When your indoor plants are looking for a little worse for wear – and you’ve tried everything under the sun to get them back to their former glory, you can give your leaf babies a new lease on life with potting compost. We’ve got everything you need in your tool kit for repotting as well as ensuring which potting compost and soil you need to repot plants expertly in your best planters and pots.
When looking at our guide, it’s tempting to simply make a decision based on price. However, Geoff Hodge, a contributor for Garden Answers, recommends making “a more informed decision". Make sure to read through our guides as thoroughly as you can. We’ve listed different types of potting compost with different ingredients from a variety of brands at various price points.
Best potting compost at a glance:
• Best potting compost for houseplants: Miracle-Gro, Premium Houseplant Potting Mix Compost - View on Amazon UK
• Best potting compost for succulents: Miracle-Gro, Premium Cactus Succulent and Bonsai Compost - View on ebay
• Best potting compost for hanging flower baskets: Westland, Container Compost Peat-Free - View on B&Q
Geoff recommends experimenting with a couple of different brands to see which compost works best, adding, “It’s only by experimenting that you can discover how each compost ‘works’ – how quickly it dries out, how much water to give, how much fertiliser to add and how often.” You won't need to add much (if any) fertiliser to potting compost, though.
Finally, he adds, “Always buy fresh compost each year. If old compost goes off, it can affect seeds, seedlings and young plants.” We've shared the best potting soils and compost to buy, but scroll down to find out more information on what exactly to look for.
Best potting compost, soil and mix for houseplants
Best potting compost for houseplants
This potting mix from Miracle-Gro encourages optimum root growth for strong, healthy plants on your windowsill. With Fibre Smart providing that air and water balance, your houseplant is going to be well looked after. The bag comes packed with plenty of health and safety advice, useful tips and storage instructions - even some basic instructions. Plus, it contains three months of feed.
Customer review: “Just the right size for a medium planter. Now have happy pepper plants growing. They were visibly looking good after a very short time. I have used Miracle-Gro products for 3 years now and there is no comparison. If you want spectacular plants, fruit and flowers, it's the best."
Pros
- Mostly all-purpose
- Bag is recyclable - check locally
Cons
- Some customers have had gnat infestations after repotting
- Child and pet-friendly
- Water + Fibre Smart Technology
- Suitable for: Seedlings, Cuttings, Herbs, Houseplants and Patio Pots
Best potting compost for bonsai
Bonsai are fascinating interesting plants to have in your home. They portray nature in miniature.
From Westland, this is a specialist blend that can be used by anybody who wants a strong and healthier plant that is provided with optimum water and nutrient availability. Plus, the added Seramis granules do a fantastic job at regulating the plants’ water intake to ensure optimum water and nutrient availability. The added wood fibre improves aeration, drainage and water management. During spring and summer, Westland recommends giving your plant Bonsai Feed every two weeks.
Customer review: "Now planted all my bonsai with this soil and they seem very happy - as I was beginning to lose them. I would recommend this soil for them."
Pros
- A perfect blend for all bonsai
- Seramis granules added for nutrients
- Added wood fibres for improved functions
Cons
- This will supply nutrients for a few months
- Suitable for: Most bonsai plants
Best potting compost for succulents
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This premium Cactus, Succulent and Bonsai Compost from Miracle-Gro is perfect for all types. This potting mix contains a unique combination of 14 vital minerals and a well-balanced pH level for optimum growth and glossy leaves. Plus, it's mixed with sand to aerate your favourite cacti and succulents.
Customer review: "A bit more expensive than a previous one I bought but the only one available at the time. Seems of good quality. Succulents seem happy."
Pros
- pH balanced to improve the environment
- Plant specialised for optimal growth
Cons
- Arrives very wet
- Contains a unique combination of 14 Vital Minerals
- Contains a special sand mix that improves drainage
- Suitable for: Cactus, succulents, bonsai trees, alpine plants and African Violets
Best potting compost for citrus
This Westland Citrus Potting Compost Mix contains loam to retain nutrients and for fruit development. If you have a citrus tree, you should best pot them in the spring before they start active growth. But, they can be 'potted on' at any time in the summer. Plus, this mix contains Seramis granules for optimum water and nutrient availability.
For best results, feed with Westland Citrus Feed.
Customer review: "Excellent product! My lemons love it! Arrived a day earlier than expected. Would recommend it, and will re-order again. Thanks, Westland and Amazon."
Pros
- Contains loam for fruit development
- Can be potted in the spring or summer
- Added Seramis for water and nutrients
Cons
- Will need topping up with feed
- Suitable for: All potted citrus plants
Best potting compost for bulbs
Want some gorgeous potted flowers? Westland Bulb Planting Compost is perfect for all bulbs, indoor and outdoor. As it contains West+ - a special formula, this compost ensures strong and healthy root growth. Plus, it encourages sustained plant development. You get healthier bulbs and vibrant flowers. What more could you want?
The RHS recommends a high-potassium liquid feed, such as tomato fertiliser in the run-up to flowering.
Customer review: "I used this bulb compost for planting amaryllis bulbs. They are growing well."
Pros
- Contains 'West+' for enhanced performance
- Added grit for free drainage
Cons
- Not suitable for ericaceous (lime-hating) plants
- The perfect balance of essential nutrients and trace elements
- Suitable for: All bulbs, indoor and outdoor
Best potting compost for hanging flower baskets
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This peat-free Container and Basket Planting Mix from Westland has been perfectly blended for season-long flowering. Enriched with water-retaining granules, this potting mix will help protect your hanging baskets from underwatering and will support their journey to thriving. Plus, this mix has six-month, slow-release granules for healthy growth.
