How to Repot a Plant—And When You Should Just Leave It Alone
Look to the roots for your answer.
Published Oct 31, 2021 1:16 AM
I hear “I think I need to repot my plant” a lot in my work as an interior plant designer. It’s the first place we mentally go when diagnosing a sign of stress (like clicking through WebMD when you’ve got the sniffles). However, it tends to be a more drastic solution than necessary. Even still, understanding how to repot a plant is important, and in the long run the practice is essential for the general health and growth of your greenery. So if you’ve ever wondered when is the right time to repot—or just been too intimidated to actually do it—read on to find out.
When to Repot a Plant
While you might be looking to rehome your plant because of the cool new planter you just picked up, the real reason to do it is to give the plant’s roots more space to expand, and in the process replenish the soil to give it the nutrients it needs to thrive. When is the right time to make a move? Thankfully there are a few main signs:
If Your Plant Is in Its Plastic Nursery Container
Even though plants can last for a while in their nursery pots, they’re not something you want to leave a plant in for more than six to 12 months. In fact, from grower to nursery to plant store to you, your plant will have lived and traveled quite a long time in its plastic home, so it will likely be in need of extra space and soil sooner than that.
If You See the Roots
Spot roots growing out of the hole in the bottom of your planter? This is a sure signal that the plant requires more room. Left too long in this state, your plant can become root-bound. Which brings us to the third sign…
If the Plant Is Fully Root-Bound
Remove your plant from its existing planter and check if its roots are wrapped around the root ball. If so, they’ve developed so much that there is little to no space for new growth, and no longer enough soil to retain moisture for the plant to drink from. Severely root-bound plants will have little to no soil visible. You may even notice that your plant’s container has been pushed out of shape by the pressure.
If Your Plant Is Unusually Thirsty
Unable to access or see the roots? A plant that’s very thirsty and completely dries out within a few days of watering could mean there’s not enough soil to soak up and hold the moisture. This can look like a case of underwatering, even though you’ve just watered.
If the Leaves Are Deformed or Oddly Small
The plant may not have enough space or nutrients to be able to produce full-size, healthy leaves; it’s time to repot.
If There Are Little or No New Leaves in Sight
This is especially indicative during the height of growing season (spring and summer), when your plant should be flourishing. It has likely been in the same container for quite some time.
When Not to Repot a Plant
If Your Plant Is Getting Much Larger and Producing New Leaves
It might sound obvious, but this is a sign that your plant is happy! It has enough space and nutrients in its pot; it’s best to just let it thrive.
If Your Plant Is Sick or Unhealthy
Repotting an already stressed plant can end up stressing it even more, potentially leading it to die. The more likely culprit is related to other issues, like light level, watering frequency, or a pest infestation. The only case in which you might want to repot is if the plant is suffering from root rot and needs a new dry home ASAP.
When You Need to Repot Again
When planted in a container 1 to 2 inches larger in diameter than its original nursery pot size, an average-size plant can most likely stay one to two years in the same planter. The repotting sweet spot is the spring and summer, when your plants undergo the majority of their growth.
The Best Soil for Repotting
Most tropical plant varieties want soil that is able to hold moisture. Generally, all-purpose potting soil is perfect for this, as it contains ingredients for moisture retention and aeration and also tends to be high in nutrients.
On the opposite side of the spectrum, succulents and cacti like a soil with a higher amount of aeration material so that water is able to run right through it, allowing it to dry out more easily. (Cactus roots are small and delicate, making them easily susceptible to root rot.) A cactus-specific soil will provide these guys with an environment that most closely resembles their native desert habitat.
The Best Planters for Repotting
One with a drainage hole is always my first suggestion. However, you can use a planter without a hole as long as you add drainage stones to the bottom to create separation between the roots and the pot. This ensures your plant will not be sitting in water whenever you give it a drink. The ones I generally recommend are expandable clay aggregate, as it not only acts as a barrier but also helps absorb excess H2O.
How to Repot a Plant
- Planter that is 1 to 2 inches wider than the plant
- A pair of pruners, scissors, or box cutter
- Drainage stones (if planter has no drainage hole)
Step 1: Get Drainage Sorted Out
If you’re using a planter without a hole, create a 1- to 2-inch layer of drainage stones at the bottom of the pot.
Step 2: Add Some Soil
Go ahead and put a layer of soil directly into the bottom of the planter (if it has a drainage hole) or on top of the drainage stones (if it doesn’t). Generally speaking, the combined layers of drainage stones and soil should take up about the bottom third of your container.
Step 3: Free Your Plant
If you’re taking it out of a plastic nursery pot, you can squeeze the sides to help loosen it or lightly tap the bottom against a counter or tabletop. Then, grabbing from the base of the stem, gently pull the plant out. Still stuck? Lay the planter on its side for extra leverage. Fair warning: If the plant is root-bound, you may have to resort to cutting it out with pruners.
If you’re excavating your plant from an existing ceramic or terracotta planter, simply pull up from the base of the plant stem with one hand while pushing down on the planter with the other. You may find that you need to wiggle the plant or loosen the surrounding soil in order to get it out.
Step 4: Inspect the Roots
Young plants with very small or already loose roots can go directly into their new planter. On the other hand, if the roots are tangled or root-bound, gently tease and detangle the ends with your fingers to loosen them and encourage them to grow into the new soil. You want to massage and coax the roots free rather than yanking them, so go easy. In extreme cases, where the plant is very root-bound, you may need to use more force or even cut the roots apart.
Step 5: Secure the Plant With Soil
Place the plant in the center of the new pot. This is a good opportunity to quickly see if the plant is sitting too high or too low. If too low, take out the plant and add a bit more soil. If too high, remove some soil from either the planter or the bottom of the root mass.
Once you’re happy with the height, use one hand to hold the plant in place and upright. Use the other to add soil around the sides of the plant, gently packing it down as you go to make sure the plant is supported. Continue doing this until you’ve almost reached the top lip of the planter. Leave a ½ inch to an inch free of soil, so that when it comes time to water, it won’t flow over the edge of the pot.
Step 6: Tidy Up
The hard part is over! Now that you’ve potted your plant (congrats!), wipe off the planter with a rag and give the plant a good drink right away—or after one to two weeks if it’s a succulent or cactus. Just like us, greenery needs to settle. Water will help it stay hydrated as it adjusts to its new home.