Bad Pruning Cuts Can Kill Actually Your Plants – Avoid These 3 Major Pruning Mistakes to Prevent Problems

Bad pruning cuts and other easy-to-avoid mistakes can seriously hurt plants. They can make plants more susceptible to diseases and pests, send them into shock during dangerous times of year, and even kill plants. That's why learning the proper pruning technique is so important if you want to grow strong, thriving shrubs, trees, and perennials.

Whether you're a brand new gardener and know nothing about pruning basics yet or you're an experienced gardener who needs a refresh, there are common pruning mistakes that any of us can make. That's why I've compiled a list of the worst pruning blunders to avoid.

These errors are easy to make, but luckily they're also easy to avoid. Read on for the most common kinds of pruning mistakes almost every gardener makes at some point in their life, then learn how to avoid them.

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Most Common Pruning Mistakes

Gardeners prune plants for a variety of reasons. Pruning can train a plant, keep it healthy, help it to flower or fruit, or keep the foliage and stems strong and attractive. In order to help pruning cuts heal over quickly, you have to prune at the right time and in the right way. But improper pruning can upset this healing process and cause undue stress on plants.

Sometimes there is little you can do to repair the damage over-pruning or improper pruning other than waiting for the bad “haircut” to grow out. However, in some cases, repairing bad pruning simply requires additional care. Let's take a look at the most common pruning mistakes and how to avoid them.

1. Not Pruning Enough

Not pruning plants at all tops the list of common pruning mistakes, but it's also the easiest one to avoid. Not pruning may be due to laziness or fear of ending up with botched cuts.

While pruning isn't necessary for every plant in your garden, ignoring this vital gardening task altogether can lead to problems with the plants that benefit from pruning every once in a while. It can lead to overgrown shrubs or trees that are too tall and end up overshadowing your garden or growing out of control.

The solution to this issue is to prune. Removing old, dead, and damaged branches will stimulate the plant to produce new wood. Never take out more than one-third of the canopy of a tree or the branches or height of a shrub in a single season.

If an overgrown bush or tree requires more trimming, like rejuvenation pruning, cut back another third the following year and then again the next year to totally revitalize the plant.

2. Pruning at the Wrong Time

The best time to prune plants varies. Generally, you want to prune plants during dormancy or in the opposite season from when they bloom. For example, prune late summer or fall-blooming plants in early spring and prune spring-blooming plants in fall.

Of course there are exceptions to this rule, especially for plants that bloom on old wood, like mophead hydrangeas. For plants that flower on old wood, the best time to prune is immediately after blooming. If you wait too long then they will set buds for the next year and when you prune, you will actually be cutting off next year's flowers.

The best time to prune trees is usually in winter or early spring. That’s because many trees go dormant or stop growing in winter. If you made a serious pruning mistake with timing and pruned a tree in summer or fall then you may have removed buds, flowers, or fruit.

The solution is to wait until winter and prune again using thinning cuts or reduction cuts. The former takes out an entire branch at its point of origin on the trunk, while the latter cuts a branch back to a lateral branch.

3. Making the Wrong Cuts

Making the wrong kinds of pruning cuts can cause major problems for your plants. Using dull or dirty tools is terrible for your plants. Jagged cuts and cuts made with improperly cleaned tools may let in common diseases that can kill your plants. Not cleaning your pruning tools before moving onto the next plant spread diseases from one plant to every plant your prune in your garden.

You should also cut branches at a 45° angle just above a node. Angle your pruners away from the bud to prevent damaging it. The bud is where new branches, leaves, or flowers form, so you want to keep these healthy and intact. Angling your cuts also promotes healing and neat, new growth.

The worst of the worst when it comes to bad pruning cuts is topping a tree. Reducing the size of a tree by cutting the top of its primary leader creates far more problems for the tree than it solves.

If you top a tree, you’ll find that it creates a variety of waterspouts or new vertical branches to replace the one removed. These compete for dominance and, as they do, compromise the structural integrity of the tree.

The solution is to choose a new leader yourself and offer it support. For conifers, tape a branch from just below the pruning wound so that it stands vertically. In time the branch will grow straight up naturally and serve as the leader. In deciduous trees, select one of the new leaders and cut back any competition.