Girdling Roots

Girdling Roots

I killed a fiddle leaf fig last year. Well, technically it died from root rot, but when I finally pulled it out of the pot, I found something that made me feel even worse about the whole situation. The roots had wrapped around themselves so tightly at the base of the trunk that they looked like they were strangling the plant. I had no idea that roots could do that, or that it was even a problem I should have been watching for.

That was my introduction to girdling roots, and honestly, I wish someone had told me about this sooner. It turns out this is a pretty common issue with potted plants, and it happens way more often than you’d think.

Roots choking the stem

So what exactly are girdling roots? The term sounds dramatic, but it’s pretty literal. These are roots that grow in a circular pattern around the base of the plant’s stem or trunk instead of spreading outward like they should. Over time, as both the roots and the stem grow thicker, the roots start to compress the stem. It’s like wearing a belt that gets tighter every year.

The first time I actually noticed this problem was on a rubber plant I bought from a local nursery. I was repotting it a few months after bringing it home, and when I knocked it out of the pot, I could see these thick roots wrapped around the base in tight loops. Some of them had already started to dig into the stem tissue.

From what I’ve learned, this happens most often with plants that have been in containers for too long. The roots hit the edge of the pot, and instead of having anywhere else to go, they just keep growing in circles. Nurseries sometimes contribute to this problem by keeping plants in small pots longer than they should. I’ve also read that it can start when a plant is initially potted incorrectly, with roots already crossing over each other.

According to research from North Carolina State University Extension, girdling roots essentially cut off the plant’s vascular system. The outer part of a woody stem contains the phloem, which is responsible for moving sugars and nutrients from the leaves down to the roots. When a root wraps around the stem and squeezes it, that flow gets restricted or completely blocked (North Carolina State University Extension).

The tricky part about girdling roots is that you often don’t notice them until the damage is already done. The roots are hidden under the soil, so unless you’re actively looking for them, they can strangle a plant for months or even years before you see symptoms above ground. By the time I saw what was happening to my fiddle leaf fig, it was already in bad shape.

Signs that your plant might have girdling roots include stunted growth, leaves that are smaller than they used to be, yellowing foliage on one side of the plant, or branches that die back for no clear reason. Sometimes the stem will look flattened or indented where a root is pressing into it. I’ve also noticed that plants with this problem seem to struggle more during dry periods, probably because their water transport system is being squeezed.

Pruning girdling roots

When I discovered those roots on my rubber plant, my first instinct was to leave them alone. Cutting roots seemed scary, like I might kill the plant faster than the girdling would. But after digging through some university horticulture sites and talking to people on a houseplant forum, I learned that removing girdling roots is actually the right move, and most plants handle it surprisingly well.

The best time to deal with girdling roots is during repotting, when you already have the plant out of its pot. I usually repot in spring or early summer when plants are actively growing, which gives them the best chance to recover from any root pruning.

Here is how I approach it now. First, I remove as much soil as I can from around the base of the plant so I can actually see what’s going on with the roots. Sometimes I use a chopstick or an old fork to gently work the soil loose without damaging the roots more than necessary. Once I can see the root structure clearly, I look for any roots that are circling the stem or crossing over the top of the root ball.

For small girdling roots (thinner than a pencil), I just cut them off completely using clean pruning shears. I make the cut as close to where the root starts circling as possible. If the root is already embedded in the stem, I carefully cut it away, even if it means taking a small amount of bark with it. This sounds brutal, but leaving the root in place causes more damage over time.

Larger girdling roots are trickier. If a major root is circling but hasn’t dug into the stem yet, I sometimes try to redirect it instead of removing it entirely. I’ll make a shallow cut along the inside curve of the root to interrupt its growth pattern, then position it so it points outward when I repot. The University of Minnesota Extension recommends this approach for larger roots because removing too much of the root system at once can stress the plant (University of Minnesota Extension).

I won’t lie, the first time I pruned girdling roots, I was nervous the whole time. I cut away maybe three or four circling roots from that rubber plant, and it looked rough for a few weeks afterward. But it bounced back, and now it’s one of my healthiest plants.

One thing I learned the hard way is to always use sharp, clean tools. Dull shears crush the roots instead of making clean cuts, which increases the chance of rot setting in. I wipe my pruning shears with rubbing alcohol before I start, especially if I’m working on multiple plants.

Above: A close up look at the symptoms.

Repotting strategy

After you’ve dealt with the girdling roots, how you repot makes a huge difference in whether the problem comes back. I used to just stick plants in a pot with fresh soil and call it done, but I’ve gotten more careful about it since learning about this issue.

The first thing is pot size. I know a lot of people say to go up two or three pot sizes when repotting, but I’ve found that causes more problems than it solves. When there’s too much soil around the roots, it stays wet longer, which can lead to rot. Now I only go up one size, maybe two inches wider in diameter than the old pot. This gives the roots room to spread outward without drowning them in excess soil.

I also pay attention to the depth. A common mistake, and one I definitely made with that fiddle leaf fig, is planting too deep. When you bury the root flare (that’s the point where the trunk widens out into roots), you’re essentially asking for trouble. The buried roots can start circling under the soil surface where you can’t see them. These days, I make sure the top of the root ball sits at the same level it was before, or even slightly higher. Some gardeners call this “planting proud.”

