Repotting Your Houseplants

Repotting Your Houseplants

Introduction

Most houseplants can tolerate some neglect and can survive being left in the same pot for several years. But if you want your plants to thrive rather than merely survive you will need to master the art of repotting.

Houseplants need repotting when they have outgrown or exhausted the compost they are growing in. Repotting allows indoor plants to continue growing and remain healthy. Most houseplants need repotting every one to two years, although some of the more rampant growers such as the spider plant (Chlorophytum comosum) and Swiss cheese plant (Monstera) may need repotting more frequently.

Houseplants needed to be repotted in an appropriate medium. In most cases a general houseplant repotting mix, such as Houseplant Focus Compost, Westland Houseplant Compost, or Miracle-Gro Premium Houseplant Potting Mix. However, certain groups of plants such as cacti or orchids require specialist potting mixes. We will investigate these composts later on.

I do not recommend repotting houseplants in a general (garden) multipurpose compost for a number of reasons. Firstly, the garden mixture may be too rich and cause a burst in lush, weak growth. Secondly, it is coarser and less well sieved compared to a houseplant mix. In other words, it may contain large chunks of wood and inorganic matter. Thirdly, general multipurpose compost isn’t as clean as houseplant compost, especially if it has been opened and stored outside for a while. Finally, once you open a bag of compost it begins to degrade. If you want to use a general multipurpose compost for repotting your houseplants then I recommend you always use a fresh sack, and that you use a garden sieve (called a riddle) to remove and large woody lumps and other debris. It is much more convenient to buy a small bag of houseplant compost when you need to re-pot a houseplant.

The 5 Dos and Don’ts of Repotting.

1) Do your repotting when you plant is in active growth.

For many houseplants the best time to undertake repotting is spring. This is because many plants are about to start a new growing period after resting over winter. However, autumn can also be a good time to re-pot, as many houseplants will still have a couple of months growing to do before winter.

2) Don’t re-pot your plant unless it actually needs repotting.

When you first buy a houseplant the pot will be fine, but after some time it will become too small. There are some simple signs to look for to see if a plant needs repotting.

Firstly, lift the plant up in its pot and turn it upside down. Can you see any roots poking out of the drainage holes? If you can see roots emerging from the holes then there is a good chance that it needs repotting. If you are not certain, then gently tip the plant out of its pot to inspect the whole root system. If the pot is packed with roots then the plant is ready to be repotted.

Secondly, a plant needs repotting is if it seems to be struggling for space in its pot. Some plants, for example the ZZ-plant (Zamioculcas zamiifolia), will make it obvious when they need repotting as their thick roots and rhizomes will start distorting their pots when they get pot-bound.  While other plants, like the Peace lily, produce a mat of roots on the surface of the soil when they become pot-bound.

Finally, if you have been overly generous with the watering, your plants may need repotting in the same pot but in fresh compost to save them. This is because excess moisture in the compost causes roots to rot. If this is the case you will need to remove any diseased or rotting roots with a sharp knife, and prune back the plant to compensate for the loss of roots.

3) Do use a pot with drainage holes.

Drainage is important for houseplants. Getting the watering right is the key to having healthy, happy houseplants. In my experience, overwatering is the most common cause of poor health and death for pot plants. Using a pot with drainage holes is the easiest way of ensuring your plant doesn’t run the risk of sitting in excess water. Drainage holes allow air to the roots, and they also allow the flushing away of excess salts from the soil. There is another straightforward reason, it is much easier to water a plant with drainage holes.

The traditional way to grow houseplants is to use a pot with drainage holes and sit it on a saucer to catch the excess water. At Capital Gardens we stock a range of plastic plant pots and matching saucers in terracotta, black and green. We also offer bamboo pots by Haxnicks made from sustainable natural materials – these come in sage-green and terracotta, with matching saucers available.

Expert Tip: New terracotta (clay)pots should be thoroughly soaked in clean water before use.

To crock or not to crock? Traditionally a layer made of broken clay pots (crocks) or gravel was placed at the bottom of a pot to improve drainage. This practice is not now recommended because modern compost mixes drain uniformly, and the crocks just raise the pot water-table nearer to the roots.

https://www.bbc.co.uk/news/blogs-magazine-monitor-27126160

Pots Without Drainage.

So, you’ve seen a beautiful pot on our shelves, but it has no drainage. Do you just forget it and go for a plain pot with drainage holes?

