintaining Plant Health – Removal of dead, dying or infested plant parts and thinning out a canopy to allow more air flow and/or light penetration.
- Training a Plant: To promote/create a certain shape, height or width of a plant (lateral branching, bushy/compact form, etc.)
- Improving Quality of Foliage and Stems
- Restricting Growth/Hazards: Removal of plant parts that pose a safety hazard or may grow into a structure or object or otherwise interfere.
Maintaining Plant Health
Judicious pruning of a plant can help improve the health of a plant. Plant parts infested with a disease or a pest may be removed to reduce or eliminate the pest/disease.
Dead or dying plant parts are not only unattractive but also harmful to the plant as they can provide food and shelter to harmful pests and diseases that could spread to living plant parts.
Indoor plants can sometimes get over-grown which blocks light to plant parts and reduces air flow. Ficus trees planted near large windows will often develop a thick, healthy canopy on the window side where light is highest. This creates a tree that is very full on one side yet quite thin on the other side. The reason the tree thins on one side is due to all the light being blocked from the thick side facing the light. One way to help create a fuller tree is to thin out branches on the thick side to allow more light to penetrate the darker side of the tree, creating a fuller, more balanced tree. Branches that intersect (hit one another) are also removed to prevent wounding and grafting together.
Thinning a canopy will help light penetrate both sides of the tree, leading to a fuller-looking tree. The thinning will also allow better air flow.
Under-planting Pothos beds are notorious for over-growing, causing a thick mass of vines (some of which are woody). This creates a tangled mess that is very difficult to clean and manage over time. It also reduces air flow and creates the perfect environment for pests (such as mealybug) to proliferate and multiply by the hundreds of thousands, in addition to infectious diseases and long, spindly growth due to low light created from the Pothos leaves canopy. Thinning these Pothos beds allows better air flow and light penetration, creating healthier, pest-free environments.
To Train a Plant
Bonsai is an example of a very intense pruning process that trains a plant to grow a very specific size and shape. Although Bonsai is rarely practiced in interiorscapes, training a plant via pruning is a very important yet over-looked pruning practice for interiorscapes.
A common example of training a plant in interiors would be large woody plants such as Ficus trees. Ficus trees can be pruned judiciously to encourage lateral (sideways) branching to create a broader, fuller looking tree. Left untrained, a Ficus tree will often develop many vertical branches growing straight up. This creates a very tall, disproportionately thin and unattractive tree. Improper pruning practices can make this even worse. In general, plants that are fuller, healthier and more attractive.
Quality of Foliage and Stems
Ornamental plants are displayed in buildings for their ornamental appeal. Roses, for example, are pruned heavily to encourage abundant blooming. Foliage plants are grown almost exclusively for their foliage (leaves). Only a handful are grown for their blooms as well their foliage (Spathiphyllum is the most common). A variety of plants bloom but these blooms (or their buds) are removed to encourage strong foliage development that is otherwise sacrificed somewhat to bloom development and seed production. Aglaonema blooms are removed because they have very little aesthetic appeal. Removing them allows the plant to dedicate more resources and energy to more important functions, such as new leaf growth.
Another example is with Ficus trees. In many situations, two branches will emerge from one. Often the smaller or less desirable branch is removed to allow the other branch to develop strong and healthy—this ensures a tree with structural stability.
Pruning out older growth can also encourage newer, more lush and vibrant growth. Schefflera, Pothos, Aglaonema, and Dracaenas are pruned to encourage newer and more vibrant growth (plant rejuvenation). Additionally it encourages a more compact, well-branched plant.
Plants in buildings can easily become over-grown (in some cases because proactive pruning was never practiced). Regardless of the cause, plants can grow to become too large for a particular space, requiring their growth to be pruned out. Trees in interiors may grow too tall and threaten to hit a ceiling, wall or other structure or object. In some instances, you may just want a smaller, more compact specimen. Branches are pruned out accordingly to reduce the overall height and/or width so its growth no longer interferes.
Larger plants, especially woody trees, can pose a serious hazard if branches are at risk of falling off a tree or having a large tree tip over on its side. In these situations, the plant is pruned accordingly to remove branches that pose a safety hazard. Dead or dying growth is weaker and should always be removed, regardless of whether or not it is a safety hazard.
Do you have any plant pruning questions? Share them below in the comments!