Pros
- Great value and quality
- Peat-free and lightweight
- Enriched with water-retaining granules
- With 6-month slow-release granules
Cons
- No customer reviews
- Suitable for: Container or basked-bound flowering plants
Best potting compost for herbs
Amazon/WestlandWestland John Innes 28L Seed Sowing Compost is completely peat-free, designed to promote fast and healthy germination of seeds. It includes a blend of coir, loam and sand for optimal drainage and nutrient retention. This compost is enriched with essential nutrients to support seedlings for the first three weeks of growth. With a neutral to slightly acidic pH level, it provides the ideal environment for seed development. John Innes Seed Compost has a light texture that allows seedlings to emerge easily.
Pros
- Good quality
- Large quantity
Cons
- No reviews
- 100% peat free
- Contains vermiculite for water and nutrient retention
Best potting compost for orchids
Modern Gardens recommends this specialist blend if you're looking for a healthier and more abundant flowering for your beloved orchid. This Westland mix will aid healthy growth and more. The added Seramis granules do a fantastic job at regulating the orchids' water intake to help with water retention and nutrient availability. Plus, the added pine bark helps airflow, drainage and healthier root development.
Westland recommends using feed during the growing season and winter - as well as mist and purified orchid water.
Customer review: "My orchid is growing slowly but surely. Roots are sprouting."
Pros
- A perfect blend of Seramis granules
- Added pine bark for airflow and drainage
Cons
- Nutrients will need topping up with feed
- Available in 4 and 8 L
- Essential nutrients for healthy growth
- Suitable for: All orchid types
FAQs: Repotting compost
How is potting compost different to others?
The main elements of potting compost should contain materials that will ensure "quick, strong root growth, together with phosphate, which promotes good root development".
Is potting mix the same as compost?
No – there are differences between the two.
Compost is utilised to add nutrients and organic materials to the soil, such as nitrogen, to aid growth. To clarify, regular compost is not recommended for potting (or repotting) and works best dug in existing garden soil. This is because compost starves your poor plants of air space and waterlogs them. Plus, there are no fertilisers added to compost.
Potting mix – on the other hand, is made from organic plant-based material. But, how is potting compost made? Well - alongside additional nutrients and a control-released fertiliser, potting mix is supported by a host of organic elements. To create a potting mix, materials such as bark, coir, peat and pumice are added to aid growth.
How much potting compost do I need?
When repotting your houseplant, you essentially need to make sure you have enough compost to do the job. According to Modern Gardens contributor Martin Fish, there is a secret to repotting your houseplants, which is to “pot up gradually in pot size”. Choose a pot a little larger than the original, basically. "Potting up" is not to be confused with other terms "potting off" and "potting on", which involve getting cuttings started in pots.
For example, if a small plant is in a 9cm pot, Martin clarifies that this should be a “maximum 13cm pot”. Hopefully, with this, the larger planter gives your potted friend "enough room to trickle fresh compost around the existing root ball.”
So, if you’re potting (or repotting) a houseplant, remember these steps to add the compost.
1. Add a little compost to the base.
2. Position the plant in the centre and gradually add the compost.
3. Give the pot a tap to settle the compost.
Why do I need to repot houseplants?
In short, repotting plants gives a growing plant's roots more room. As plants get older and bigger, their roots expand. This is so they can suck up enough water and nutrients to feed themselves. If you choose to repot plants in a stylish new pot with fresh new compost, it’ll help to give them a top-up of the essential nutrients.
Experts advise repotting during the spring and summer when plants are at their strongest. Hopefully, repotting your plants will help them out. But please don’t be too disheartened if they don’t thrive. Just topping up the compost could help some plants. And – some potted plants prefer a large indoor plant pot so they can spread themselves out. It’s worth doing research into your plants.
Here are some signs to look out for when a plant needs repotting:
• It has been years since you repotted the plant
• The plant looks unstable (breaking away)
• Roots emerging from the bottom of the pot
• The plant has clearly grown a lot over time
• The soil looks very dry and dusty
Can repotting kill plants?
It’s true repotting can be a little stressful for your potted plants. So, it's vital to make sure the plant you are repotting looks healthy before you repot them. You should check for root rot and inspect its leaves for any yellow. Unfortunately, repotting can "shock" a plant and can even kill or stunt its growth - if it's not given plenty of care and attention.
Though, for some comfort, it is normal for a plant to experience a brief period of shock when repotted. Here, your plant may appear wilted and thirsty. You can help it out by leaving any watering for a week. This is to ensure all of the roots have spread out, got used to the new pot and repaired themselves after moving.
Can I use potting compost for seeds?
Generally, no. Sowing seeds in potting compost won't do well. A potting compost or 'potting mix' has lots of added nutrients, which can be too much for seeds. You can get specific seed compost for getting started and germination, which contains peat for support with nutrient retention.
Can you re-use potting compost?
The answer is, generally, yes. Most compost types may last for several seasons, at least - if your plant is healthy and did not succumb to any diseases or pests. In this case, you need to dispose of diseased soil.
Further, make sure to inspect your compost bag, though. Geoff Hodge explains, "Compost that has been sitting around for several months may have become ‘sour’ due to the build-up of excess nutrients." To ensure you’re using fresh, watch out for sun and water exposure - and keep your compost covered and away somewhere dry.
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Piper Huxley is a Homes, Garden and Wellness Product Writer for Modern Gardens Magazine, an all-rounder. When she’s not writing about houseplants, she’s tending to her own growing collection…