The one thing I always tell houseplant customers is never to plant directly into a cover pot. “Can I plant it directly into this cover pot?” is one of the most asked questions I get working with houseplants. I always say, “I don’t recommend it”. Or just, “No!”. Or even, “No! not even with a thick layer of gravel at the bottom.” – and yes, you know who you are!

Relax. This doesn’t mean you can’t buy that beautiful cover pot that will fit so well with your new décor – just keep the plant in its plain pot! In other words, keep your plant in its plastic pot and use the decorative pot as a cover. Then you can simply lift the plant out for its watering and place it back when you’ve finished.

Expert Tip: Don’t buy a cover pot that only just fits. Pick a larger size that makes is easy to lift the plant in and out. This also means that you will be able to re-pot the plant into a larger plastic pot as it grows and use the same cover pot to display it in.

4) Do choose an appropriately sized pot. Use a clean pot that is one or two sizes larger than the original. Do not be tempted to over-pot. In other words, don’t move the plant into a pot that is significantly larger than the one it already is in. This is because over-potted plants are at risk of root-rot due to excess moisture retention by the extra volume of compost.

5) Do use a suitable, fresh potting compost. As already discussed, use fresh houseplant compost when you are repotting. General houseplant repotting compost is appropriate for most houseplants.

However, some plants groups require specialist composts. What might be a good compost for one plant may not be suitable for another. For example:

1. a) Cacti and succulents. These need a free draining potting mix such as Westland Cacti and Succulent Potting Mix or Cactus & Succulent Focus Repotting Mix.

Expert Tip: I add about a third of horticultural grit to cacti and succulent potting mixes and blend it in well. This sharpens the drainage and adds weight to the mixture.

1. b) Orchids. Only re-pot orchids if they are beginning to climb out of the pot, or if their roots look like they are beginning to rot. Commercially grown orchids are usually started on a plug of compressed coir (coconut fibre) which should be removed when you are repotting. Always use a proprietary orchid mix such as Orchid Focus Repotting Mix or Westland Orchid Potting Mix. Orchids such as the moth orchid (Phalaenopsis) should be repotted in a clear plastic pot because the roots are attracted towards the light. Moth orchids can be repotted at any time of the year when they need it.

To learn more about repotting moth orchids visit:

https://www.rhs.org.uk/advice/profile?pid=388

1. c) Citrus plants. Using a specialist loam (soil) based compost that provides the optimum nutrients will result in a healthier citrus plant. A loam based compost helps retain nutrients essential for fruit formation. Westland produce a specialist Citrus Potting Mix.
2. d) Carnivorous plants. Insect-eating plants grow best in a low nutrient ericaceous (acidic) potting medium. Carnivorous Focus Potting Mix is suitable for these plants.

To learn more about growing carnivorous plants, visit:

https://www.gardenersworld.com/plants/10-tips-for-growing-carnivorous-plants/

Top Tip: If you need advice about a finding the right compost for repotting a specific plant our Houseplants Experts can advise you and suggest an appropriate mix.

6 Steps To Successfully Re-Pot A Houseplant.

1) Gather together all the things you will need before you start. This will include the correct potting mix and a new pot of the appropriate size (with drainage holes). You will need somewhere to work where you can make a mess and clear it up. In warm weather it is easier to take your houseplants outdoors for repotting. Other items useful to have include a pair of gardening gloves and a hand trowel for scooping compost.

2) Water the plant 24 hours before you re-pot it. It is easier to get a plant out of its pot and keep the root-ball intact during repotting if you do this.

3) Once you have taken the plant out of its pot use the opportunity to look at the roots in case there are pests such as root mealybugs: https://www.rhs.org.uk/advice/profile?pid=201

If you discover any problems with the roots then treat them before proceeding with repotting.

4) Fill the quarter bottom of the new pot with fresh potting compost. Place the root-ball of the plant on top of this layer. Ideally, you want the soil line to be 2 to 3cm below the top of the new pot, so that when watering your plant, the water will stay in the pot and won’t simply run-off.

5) Fill the pot around the edges until the plant is sitting at the same level as it was at in the original pot.

6) Do not press the soil down. A light tapping of the pot on hard surface is sufficient to settle the compost. I wait a few of days before I first water a repotted plant. This is because the plant has already been soaked to get it out of the old pot, and it gives any damaged roots the chance to heal, reducing the risk of rot. After the first watering the compost might sink in a few areas. These areas can be filled with some more compost.

