Repotting houseplants: when, how & what soil to use

Houseplants are a lovely way to spruce up any home. Given the right care, you can enjoy them for a long time to come. Among other things, repotting houseplants regularly is an essential part of houseplant care.

Repotting houseplants is fairly simple. Taking a few important tips into account will ensure your greenery quickly begins to push out new growth. Read on to find out how to know when it is time to repot and how to do this.

When to repot houseplants

The best time to repot houseplants is in the spring between February and April. This is when the growing period begins, so once your houseplants are in new soil, they can immediately start producing new leaves. Though not ideal, it is also possible to repot houseplants in winter or indeed any other time of year in the event of a pest infestation, for instance.

Signs that it is time to repot your plant:

• If the plant is root-bound and roots are protruding out of the top of the pot or growing out of the drainage hole at the bottom.
• White lime and salt deposits are visible on the surface of the soil.
• If the soil starts to sink or pulls away from the sides of the pot and no longer absorbs water well.
• If the plant stops growing or you notice signs of nutrient deficiency.

• If there is a pest infestation – especially pests that like to stay in substrate such as fungus gnats, but also pests such as springtails, which can multiply uncontrollably.
• You should never wait too long to repot newly purchased plants. They are often sold in depleted soil or in pots that are too small for them.
• If the plant has formed multiple offshoots. These could do with a little more space, so it is best to separate them from the mother plant and plant into a new pot.

Tip: Be careful when repotting, especially with plants that are sensitive to disturbances, such as citrus plants or the fiddle-leaf fig. It is best not to repot these too often as repotting can be stressful for the plant. Slow-growing plants, such as cacti and other succulents, rarely need repotting.

What soil to use for repotting houseplants

When it comes to knowing which is the best soil for repotting indoor plants, this depends primarily on the plant itself. Here is a brief overview of which substrate is suitable for which group of plants:

All-purpose compost: All-purpose compost can be used for any houseplant that does not have special requirements for its substrate. It is suitable for plants such as lychee trees, elephant ear plants, monsteras, peace lilys, hoya, prayer plants or Philodendron scandens.

Our Plantura Organic All Purpose Compost is a high-quality and environmentally friendly compost with a pH value of 6.1 to 6.9, making it suitable compost for repotting houseplants. It also contains all the essential nutrients that plants need for a good start in life.

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Tip: You can use all-purpose composts as the base ingredient for mixing your own substrate for houseplants with more specific requirements, such as cacti.

Flower compost: Flower compost is usually suitable for flowering plants such as cyclamen, hyacinths, flame lily, blood lily, bottlebrush, geraniums or hibiscus. So, if you have houseplants that also flower, it is best to opt for such compost. We again recommend using a high-quality substrate, such as our Plantura Organic Flower Compost. Compost for flowering plants usually contains slightly more phosphate than all-purpose compost which helps encourage abundant flowering.

Succulent and cactus soil: Succulents and cacti, such as Aloe vera or Haworthia, require a well-draining substrate that is very permeable to help prevent waterlogging. You can easily mix this substrate yourself. Simply use some all-purpose compost as the base; it should make up about half of the mixture. Next, add around 20% quartz sand and for the rest, mix in some pumice and crushed expanded clay.

Palm soil: Palms such as areca palm or Kentia palm also require a slightly more permeable soil. Of course, there are many species of palms that come from different regions, each of which have their own specific requirements. Generally speaking, however, you can use a mixture made up of all-purpose compost and about one-third quartz sand. As palms love a slightly lower pH, it is also advisable to add in some acidic soil.

Herb compost: For Mediterranean kitchen herbs on balconies and windowsills, it is best to use special compost specifically for herbs. Rosemary, thyme, lavender, savory and marjoram thrive in well-drained, low-nutrient soils. They also develop a much more aromatic flavour when grown in such soil. Our Plantura Organic Herb & Seedling Compost is not only suitable for Mediterranean kitchen herbs, but it also a sustainable and peat-free option with a much lower carbon footprint.

Tip: Basil, parsley, chives, dill, mint, lovage and wild garlic, on the other hand, require a nutrient-rich soil. Rich, all-purpose compost is ideal and provides them with all they need for healthy growth. Some plants, such as orchids or carnivorous plants, require a special substrate mixture that is not so easy to mix yourself. In this case, it is best to use a soil that is precisely tailored to the needs of these plants. We have plenty of articles available for you to read and learn about the soil requirements of a wide variety of houseplants.

