How To Prevent And Fix Root Bound Cannabis
When cannabis is grown outdoors in garden beds, plants can normally spread their roots without restriction. However, when we grow cannabis in containers, plants becoming “root bound” can become a problem. Find out what root bound means; how to recognize it, and what you can do if it happens to you.
Most cannabis cultivars, at least in colder climates, grow indoors in a tent or in a dedicated grow room. Growing indoors in containers means there is the risk of your plants becoming root bound. When this happens, it can lead to all sorts of growing problems. Let us take a closer look at what “root bound” means. Learn how to recognise the signs, so you can fix the issue and prevent it from happening in the future.
WHAT IS ROOT BOUND?
When your plants are root bound, it means that the roots have outgrown their container and don’t have any more room to grow. This of course happens when your containers are too small for any given reason. Outdoors in garden beds, plants becoming root bound is less likely, although it can happen when roots hit restricting barriers such as pipes or large rocks underground.
WHAT ARE THE SIGNS OF YOUR PLANTS BEING ROOT BOUND?
A healthy root system plays a vital part for your plants’ growth. After all, it is with their roots that plants take in water and nutrients.
Plants becoming root bound can lead to all sorts of issues. Here are some of the most common signs and symptoms that your plants may be root bound:
Your plants may show symptoms of nutrient deficiencies. Among these signs could be yellowing, spots, or crumbling and wilting leaves. If you can exclude other issues such as incorrect pH, nutrient issues, and overwatering, your plants may indeed be root bound.
Containers Drying Out Too Quickly
When you find that the soil dries out after only a day or two and you need to water very often, it means that your plant needs more water than the container can hold.
Plants Get Way Too Big And Unsturdy
When your plants have grown too tall for their container size, they may easily tip over. This is usually a sign that your plants have become root bound, and that you should transplant them into bigger pots.
Other potential symptoms include:
- “Nutrient burn” without excess nutrients: If you spot the signs of nutrient burn, but you are feeding your plants only lightly.
- Smaller buds with stunted growth: If your buds grow smaller, or your plants’ overall growth is slower than usual.
- Sick plants, wilting, drooping: If your plants have a sick appearance or start to wilt or droop unexpectedly.
WHAT TO DO WHEN YOU SUSPECT YOUR PLANTS ARE ROOT BOUND
If your plants show one or more of these symptoms, you need to look at their roots to see whether they have become root bound. To do this, you will need to remove them from their containers. Sometimes, it may be quite obvious that your plants have outgrown their containers, say when you see the roots through the holes at the bottom. Time to give your plants a new and bigger home!
HOW TO SAFELY REMOVE PLANTS FROM THEIR CONTAINER
You want to be careful when you remove plants from their containers in order to not damage the roots.
Get a good grip on your plant’s stem, right above the soil line. Rest your hand on top of the soil so that the stem is between your fingers. Carefully flip over the whole plant and then try to pull off the container. Most of the time, the container should come right off.
If you have troubles pulling off the container, carefully squeeze the container a few times around the side. This helps to loosen up the soil inside.
If your plant is still refusing to come out, take a long knife and use the back edge to slide around the inner edge of the container. If your plant is so severely root bound that nothing will help to remove it, consider breaking open the container as your last option.
FREE THE ROOTS: HOW TO LOOSEN THE ROOT BALL
When you have managed to pull out your root bound plant from the container, the roots will be running in a tight circle in the shape of the container. The roots are trapped and unable to grow freely any longer. Before you replant into a bigger container, you should try loosening the compact mess of roots so they can spread out again. You can carefully do so with your fingers.
PRUNING THE ROOTS
In severe cases of root bound plants, you may not be able to loosen the root ball with your fingers alone. You will then have to prune the roots to free them. By using a sharp knife, cut a few top-to-bottom incisions into the outer layer of the tightly-packed root ball. But be very careful and only cut thin roots. Do not cut any thick tap roots! 2-3 incisions evenly spaced out around the root ball should be all that you need to free the roots so that they can grow outwards again.
REPLANTING YOUR CANNABIS PLANT INTO A NEW CONTAINER
Take a new container with enough room so that your plant’s roots have plenty of space to expand. Fill the container with some soil, make a hole, and then align your plant in the middle. Make sure that your plant is at about the same soil level as you had it before. Likewise, ensure that you do not pack the soil too tight; the roots should be able to grow freely without trouble. After you have placed your plant in its new container, water the soil. At this point, you can also add root stimulant to help with things.
Your previously root bound plant is now happily sitting in its new and big container, but it is going to be quite sensitive for some time. To help it to recover from the transplant shock, you should keep stress levels low for a few days. Feed it only lightly and if you can, turn down your lights a notch or two as well. You will know that your plants have fully recovered once you see new, healthy growth. When this happens, which can take between a few days to a couple of weeks, you can return to your normal lighting and feeding schedule.