Expert Tip: When repotting a plant growing up a moss pole don’t be tempted to untangle the plant from its pole and reattach it to a longer pole. Simple purchase a moss pole extension section and connect the two together after you have repotted the plant.  Alternatively, you can add a taller moss pole behind the shorter original pole.

To learn more about choosing and growing indoor climbing plants:

https://www.capitalgardens.co.uk/blog/social-climbers/

Plants with aerial roots such as Monstera, moth orchids and Anthurium need special attention. These special roots appear above the surface of the soil and should not be cut off nor buried in the soil when repotting.

More Thoughts On Repotting.

If your houseplant is very slow growing, or you don’t want it to grow much bigger then you can re-pot it back into its pot using some fresh compost after brushing some of the old soil from the root-ball.

If you have a large houseplant in a massive pot then you may no longer have the strength or space to move it up to a bigger pot. Instead, you can refresh the compost at the top of the pot every one to two years. To do this simply break up the surface soil using a hand fork and remove as much of the soil as possible. Then top it back up with fresh compost.

Knowing which plants need specific composts opens up the possibility of creating indoor gardens. Planting up groups of plants that need the same soil and conditions gives you the opportunity to be creative. For example, you could design a desert landscape with cacti and succulents, or a mini-swamp with carnivorous plants.

In Conclusion.

For most people spending time caring for houseplants is pleasurable. If you dread repotting, then think of it as a chance to give your plant a health check as well as basic maintenance, and you will find you will become confident with the needs of your individual plants and how to get them to truly flourish.

Repotting should only be done when a plant needs it, that is when the plant has out-grown the pot. Don’t be tempted to over-pot, because moving a plant into a much larger pot may cause more harm than good. Remember, plant pots should have drainage holes and cover-pots (cachepots) are used for aesthetic reasons. Choosing a nice cover-pot is a great way to freshen the appearance of a houseplant and add texture and colour to a room.

There is no secret to repotting. All you need to do is to provide the plant with an appropriately sized pot with drainage holes and the correct potting mix. So why not take a closer look at your houseplants and see if any would benefit from repotting and a tidy up?

Introduction

Most houseplants can tolerate some neglect and can survive being left in the same pot for several years. But if you want your plants to thrive rather than merely survive you will need to master the art of repotting.

Houseplants need repotting when they have outgrown or exhausted the compost they are growing in. Repotting allows indoor plants to continue growing and remain healthy. Most houseplants need repotting every one to two years, although some of the more rampant growers such as the spider plant (Chlorophytum comosum) and Swiss cheese plant (Monstera) may need repotting more frequently.

Houseplants needed to be repotted in an appropriate medium. In most cases a general houseplant repotting mix, such as Houseplant Focus Compost, Westland Houseplant Compost, or Miracle-Gro Premium Houseplant Potting Mix. However, certain groups of plants such as cacti or orchids require specialist potting mixes. We will investigate these composts later on.

I do not recommend repotting houseplants in a general (garden) multipurpose compost for a number of reasons. Firstly, the garden mixture may be too rich and cause a burst in lush, weak growth. Secondly, it is coarser and less well sieved compared to a houseplant mix. In other words, it may contain large chunks of wood and inorganic matter. Thirdly, general multipurpose compost isn’t as clean as houseplant compost, especially if it has been opened and stored outside for a while. Finally, once you open a bag of compost it begins to degrade. If you want to use a general multipurpose compost for repotting your houseplants then I recommend you always use a fresh sack, and that you use a garden sieve (called a riddle) to remove and large woody lumps and other debris. It is much more convenient to buy a small bag of houseplant compost when you need to re-pot a houseplant.

The 5 Dos and Don’ts of Repotting.

1) Do your repotting when you plant is in active growth.

For many houseplants the best time to undertake repotting is spring. This is because many plants are about to start a new growing period after resting over winter. However, autumn can also be a good time to re-pot, as many houseplants will still have a couple of months growing to do before winter.

2) Don’t re-pot your plant unless it actually needs repotting.

When you first buy a houseplant the pot will be fine, but after some time it will become too small. There are some simple signs to look for to see if a plant needs repotting.

