For most plants, repotting is typically done every one to two years. Exceptions include slow-growing plants such as succulents, which only need repotting every three to five years.
As a plant owner, you need to be attentive to the needs of each individual plant and know the signs to look out for in case the plant needs to be transferred to a larger pot.
In this article, we will discuss more how often one should repot houseplants, why they need to be repotted, and how to properly repot a houseplant.
If you are thinking about repotting your plants and you want to learn more, keep reading.
Why is it necessary to repot a houseplant?
The plant is unable to grow bigger in a small pot
Basically, when the plant has become too big for its pot, its roots will no longer have space to grow and develop. The plant will stay only as big as the pot allows until it is mercifully transferred to a larger pot. No matter how hard the plant tries to grow, its new leaves and roots will only end up suffocating it, so it will start to actively refrain from growing, which is why stunted growth is one of the signs that a plant needs repotting.
Compare your potted plant to one that grows in the ground: A plant in the ground will not have the space constraints nor the nutritional restrictions that a potted plant does.
The soil needs to be changed
Another reason repotting is necessary is that the soil in the pot is no longer doing the plant any good. It may be contaminated with bacteria or fungi that cause root rot, it may no longer be sufficiently well-draining and thus cause the plant to become overwatered, pests may have overtaken the soil, or it might have been in the pot for so long that it is depleted of essential nutrients and minerals.
Even if the size of the pot is not an issue, the soil itself may need to be changed for the well-being of the plant.
The old pot is too small to propagate the plant in
Some plant owners like to root their cuttings in the same pot as the mother plant before moving it to its own pot. If the mother plant’s pot is already quite snug just for the mother plant, then you will not be able to use the same pot to grow your cuttings. It will become too crowded, which will affect not only the overall health of the cuttings but of the mother plant as well.
How often to repot plants
Most houseplants usually need to be repotted once a year or once every two years. This is true for plants that are transferred to a pot one size bigger than the previous one.
Houseplants that are well cared for will grow fast, and if the need to repot arises quickly for you, it means you are doing most things, if not everything, right by your plants. You should be ecstatic that your plants constantly need repotting, because it means they are happy and healthy.
Plants that are slow-growing, like most succulents, only need to be repotted every three to five years. If you are the type of person that may not have the time to look after fast-growing plants, then maybe succulents are more your speed.
There really is no set time frame to follow when it comes to repotting your plant. The best way to know is to look out for signs that the plant needs repotting.
How will I know when my plant needs to be repotted?
As mentioned above, you cannot just follow a schedule to know exactly when to repot your plant. If you do this and are repotting all of your plants once a year just because one or two plants look like they need it, you are putting your other plants through unnecessary stress that will take a toll on their general well-being.
Research each of your plants first, and read about the signs to look out for to know that that specific plant really does need repotting.
Signs that your plant needs to be repotted
Your plant is not no longer growing outward
One of the signs that your plant needs to be repotted is when it no longer seems to be growing sideways but is just getting taller. This may be because the roots in the pot no longer have space to grow into. This pushes the plant upward, creating the illusion that the plant is growing, but in reality it is just being pushed out of the pot by the overgrown roots.
The drainage holes at the bottom of the pot are blocked by roots
Another sign that your plant needs repotting is when you can see roots growing out of the drainage holes at the bottom of the pot. This means there is literally no space left inside the pot for the new roots to fill, so they grow out of the drainage holes to try and reach more soil. A secondary issue caused by this blockage is that excess water is prevented from flowing out of the holes. The water will stay in the soil around the roots and this can lead to root rot.
You can test whether the holes are blocked by watering the plant and waiting for the excess water to flow out of them. If, despite pouring plenty of water into the soil, there is still no water flowing from the drainage holes, that is a good indication that the pot is full of roots and will need to be repotted.
Your plant is becoming too big
Sometimes you can just look at your plant and see that the pot seems dwarfed by the actual plant. This is a clear sign that the pot is way too small. You need to repot the plant as soon as possible because it might become top-heavy and end up tipping over, possibly even cracking the pot because of the overgrown roots.
The soil is compacted
The longer the same soil is kept in the pot, the more compacted it will become. Compacted soil makes watering the plant much more difficult because it can become almost hydrophobic, meaning it will be extremely difficult for water to penetrate it. If you pour water on top of compacted soil, it will stay on top of the soil until it evaporates, and only very little water will actually penetrate the soil. The wet top layer of soil can fool plant owners into thinking that the soil has been properly soaked, even if not more than the top inch got wet.
You need to change compacted soil as soon as possible because fresh, loose soil will make the plant much happier.
Some people try to just add more soil to the top of the compacted soil thinking that this will fix the problem, but this will actually make the already-compacted soil even more compact.
Mineral buildup in the soil
If you regularly fertilize your plants, there will likely be a significant buildup of nutrients and minerals in the soil. Most of this buildup is on the surface and will look like a crusty layer on top of the soil. This layer will keep the water from penetrating the soil and the roots will not get the water they need. This can lead to the plant becoming underwatered and possibly dying.
What time of year is best for repotting?
Most plants actively grow during the summer and it is best not to disrupt this by repotting the plant. This is especially true for plants that are slow-growing.
However, repotting during the winter is also not advisable, because most plants are dormant during this period. Remember that repotting is a stressful experience for the plant, so repotting it when it is not actively growing also means that its recovery will take a lot longer.
Ideally, repot the plant during the tail-end of winter or the start of spring, so that it can recover well without interrupting its main growth period.
How to repot a plant
First, you need to prepare a new pot that is the right size for the plant. If the old pot is still big enough and all you need to do is to replace the soil, then reusing the old pot is perfectly fine.
However, if the plant does need a larger pot, pick one that is two to four inches bigger in diameter than the old pot. Just make sure the new pot is not too big, because a larger pot means more soil, and more soil means more water is retained. This means that the soil will be wetter for longer, which can lead to overwatering and even root rot.
After you have chosen a new pot, water the plant the night before you plan to repot it. This way, the plant is well-hydrated and happy before putting it through the stressful process of repotting.
The next day, lay the plant down on one side and use an old knife to loosen the soil from the sides of the pot. Gently pull the plant out of the old pot, doing as little damage as possible to the roots. Ironically, the more rootbound the plant, the easier it is to pull it out of its old pot because the entire root mass will be clumped together.
Clear away as much of the old soil as possible and find the root ball beneath the soil. If there are any roots that are brown, black, mushy or dry, you need to remove them with a sterilized knife or scissors. If the root mass is too large, trim it using a saw so that the roots can fit inside the new pot.
Place the plant in the new pot and hold it in the pot’s center. Fill the gaps around the roots with fresh soil until the soil comes up to near the rim of the pot. Gently press the soil down, but do not pack it in because plants like their soil to be loose and airy.
Lastly, water the newly repotted plant and place it in a spot where it can get the levels of light it needs.
Most plants usually need to be repotted every one or two years. This is, of course, dependent on the type of plant, and you should do your research to know the average time between repotting for your specific plant.
Plants that are slow-growing often only need repotting every three to five years.
The need for repotting is based more on the current state of the plant in its pot rather than a fixed number of years. It is, therefore, better to know the signs of a plant that needs repotting than it is to just repot the plant on a fixed date.
Image: istockphoto.com / deniskomarov