How big should the new pot be?

If for whatever reason you need to repot your plant, but there is still space between the root ball and the current pot, you do not need to use a larger pot. Simply replace the old soil for fresh soil. If a plant is root-bound (i.e. the roots fill the pot) the new pot should be no more than sizes larger than the old one. Ideally, there should be around 3 cm between the root ball and the edge of the new pot.

Repotting bonsai trees is slightly different, as they are meant to be kept small. After pruning the roots, simply plant the bonsai in its old pot or in a slightly larger one.

Tip: Refrain from repotting into too large a pot. If the new pot is too large, the plant will have less support and the soil around the root ball will remain moist for longer, making the plant susceptible to root rot.

How to repot houseplants

Follow our short step-by-step guide on how to correctly repot your houseplants:

1. It is important to wear gloves when repotting poisonous or prickly houseplants. To make repotting larger houseplants easier, you can carefully place the plant on its side.
2. First, check whether the plant needs a larger pot. To do this, carefully lift the plant from its current pot and assess the root ball.
3. Prepare the new pot by creating a drainage layer at the bottom. To do this, simply place a layer of clay shards, pebbles or expanded clay on the bottom of the pot.
   Tip: Placing a sheet of jute between the substrate and the drainage layer will ensure everything remains neatly separated, meaning you can later reuse the drainage material.
4. Add a layer of soil to the pot. This is the perfect time to mix in a granular fertiliser to provide the plant with nutrients long-term.
5. Lift the plant out of its pot and gently remove the old soil from the root ball as best you can. Carefully loosen the roots with your fingers and remove any rotten roots. If the roots are growing out through the drainage hole, making it difficult to remove the plant from the pot, it is best to cut the pot with scissors if possible.
6. Next, place the plant in the new pot. Fill any gaps with soil, leaving about 3 cm of space from the rim of the pot, so that it does not overflow when watering.
7. Gently tap the pot on the table a few times to distribute the soil between the gaps. Next, gently press everything down.
8. Finally, water the soil so that the substrate is nice and moist.
9. Cover the substrate surface with a layer of mulch to prevent mould growth on the soil and prevent a fungus gnat infestation.

Tip: Some plants can also be divided when repotting. To do this, carefully separate the plant at the root ball. Then, plant the two now separate plants into individual pots.

Repotting aftercare

There are a few things you need to do to keep your plant happy after repotting. Firstly, it is best not to place the plant in direct sunlight after repotting to avoid drought stress. Secondly, if you had to remove some of the roots (due to parasites or root rot), you will also need to slightly prune part of the plant above ground. Otherwise, the roots may not be able to provide enough water for the plant.

After repotting, the fresh soil provides the houseplant with the necessary nutrients. You therefore only need to water regularly during the first two months so that the root ball does not dry out. Around eight months after repotting, you can then apply fertiliser again. The nutrient requirements differ depending on the plant:

Houseplant fertiliser: Plants with decorative foliage need houseplant fertiliser that helps strengthen the leaves and roots. Our Plantura Liquid Houseplant Food is a great choice. In addition to the key nutrients nitrogen and potassium, the microorganisms in this fertiliser also support the growth of your plant. Among others, this fertiliser is suitable for houseplants such as monstera or anthuriums, for instance.

Flowering plant fertiliser: Plants that produce flowers, such as geraniums and amaryllis, require different nutrients to other houseplants. Our Plantura Liquid Flower Food is particularly suitable for flowers, among other things.

Mediterranean and citrus plant fertiliser: Mediterranean and citrus plants also require different nutrients and often a lot of potassium and iron in order to produce fruits. Fertiliser made specifically for Mediterranean plants, such as our Plantura Liquid Citrus Food, contain sufficient quantities of these nutrients. Our fertiliser also contains microorganisms that encourage and support the growth of strong and healthy roots. It is suitable for all citrus plants, such as lemon trees and olive trees.

How often and how much you need to fertilise and water depends entirely on the plant. For further information, check out our in-depth articles on fertilising houseplants and how to water houseplants.