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What Is Root Pruning? A How To Guide


If you’re a garden enthusiast, you probably already know what a savior root pruning is, but if you’re a gardening amateur, you might want to learn about this amazing technique.

Established plants and trees growing in the ground for a while have roots that extend far beyond their branches or drip line. While these branches anchor and support a plant, most of the feeder roots that bring in food and nutrients, grow off the main distance from the plant itself.

Root pruning is the process of cutting through the roots located at the drip line of an established plant or tree to dig and transplant it. This process is done to encourage the growth of feeder roots along with the root ball that will be transplanted with the tree. A root ball with numerous feeder roots is quite helpful in acclimatizing a tree or plant to its new spot.

Why Root Prune?

Here are a few cases in which root pruning can help.

To Maintain Dwarf Trees

Many times, root pruning is used to maintain dwarfed size plants and trees – that are simply slow growers. When a dwarfed tree starts growing more than its desired height, root pruning helps shock its roots temporarily by diverting its energy towards growing new roots.

To Encourage Flowering

Root pruning also encourages the flowering of fruit trees and slowly blooming vines, such as wisteria. In this situation, a plant believes it’s under attack, and it sets flowers and seeds to strengthen its defense.

To Help Plant Growth

Root pruning can also be very helpful when potted plants outgrow their containers, but you don’t want to move them to a larger one. Trimming back a plant’s roots and repotting it can help keep its growth in check. This is usually done to control the growth of indoor trees and plants.

To Save a Plant’s Life

When a plant gets root-bound due to its roots outgrowing its container, its health begins to deteriorate. Root-bound plants have a compact rootball that strangles that plant, keeping it from receiving water, air circulation, and proper nutrients. In such cases, the plant can be saved via root pruning.

How To Root Prune A Tree, Plant, Or Shrub

In simple terms, root pruning involves severing the roots of a plant or tree all the way around their circumference at the drip line using a sharp spade. Since this process can be a little challenging, it’s usually preferable to get it done via an expert. However, if you’re planning to do it by yourself, here are some steps to follow:

Step 1: Put Together Your Supplies and Tools

Start by gathering all your tools and supplies for the operation. It is very important because you can’t expect yourself to be stuck in the middle of a delicate procedure, covered in dirt, realizing that you need a certain tool.

Here is a list of tools you’ll need:

  • Pruning saw or serrated knife
  • Scissors
  • Potting mix
  • Perlite
  • Bucket
  • Hand trowel
  • Gardening gloves

Step 2: Cut Off the Roots Growing Out of the Pot

Once you’ve arranged your tools, cut off the roots emanating from the drainage hole, as doing this will make it much easier for you to pull the plant out of its pot.

Step 3: Pull the Plant Out of the Pot

This step may require two people or a bit of extra muscle strength, depending on the plant’s size. You’ll want to display your strength but remain gentle at the same time to keep the roots from ripping.

If you’re dealing with a big plant, lay it on its side to get a better grip. In case your plant’s in a plastic pot, apply pressure around the pot to loosen the rootball, enabling you to pull the plant out. Lastly, if your plant is in a ceramic or terracotta plant, use a long serrated knife to scrape around the edges to loosen up the soil.

Step 4: Loosen Up the Soil and Roots

Once you’ve pulled the plant out of the pot, make sure to loosen up and remove as much soil as possible. Not all plants will have soil in the rootball due to their crammed roots. However, if yours does, then make sure to loosen it up with your fingers or by gently tapping the back of your knife on the rootball.

Step 5: Prune the Bottom Roots

Use your saw or serrated knife to slice off the 1/2 to 1″ off the bottom of the rootball. If you’re conducting root pruning to maintain a certain height of your plant or tree, cut off even more of the rootball. However, remember not to chop off more than 1/3 of its root mass.

Step 6: Prune the Side Roots

Once you’re done pruning the bottom roots, it’s time to slice off the side roots around the rootball. Be very careful during this process, ensuring that you stay clear of tap roots. In case you do find taproots during pruning and find it challenging to cut around it using a knife, switch to scissors.

Step 7: Loosen Up Soil and Roots Again

Once you’ve pruned a good enough portion of your plant’s or tree’s roots, try to loosen up even more soil around the roots. This is quite beneficial for your plants as it helps get rid of soil saturated with excess mineral salts and depleted nutrients.

Step 8: Mix Soil and Perlite

Mix your plant or tree’s specific soil with perlite before repotting your pruned plant. Perlite is often a good option because it adds draining to the soil, which is important for plant health.

Step 9: Repot Your Plant

Once you’ve pruned the bottom and sides of your plant, there will be more than enough space for the pruned roots to grow back into the old pot. Allocate a fresh layer of potting mix at the bottom of a pot before placing your plant in it.

Step 10: Water Your Plant

As soon as your plant has been repotted, give it a good ol’ drizzle of water.

Step 11: Let Your Plant Rest

Once your plant or tree has been root pruned and watered, it’s time to let it rest.

The Bottom Line

Plants and trees often need major interventions to grow in a specific way, and root pruning is just the way to do it. We hope that our guide helps you conduct root pruning effectively to ensure that your plants remain healthy and happy.