Is it thinning or pruning? What’s the difference?

Thinning and pruning are two vital methods of garden maintenance that are distinct from one another. Thinning and pruning are often used interchangeably, but they are not the same. However, if you can execute both techniques properly, your plants will become healthier, live longer, and you’ll create the landscape of your dreams.

Thinning is a technique used to remove stems from a tree or another plant right down to their attachment points to promote healthy growth. Pruning is more precise and involves removing excess foliage such as dead, dying, and diseased branches.

Pruning improves the health of your plants by ridding them of dead leaves, stalks, and branches that are either sucking up nutrients from or spreading diseases to your plant. Thinning is the same concept, but it’s also about ensuring that branches are at their healthiest the closer they are to the trunk. In addition, it ensures that the weight of a plant is correctly distributed and that every part of it is absorbing as much nutrition as possible.

The Difference Between Thinning and Pruning

While many people use the terms “thinning” and “pruning” interchangeably, they aren’t the same. In general, pruning is simply cutting branches away from a tree or shrub. Thinning, on the other hand, reduces the density of all branches in a tree. Thinning can even be performed on the roots of a tree. It is a process of “making space” for your plant or tree to grow.

Pruning is essentially the same, but pruning refers to a method done by hand, where you cut off dead or dying branches and excess foliage but doesn’t interfere with the growth of healthy limbs.

Pruning removes dead dying branches and helps branches grow in a specific direction to make your plants or trees more aesthetically pleasing. In addition, when we prune plants in the winter, it encourages new growth without damaging them because they are dormant. Spring pruning encourages healthy new shoots, and summer pruning helps to reduce the number of nutrients required for the plant to survive. 

Pruning during the fall is not a good idea and will encourage disease due to the increased fungal spore count in the air at that time of year.

Thinning allows sunlight to penetrate the interior branches of a tree or plant. As a result, the diameter of the branches should decrease as they get closer to the trunk, which makes the branches stronger and improves their overall health. 

Thinning also decreases the incidence of foliage diseases due to improved airflow and additional exposure to sunlight.

It is also worth distinguishing pruning and thinning from trimming. The latter is a purely aesthetic gardening technique that only focuses on the outside/canopy of a plant/tree/shrub.

Why You Should Prune Your Plants

Think of it this way, dead leaves, dead stalk, branches, or any excess foliage on a tree or a plant is leeching off your plant. It’s taking up energy, offering nothing back, and is susceptible to diseases, which will inevitably spread to the rest of your plants. Think of pruning as if it was amputating a festering limb.

Think of thinning, however, as the opposite. You’re looking to promote healthy growth by cutting branches right down to their attachment points. Doing this decreases the weight that’s being held by other bigger branches that are carrying it. And these newer, smaller, weaker branches are also taking up a lot of space, limiting airflow throughout the tree and stopping sunlight from reaching the branches below them.

Your plant has so many branches that it just simply can’t carry them all. The healthy ones that can survive without much extra care should be preserved and the focus of your plant’s energy. But to let the best branches thrive, you have to rid your plant of the foliage weighing it down, the deadweight. 

How To Prune Your Plants

When and what to prune depends entirely on the plant and the climate you live in, but flowering and fruiting plants typically preferred to be pruned in late winter or early spring. Plants that bloom in the spring will start setting their new buds when old flowers have fallen, so you need to prune them before those new buds come in. Doing this will keep your plants vigorous and looking their best by the time summer rolls around.

Fortunately, pruning at the wrong time is rarely fatal, but you must familiarize yourself with your plants’ cycles so that you get more flowers or fruit. Fruit trees and berry plants should be pruned when they are dormant (in the winter). Most perennial plants (expected to live longer than two years) require cutting back or deadheading before or after the growing season. 

Once you’re familiar with your plant’s growing cycle, start by inspecting your plant. Check where it needs pruning and identify which branches need to be removed based on their health, shape, or growth pattern. Then remove the unwanted branches from your plant and make heading cuts with loppers or a hacksaw.

How To Thin Your Plants

Removing branches or thinning provides more room for other branches to grow, so it’s more about the long-term health of your plant and is a technique that’s primarily used for trees simply because of their extended lifespans.

Before thinning, your plant’s canopy will be very dense towards the outer edges, which means it’s probably casting shade over parts of the tree that you want to grow. Your objective is to remove the small branches from your plant’s middle and outside portions (Not from the interior!). So, thinning should not affect the overall size and shape of the plant. And you’re looking to have an even distribution of smaller branches across the main branches, not for branches to be collected into little groups. 

You want to start by removing the branches from the edge of the canopy and take caution not to create the “lions tailing” effect, which is when the majority of the plant’s interior branches have been removed, leaving behind only terminal leaves. It also puts all of the foliage weight on the end of the branches (which are thinner, less healthy, and weaker) and could ultimately lead to breakage.

You should not remove any more than 15-25% of a plant’s live foliage at once and, for mature, more established plants, 5-10% is more than enough.

Conclusion

So if you’re looking to get your garden looking its best, then thinning and pruning are the greatest weapons in your arsenal. And if your plants aren’t producing as many flowers, if their leaves and branches aren’t looking healthy, they aren’t living up to their full potential, and you’ll never get to truly appreciate these beautiful little green creatures for the works of art that they are.

Trimming and pruning can be complicated, and, particularly with trees, you should always put safety first and consult with professionals before undertaking any large projects. And once you’ve started to figure out exactly how your plants react to changes of season, you’ll see your garden transform into the small slice of paradise that you’ve always wanted.

Sources

What’s the difference between tree trimming and pruning? | Yellow Pages

Tree Trimming vs. Pruning: What’s the Difference? | Reliable Tree Care

Pruning Versus Trimming: What’s the Difference? | The Complete Pruning Guide

Thinning the canopy | Landscape Plants

What’s the Difference Between Thinning & Pruning? | Connect2Local

How to Prune Trees and Plants | The Spruce

How to thin plants to help garden grow | SF Gate