HOW TO PREVENT YOUR CANNABIS PLANTS FROM BECOMING ROOT BOUND
Preventing your plants from outgrowing their pots and becoming root bound is not difficult. Simply choose large enough containers from the start so this won’t ever happen. If you plan to replant during a grow, up-pot into bigger containers before it’s too late. Don’t wait until your plants have outgrown their current containers.Learn about root bound cannabis plants and how to prevent it from happening in your grow-op.
How to Help a Rootbound Cannabis Plant
It can be hard to know exactly when to transplant your cannabis plants into a new container because it is rootbound. This rootbound cannabis guide and tutorial will share some pictures and scenarios where you might consider transplanting your plants:
Soil is drying out too quickly – When your container is drying out only a day or two after each watering it means your plant is drinking fast and may need more water than your current container can hold
Plant is getting root or nutrient problems – A cannabis plant can start showing rootor nutrient problems when it’s kept in a too-small container or if it’s become root-bound. These root problems can cause the plant to become droopy, or show unexpected leaf symptoms or deficiencies (such as spots or yellowing leaves). Whenever literally everything else is right but you’re still experiencing these problems, it may be a sign you need to transplant.
Plant has grown a lot or been in the same container for months. If you’re keeping a mother plant for months, or if a plant has doubled in size in the same container, those are signs you may need to transplant to prevent your plant from getting rootbound.
Plant is tipping over from its own weight. When your cannabis plant is much wider and taller than its container, it’s easy to tip over and therefore should be transplanted to a bigger pot that can hold it steady.
Plant is just plain too big for container (pics below) – There are some pictures below to give you an idea of what a plant looks like that needs to be transplanted. Some plants are just plain too big for the containers they are in.
Now let me give you a few real-life examples you can use to refer to. The following transplanting pictures should help give you an idea of exactly when to transplant your cannabis plants!
These marijuana plants are ready to be transplanted
This cannabis seedling is ready to transplant – you can transplant a cannabis plant from a solo cup once its leaves reach the edges. Don’t wait much longer than this for a seedling in a solo cup!
This next cannabis seedling is huge for a solo cup – it should have been transplanted weeks ago! The strange curling symptoms are a sign that the roots aren’t happy. Once this plant was transplanted it started growing perfectly again.
Sometimes a rootbound cannabis plant shows strange symptoms that almost look like nutrient deficiencies and/or overwatering, when the real problem is it just needs a bigger container!
This next marijuana plant is also way too big for its solo cup. Although it still looks relatively healthy, notice the yellowing bottom leaves with spots and bluish color. If this plant isn’t transplanted to a bigger container, those leaf symptoms will continue moving up the plant and start causing problems. Additionally, most likely this plant would already be much bigger if its roots weren’t being constrained by the solo cup.
These marijuana plants aren’t showing symptoms yet, but they’re getting too big for their pots and should be transplanted soon, especially before they start flowering!
These cannabis plants are way too big for their containers and they’re starting to show strange leaf symptoms, drooping and curling because roots aren’t getting what they need
When a cannabis plant is much wider than its pot, it should be moved to a bigger container even if it’s not showing signs of being root-bound. Not only will the plant roots love the extra space, your plant won’t be so easy to tip over!
This cannabis plant was not transplanted before it started flowering. Although it was healthy its whole life, in the middle of the flowering stage it started drooping and showing these symptoms, because the plant was rootbound. Although it’s generally not recommended to transplant a marijuana plant in the flowering stage, that’s what was needed to fix up this plant and get to harvest!
How to Transplant Cannabis
Water your cannabis plants 1-2 days before transplanting. This will help the growing medium stay together (since it’s moist), but still slide out easily (since it’s not soaking wet).
Before you get started, fill your new pot with potting mix. Don’t fill the pot to the top, instead leave about 2 extra inches (5 cm). That way you can easily water the plant without all the water running off the sides.
Water this new container of potting mix before you begin the transplant so it’s nice and moist. If you don’t water the new soil first, it can have a hard time absorbing water after the transplant, and your roots won’t like that!
Since you will soon be adding a new plant, you want to dig out a hole in the middle that’s about the size of your old container.
Take your plant, and carefully slide a butter knife inside the container all around the edges to help separate the rootball from the sides of the pot. Avoid grabbing the plant directly by the stem. Try to grab the whole top with a flat hand, and turn the container upside down so you can gently pat the rootball out and catch it with your flat hand. You may have to gently pull the plant out of the container, but go slowly and be gentle!
Plant the rootball directly into the new container, placing it in the hole you dug out earlier. You may need to add some extra soil to ensure a nice flat topsoil.
Gently pat down around the roots, to help press everything together slightly, then water your plant immediately. If you do it right, it won’t stress your plants at all! Read a few more tips here.
More on Cannabis Life Stages…
- Vegetative Stage (Getting Bigger)
- Flowering Stage (Making Buds)