Knowing when plants like peppers — including both sweet peppers and chilies — have become root bound or containerized is one of the more important gardening skills. It is also useful to know how to treat root binding, since it can affect whether one of your pepper plant lives or dies. The guide below can help you spot root bound plants by their symptoms and show you how to make them healthy.
Table of contents
What is a root bound plant?
Root bound plants can be described simply as plants that have outgrown their containers. If a plant’s root binding is severe, that means it outgrew its space a long time ago. When a plant is growing as it should, its root system will grow outward from the stem like the branches of a tree. The roots will run into the inner surface of the container and start growing downward and then up again when they come into contact with the bottom of the container. Some root tendrils might grow around in a circular pattern.
The roots will eventually take up all of the space inside the pot, so there won’t be much soil remaining. Without soil, the plant won’t be getting much of the nutrition it needs. It may also lack sufficient water and air. Root binding can also happen if a plant was potted in a container too small for it from the start. In that case, it won’t have to sit for a long time before it becomes root bound. You will also see the problem come up because nurseries may keep plants in their inventory for long periods before they get sold.
What are common symptoms of root bound plants?
Diagnosing root binding can be tricky because the symptoms overlap with other pepper plant problems conditions. Root bound plants may have issues with water and nutrition uptake, so the plant may appear to need more regular watering and fertilization.
The leaves may be yellow or brown or wilt easily. Sometimes the leaves will drop or grow curled and misshapen. Even if you give it water and fertilizer, a root bound plant may fail to absorb them. If you plant it in the ground without doing anything to fix it, the plant may continue to die slowly, since the roots will keep growing as they were and go on entangling themselves.
If the soil composition is very different from that of the potting medium, this may make matters worse, as the roots may fail to penetrate it and just keep growing around and around instead of outward.
What does a root bound plant look like?
In many cases, the roots of a root bound plant will be visible at the top of the container. You may also see them growing out of the drainage holes at the bottom. The roots can be anywhere from yellowish-white in color to brown. Sometimes you will have to remove the plant from its container to see whether it is root bound and to what extent.
Many plants will slide out easily if they are not overly bound. Because the roots are growing in circles and coiling around themselves within the container and the potting medium, the clump of roots will often retain the container’s shape when you remove it.
How do you get root bound plants out of pots?
Because root binding can cause other issues and be difficult to diagnose, you may have to remove some plants from their containers to know whether they are root bound. A root bound plant can affect its container. In some cases, you will be able to tell from the condition of the container. The force exerted by the expanding roots can crack or change the shape of some containers.
In extreme cases, the compacted mass of roots will make extraction difficult. For pots made of flexible plastic, you can try squeezing the pot to loosen the roots and separate them from the pot. If the container doesn’t flex at all, use a knife to scrape between its inner surface and the pot’s contents.
In some extreme cases, neither of these methods will be enough, so you may have to break or cut the pot to get the plant out.
How to fix root bound plants
Once you have the plant out of the container, take a close look at the root ball to determine how severe the problem is. You will need to move it to a less constrictive environment, either a larger container or the ground. Simply removing it from the original container and repotting it may not be enough, as some roots will continue to have trouble growing outward.
Along being root bound, the roots may have trouble penetrating a different soil type from the original potting medium. The roots will continue to coil as though they were still in a tight container.
For a lightly root bound plant, squeezing the tangled roots or using your fingers to untangle them before replanting may be all that you need to do. In more drastic cases, you may have to go a little further. Try soaking the roots overnight to soften them before attempting to work them apart.
Another widely recommended option is to slit the root ball. Make several vertical slits in it. Slitting the root ball doesn’t harm the plant; rather, it encourages new roots to grow out into the surrounding soil.
Some researchers have found that the box method of cutting the roots may be more effective than the others. Box cutting or boxing involves cutting away the sides and bottom of the root mass to give it a box or cube shape.
Alternatively, you can simply prune the roots. Cut away a portion of the root ball. How much you cut depends on the plant’s size. Prune the plant’s roots carefully, since cutting away too much can kill the plant.
After placing the plant with its detangled or pruned roots in a new container or the ground, water it thoroughly and take care to ensure that the plant continues to get adequate water, as this will help counteract the stress of repotting.
Note: The advice above applies to pepper plants, but doesn’t necessarily apply to all plants, since some do prefer to be root bound. Those plants include houseplants like peace lilies, ficus, and jades. All only flower and reproduce when they are stressed.