Firstly, lift the plant up in its pot and turn it upside down. Can you see any roots poking out of the drainage holes? If you can see roots emerging from the holes then there is a good chance that it needs repotting. If you are not certain, then gently tip the plant out of its pot to inspect the whole root system. If the pot is packed with roots then the plant is ready to be repotted.

Secondly, a plant needs repotting is if it seems to be struggling for space in its pot. Some plants, for example the ZZ-plant (Zamioculcas zamiifolia), will make it obvious when they need repotting as their thick roots and rhizomes will start distorting their pots when they get pot-bound.  While other plants, like the Peace lily, produce a mat of roots on the surface of the soil when they become pot-bound.

Finally, if you have been overly generous with the watering, your plants may need repotting in the same pot but in fresh compost to save them. This is because excess moisture in the compost causes roots to rot. If this is the case you will need to remove any diseased or rotting roots with a sharp knife, and prune back the plant to compensate for the loss of roots.

3) Do use a pot with drainage holes.

Drainage is important for houseplants. Getting the watering right is the key to having healthy, happy houseplants. In my experience, overwatering is the most common cause of poor health and death for pot plants. Using a pot with drainage holes is the easiest way of ensuring your plant doesn’t run the risk of sitting in excess water. Drainage holes allow air to the roots, and they also allow the flushing away of excess salts from the soil. There is another straightforward reason, it is much easier to water a plant with drainage holes.

The traditional way to grow houseplants is to use a pot with drainage holes and sit it on a saucer to catch the excess water. At Capital Gardens we stock a range of plastic plant pots and matching saucers in terracotta, black and green. We also offer bamboo pots by Haxnicks made from sustainable natural materials – these come in sage-green and terracotta, with matching saucers available.

Expert Tip: New terracotta (clay)pots should be thoroughly soaked in clean water before use.

To crock or not to crock? Traditionally a layer made of broken clay pots (crocks) or gravel was placed at the bottom of a pot to improve drainage. This practice is not now recommended because modern compost mixes drain uniformly, and the crocks just raise the pot water-table nearer to the roots.

https://www.bbc.co.uk/news/blogs-magazine-monitor-27126160

Pots Without Drainage.

So, you’ve seen a beautiful pot on our shelves, but it has no drainage. Do you just forget it and go for a plain pot with drainage holes?

The one thing I always tell houseplant customers is never to plant directly into a cover pot. “Can I plant it directly into this cover pot?” is one of the most asked questions I get working with houseplants. I always say, “I don’t recommend it”. Or just, “No!”. Or even, “No! not even with a thick layer of gravel at the bottom.” – and yes, you know who you are!

Relax. This doesn’t mean you can’t buy that beautiful cover pot that will fit so well with your new décor – just keep the plant in its plain pot! In other words, keep your plant in its plastic pot and use the decorative pot as a cover. Then you can simply lift the plant out for its watering and place it back when you’ve finished.

Expert Tip: Don’t buy a cover pot that only just fits. Pick a larger size that makes is easy to lift the plant in and out. This also means that you will be able to re-pot the plant into a larger plastic pot as it grows and use the same cover pot to display it in.

4) Do choose an appropriately sized pot. Use a clean pot that is one or two sizes larger than the original. Do not be tempted to over-pot. In other words, don’t move the plant into a pot that is significantly larger than the one it already is in. This is because over-potted plants are at risk of root-rot due to excess moisture retention by the extra volume of compost.

5) Do use a suitable, fresh potting compost. As already discussed, use fresh houseplant compost when you are repotting. General houseplant repotting compost is appropriate for most houseplants.

However, some plants groups require specialist composts. What might be a good compost for one plant may not be suitable for another. For example:

1. a) Cacti and succulents. These need a free draining potting mix such as Westland Cacti and Succulent Potting Mix or Cactus & Succulent Focus Repotting Mix.

Expert Tip: I add about a third of horticultural grit to cacti and succulent potting mixes and blend it in well. This sharpens the drainage and adds weight to the mixture.

1. b) Orchids. Only re-pot orchids if they are beginning to climb out of the pot, or if their roots look like they are beginning to rot. Commercially grown orchids are usually started on a plug of compressed coir (coconut fibre) which should be removed when you are repotting. Always use a proprietary orchid mix such as Orchid Focus Repotting Mix or Westland Orchid Potting Mix. Orchids such as the moth orchid (Phalaenopsis) should be repotted in a clear plastic pot because the roots are attracted towards the light. Moth orchids can be repotted at any time of the year when they need it.