The type of soil matters too. I use a mix that drains well but still holds some moisture. For most of my tropicals, that means mixing regular potting soil with perlite and a bit of orchid bark. The perlite keeps it from compacting, which encourages roots to grow outward instead of circling. When soil gets compacted and heavy, roots seem to take the path of least resistance, which often means going in circles.

When I’m actually putting the plant in its new pot, I spread the roots out as much as I can. If they’re really tangled or circling, I’ll gently tease them apart with my fingers or even make a few vertical cuts along the outside of the root ball. This is called scarification, and it encourages new root growth that heads outward instead of continuing the circular pattern. The Missouri Botanical Garden recommends this technique especially for plants that have been rootbound for a while (Missouri Botanical Garden).

After repotting, I water thoroughly to settle the soil, but then I’m careful not to overwater while the plant is recovering. The root system has been disturbed, so it can’t take up water as efficiently for a few weeks. I’ve rotted out more than one plant by being too enthusiastic with the watering can right after repotting.

Prevention

Honestly, the best strategy is to not let girdling roots develop in the first place. I’ve gotten better at this with practice, though I still mess up sometimes.

The main thing is staying on top of repotting. I know it’s easy to let plants sit in the same pot for years, especially if they still look okay. I’m guilty of this with my pothos collection. But checking your plants every year or two to see if they need more room makes a huge difference. I usually look for roots growing out of the drainage holes or circling around the inside edge when I tip the pot over. Either of those signs means it’s time to repot.

When I buy new plants from a nursery, I almost always repot them within a few weeks, even if they seem fine. Nurseries often keep plants in small pots longer than ideal because it’s cheaper and easier to manage. I’ve lost count of how many times I’ve bought what looked like a healthy plant, only to find a mass of circling roots when I knocked it out of the nursery pot. Now I just assume every new plant needs repotting and plan accordingly.

If you’re propagating plants or starting them from seed, how you pot them up initially matters. I used to just shove a cutting into whatever pot I had lying around without thinking about it. Now I’m more careful to spread the roots out when I pot up a rooted cutting, and I avoid using pots that are way too big, which seems counterintuitive but actually helps. When roots have a specific space to fill, they seem to do better than when they’re swimming in too much soil.

For outdoor container plants, I’ve learned that fabric pots can help prevent girdling. The roots hit the fabric and essentially air-prune themselves instead of circling. I haven’t tried fabric pots indoors yet because I’m worried about the mess, but it’s something I’ve been considering for my larger floor plants.

Another prevention tip I picked up from a local gardening group is to avoid piling mulch or soil up against the stem of the plant. This is more of an issue with outdoor trees, but it applies to houseplants too. When you add fresh soil during repotting, keep it level with where it was before. Don’t create a little mountain around the stem. That buried stem tissue can develop adventitious roots that may circle under the soil.

Above: The tools you need to fix this.

Tree health impact

I don’t have any outdoor trees in my current apartment, but I’ve been reading about girdling roots in landscape trees because the same principles apply, and the consequences are even more severe.

With trees, girdling roots can take years or even decades to kill the plant. The slow strangulation weakens the tree gradually. According to research from the University of Florida’s Environmental Horticulture Department, girdling roots are one of the leading causes of decline and death in landscape trees (University of Florida IFAS Extension). The tree might look fine for years, then suddenly decline rapidly once the damage reaches a critical point.

The vascular system in woody plants is everything. The xylem moves water and minerals up from the roots to the leaves. The phloem moves sugars produced during photosynthesis back down to feed the roots and the rest of the plant. When a girdling root compresses the stem, it’s like putting a tourniquet on that system. At first, the plant can compensate. It might develop extra vascular tissue around the constriction, or other roots pick up the slack. But eventually, the damage becomes too much.

What really strikes me about girdling roots is how preventable the problem is, and how devastating it can be if ignored. A tree that could have lived for fifty or a hundred years might die in twenty because someone planted it too deep or didn’t notice circling roots in the nursery pot.

For houseplants, the timeline is faster but the principle is the same. That fiddle leaf fig I lost was probably dealing with girdling roots for months before I noticed anything wrong. By the time it started dropping leaves and showing dieback, the damage was already extensive. Even though I tried to save it by removing the girdling roots and repotting correctly, it was too late. The plant had been struggling for so long that it didn’t have the energy to recover.

I think about that plant sometimes when I’m repotting others. It was a stupid, avoidable mistake on my part. I should have checked the roots when I first bought it, or at least repotted it within the first year. Instead, I let it sit in the same pot for almost three years, and by then the roots had wrapped around the base of the trunk so many times that removing them meant cutting away most of the root system.

These days, I’m much more proactive. I check my plants regularly, I repot before things get desperate, and I’m not afraid to prune roots when necessary. It’s made a noticeable difference in how well my collection does overall.

Girdling roots are one of those problems that seem invisible until they’re not. They’re happening underground, out of sight, slowly choking the life out of a plant while everything above the soil looks normal. But once you know what to look for and how to deal with it, it becomes just another part of taking care of plants. Not fun, exactly, but manageable. And definitely worth the effort to keep your plants healthy for the long run.

References

North Carolina State University Extension. “Girdling Roots.” NC State Extension Publications.

University of Minnesota Extension. “Pruning Trees and Shrubs.” University of Minnesota Extension Yard and Garden.

Missouri Botanical Garden. “Container Gardening: Root Bound Plants.” Missouri Botanical Garden Gardening Help.

University of Florida IFAS Extension. “Girdling Roots.” Environmental Horticulture Department.