by Erin Marissa Russell
All gardeners should learn to identify and fix rootbound plants as well as how to prevent it from happening. We’ve created this guide to equip you with the knowledge to diagnose a rootbound plant by sight, keep your plants from becoming rootbound in the first place,and treat rootbinding when it does occur. Not only will you be able to put your newfound expertise to work in your own garden—it’ll come in handy when you’re shopping for plants as well.
Often, some of the plants you’ll find in the garden center or nursery are already rootbound at the time of purchase. That’s because storebought plants have sometimes been housed in their containers for a year or more by the time they’re purchased. With the insight you’ll gain from this article, you can avoid selecting rootbound specimens when you’re choosing which plants to bring home with you. If all the plants available are rootbound, you’ll know just what to do to solve the problem once you get your gardening center haul home.
What does it mean for a plant to be rootbound?
Rootbound plants, sometimes called potbound plants, are basically plants that needed repotting long ago. Lacking the space to stretch out, the roots of a rootbound plant are congested and overgrown, stuffed tightly into the container. Instead of the root system spreading out like the branches of a tree, with plenty of space between the individual tendrils, a rootbound plant keeps its roots clumped together into a dense tangle. Acutely rootbound plants may have a root ball that takes the shape of the container, and some may have entirely replaced the soil of the pot with their densely coiled root.
What does a rootbound plant look like?
If you slide a rootbound plant out of its container, the roots and soil tend to come out in one solid wad—a crowded maze of roots that stays bunched together. In the case of severely rootbound plants, you may even see the roots snaking out the pot’s drainage holes, or the roots might have crept back up the container walls and be visible on the surface of the soil.
How can you tell if a plant is rootbound?
It can be difficult to diagnose a plant as rootbound without pulling it out of the container, because a rootbound plant can display the same visual symptoms as a plant that hasn’t been receiving enough water. These signals include stunted growth, quick wilting, and yellowing or brown leaves (especially toward the base of the plant). In severe cases, the crowded roots may cause a container to be misshapen or cracked.
When you’re selecting plants, shrubs, or trees at the garden center, check the underside of the pot to make sure roots aren’t visible poking through the drainage holes. You can also gently slide the plant up and out of the pot to inspect the root system and avoid bringing home a rootbound plant. The nursery staff won’t mind you checking plants for rootbinding, as long as you do it carefully and don’t cause damage. Any wrapping of roots around the sides of the container whatsoever means rootbinding has occurred, though if plenty of soil is visible, the plant may only be slightly rootbound.
What happens when a plant is rootbound?
If you don’t know otherwise, you might think a rootbound plant is a good choice because it’s developed such an extensive root system. After all, a plant’s network of roots help it draw water and nutrients from the soil to feed the plant and help it grow. But in fact, the opposite is the case. If the problem isn’t addressed, even when a rootbound plant is transplanted into a larger container or directly into the garden soil, its roots will stay clumped in a tight knot.
A rootbound plant won’t extend its roots into the free space surrounding the root ball, so it’ll miss out on a lot of the water and nutrients available to it in the soil. That’s why it’s important for a gardener to be able to identify rootbound plants on sight and know what to do to help them spread those roots out so the plant can grow healthy and strong.
Will rootbound plants die?
Without intervention from the gardener, a rootbound plant will receive less nutrition and hydration than plants that are not rootbound. In especially severe cases,bound roots can choke a plant, eventually resulting in its death. Either the stress or the starvation associated with rootbinding can kill a plant.
Can a rootbound plant recover?
With intervention, a rootbound plant can be saved. With the proper repotting technique and adequate hydration, it is possible for rootbound plants to recover. Keep reading to find out how to prune a rootbound plant’s roots and transplant it to a new container.
How do you get rootbound plants out of pots?
The appropriate technique is to use your thumb and forefinger to grasp the main stem and gently pull up while sliding the container downward. You only need to displace the plant by a couple of inches to check for the snarl of pale roots ringing the edge. In the case of plants that are truly stuck, you can slide a long gardening knife around the inside edge of the container to loosen things up so you can remove the plant. If even this doesn’t work, you may be left with no other option but to break the container to free the plant.
Healthy plants may have a few visible roots along the edges of the container, but you’ll also see plenty of soil. In addition to showing you that a plant’s overdue for transplanting, overgrown roots may be a symptom of getting insufficient nutrition or water while it developed, so you’ll want to avoid choosing rootbound plants whenever possible.
How do you repot a plant that is rootbound?
Once you’ve identified a rootbound plant, the next step is to move it into a new, roomier container. Not only will transplanting into a new home give a rootbound plant the space to stretch out and expand its root network—a fresh batch of potting soil provides the plant with some much-needed nutrition.
After removing the rootbound plant from its container, use your fingers to delicately untangle the roots and give them some breathing room. Loosening the root ball so the system branches out encourages the roots to keep expanding into new territory once they’re planted in their new home. Soaking the plant in water overnight can soften the roots and make them easier to disentangle.
If the roots are so densely clustered that they can’t be untangled by hand, you’ll need to break out the tools. Using a clean, sharp knife or gardening trowel, slice a few slits into the root ball. Cut a few incisions into the sides of the root ball, followed by a deep X shape in the bottom. This technique will give the roots the opening they need to break out of the tangle and into fresh soil. Don’t be concerned that cutting into the roots will damage the plant. On the contrary, some gardeners use this strategy every time they rehome a plant to spur the roots to keep broadening their range.
When you’re done cutting, add enough potting soil to the container that when you add the plant, the place where the stem and roots meet is about one inch from the top of the pot. Then place the plant on top of the soil, filling in the spaces around the roots with more potting mix. Water the plant deeply once it’s been repotted. If the soil settles to a lower level after the plant’s been watered, add more soil. Take special care to keep the plant adequately hydrated for a few weeks after transplanting so it won’t be stressed by the move. Be sure to use new soil when you repot a rootbound plant, as the soil that was in the container while the plant grew is sure to have been stripped of its nutrients.
How do you prune roots before transplanting?
You might choose to use root pruning instead of completely repotting a rootbound plant if no larger containers are available—or if their current home is a container you particularly like and you wish to keep the plant in it. Root pruning is also used on plants that are purposefully kept at a limited size, such as those in a terrarium and bonsai or containerized trees.
Use scissors, pruning shears, or a sharp gardening knife to cut around the edge and along the bottom of the root ball. You can cut away large and small roots, and don’t be afraid to be a little bit forceful. You won’t harm the plant, and it’ll be encouraged to spread its roots out and grow stronger. Once you’re done trimming, use a fork, stick, or pronged cultivator to loosen the root ball around its edges and at the bottom to give the roots some space to breathe.
While it’s common for plants at a nursery or in a home garden to be rootbound, as you’ve learned, the results can be disastrous. Luckily, the solution is simple and doesn’t ask much from the gardener when it comes to time, energy, or cost. With the strategies and knowledge you’ve gained from this article, you’re ready to identify rootbound plants, prevent your container plants from becoming rootbound, and troubleshoot rootbinding if it happens in your garden.
Want to learn more about rootbound plants?
Gardening Know How covers Root Bound Symptoms
Grow Organic covers Root Pruning for Container Plants
University of Florida covers Root Pruning Guidelines
The Spruce covers Caring Tips for Root Bound Plant
The Spruce covers How to Tell if Your Plant is Rootbound
The Spruce covers Loosening Rootball of Plants