To learn more about repotting moth orchids visit:

https://www.rhs.org.uk/advice/profile?pid=388

1. c) Citrus plants. Using a specialist loam (soil) based compost that provides the optimum nutrients will result in a healthier citrus plant. A loam based compost helps retain nutrients essential for fruit formation. Westland produce a specialist Citrus Potting Mix.
2. d) Carnivorous plants. Insect-eating plants grow best in a low nutrient ericaceous (acidic) potting medium. Carnivorous Focus Potting Mix is suitable for these plants.

To learn more about growing carnivorous plants, visit:

https://www.gardenersworld.com/plants/10-tips-for-growing-carnivorous-plants/

Top Tip: If you need advice about a finding the right compost for repotting a specific plant our Houseplants Experts can advise you and suggest an appropriate mix.

6 Steps To Successfully Re-Pot A Houseplant.

1) Gather together all the things you will need before you start. This will include the correct potting mix and a new pot of the appropriate size (with drainage holes). You will need somewhere to work where you can make a mess and clear it up. In warm weather it is easier to take your houseplants outdoors for repotting. Other items useful to have include a pair of gardening gloves and a hand trowel for scooping compost.

2) Water the plant 24 hours before you re-pot it. It is easier to get a plant out of its pot and keep the root-ball intact during repotting if you do this.

3) Once you have taken the plant out of its pot use the opportunity to look at the roots in case there are pests such as root mealybugs: https://www.rhs.org.uk/advice/profile?pid=201

If you discover any problems with the roots then treat them before proceeding with repotting.

4) Fill the quarter bottom of the new pot with fresh potting compost. Place the root-ball of the plant on top of this layer. Ideally, you want the soil line to be 2 to 3cm below the top of the new pot, so that when watering your plant, the water will stay in the pot and won’t simply run-off.

5) Fill the pot around the edges until the plant is sitting at the same level as it was at in the original pot.

6) Do not press the soil down. A light tapping of the pot on hard surface is sufficient to settle the compost. I wait a few of days before I first water a repotted plant. This is because the plant has already been soaked to get it out of the old pot, and it gives any damaged roots the chance to heal, reducing the risk of rot. After the first watering the compost might sink in a few areas. These areas can be filled with some more compost.

Expert Tip: When repotting a plant growing up a moss pole don’t be tempted to untangle the plant from its pole and reattach it to a longer pole. Simple purchase a moss pole extension section and connect the two together after you have repotted the plant.  Alternatively, you can add a taller moss pole behind the shorter original pole.

To learn more about choosing and growing indoor climbing plants:

https://www.capitalgardens.co.uk/blog/social-climbers/

Plants with aerial roots such as Monstera, moth orchids and Anthurium need special attention. These special roots appear above the surface of the soil and should not be cut off nor buried in the soil when repotting.

More Thoughts On Repotting.

If your houseplant is very slow growing, or you don’t want it to grow much bigger then you can re-pot it back into its pot using some fresh compost after brushing some of the old soil from the root-ball.

If you have a large houseplant in a massive pot then you may no longer have the strength or space to move it up to a bigger pot. Instead, you can refresh the compost at the top of the pot every one to two years. To do this simply break up the surface soil using a hand fork and remove as much of the soil as possible. Then top it back up with fresh compost.

Knowing which plants need specific composts opens up the possibility of creating indoor gardens. Planting up groups of plants that need the same soil and conditions gives you the opportunity to be creative. For example, you could design a desert landscape with cacti and succulents, or a mini-swamp with carnivorous plants.

In Conclusion.

For most people spending time caring for houseplants is pleasurable. If you dread repotting, then think of it as a chance to give your plant a health check as well as basic maintenance, and you will find you will become confident with the needs of your individual plants and how to get them to truly flourish.

Repotting should only be done when a plant needs it, that is when the plant has out-grown the pot. Don’t be tempted to over-pot, because moving a plant into a much larger pot may cause more harm than good. Remember, plant pots should have drainage holes and cover-pots (cachepots) are used for aesthetic reasons. Choosing a nice cover-pot is a great way to freshen the appearance of a houseplant and add texture and colour to a room.

There is no secret to repotting. All you need to do is to provide the plant with an appropriately sized pot with drainage holes and the correct potting mix. So why not take a closer look at your houseplants and see if any would benefit from repotting and a tidy up?