Original post created in 2015 by Ronda Roemmelt and Leda Marritz, updated in 2026.

One of the questions we are frequently asked is, “How often do you root prune?” The short answer: not every tree needs it. Root pruning can be a valuable tool for preparing certain field-grown trees for transplanting, particularly when they need to be dug outside their ideal season or when a more concentrated root system is beneficial. But it takes time, can slow a tree’s above-ground growth, and simply isn’t necessary for every tree in the nursery.

So, should tree nurseries root prune? Sometimes. The better question is when root pruning makes sense — and what we’re trying to accomplish by doing it.

What Is Root Pruning?

Root pruning is just what it sounds like: cutting roots, much as we would cut branches, only using a tree spade, shovel, or trenching machine. When roots are severed ahead of transplanting, the tree can generate new roots near the cuts, concentrating more roots within the area that will eventually become the harvested root ball. Root pruning in advance of transplanting is an established nursery practice for helping develop a more compact root system before a tree is moved.

There are several reasons a nursery might choose to do it.

Preparing for an Off-Season Dig

Some trees might need to be dug in a less-than-preferable season. Oaks, for example, typically dig best while dormant. But let’s say those trees will not be needed until July. We may choose to root prune during dormancy, giving the trees time to regenerate roots before they are dug outside their optimal season.

That advance preparation can give nurseries greater flexibility during what would otherwise be a relatively short harvest window.

Concentrating Roots Within the Root Ball

A field-grown tree leaves a significant portion of its root system behind when it is harvested. Root pruning in advance encourages root development closer to the trunk and within the area that will later be dug.

Because a root-pruned tree may have a higher concentration of roots closer to the trunk, it may also be possible in some circumstances to harvest it with a more manageable root ball. That can be helpful on projects that cannot accommodate a larger ball size or large piece of equipment.

The important point is not simply “more roots.” It is more regenerated roots where they can ultimately be captured and moved with the tree.

Managing Growth

Root pruning can also slow the above-ground growth of a tree. Severing roots prompts the tree to devote resources to regenerating its root system, which can temporarily reduce increases in height and caliper.

That can be useful with fast-growing species such as Liriodendron (tulip poplar) and Prunus (cherries). But it is also one of the reasons we don’t root prune everything.

What about Fagus (beech) or Ginkgo? Slowing down an already slow-growing species can mean longer production times and fewer available trees.

Seeing Root Regeneration in Action

In one demonstration, we root pruned a red maple in early spring. We had actually prepared it for a demonstration on bare-rooting that was later rescheduled, but the preparation work gave us an excellent opportunity to see just how effectively the tree regenerated roots.

In the photo above, you can see the new fibrous roots that developed in just four months.

Will you just look at those gorgeous roots!

The example illustrates the basic purpose of advance root pruning: make the cuts first, allow time for roots to regenerate, and then harvest the tree with more of that regenerated root system contained within the root ball.

So Why Not Root Prune Every Tree?

If root pruning can help prepare trees for transplanting, why not simply root prune every tree in the nursery?

One reason is growth. As mentioned above, slowing a vigorous tree can sometimes be useful. Slowing an already slow-growing tree may not be.

Another simple (and honest) reason is time. Root pruning is time-consuming. Each year, nurseries have to decide which trees are most likely to benefit from the extra preparation and plan accordingly.

At our nursery, root-pruned trees are marked so we can track when the work was performed and follow their history. Advance root pruning can help expand the normal harvest window, but it requires knowing which trees may be needed well before they leave the ground.

And that may be the most important point of all: some trees need to be prepared months, and sometimes even longer, before they are transplanted.

If you know when a project will be installed, communicating with your nursery early can give them more options for preparing the trees appropriately. Find a nursery you trust and develop that relationship early; good planning before the tree ever leaves the nursery can make a meaningful difference once it reaches the project site.