Composting

The UK’s Best Multi-Purpose Composts For Growing

many bags of compost
Written by April Foot

Multi-purpose compost is an easy-to-use, versatile compost that can be used to grow a wide variety of plants.

This type of compost is usually a blend of peat, lime and fertiliser, as well as other materials, such as bark. It contains a good balance of nutrients, which are suitable for many species. The best multi-purpose composts have a fine, crumbly texture, which helps to retain moisture.

Multi-purpose compost makes a good, all-round option for gardeners who are growing a range of plants, flowers, fruits and veggies. It is also ideal for many houseplants, and those grown in pots and containers, so you don’t need outside space to put this compost to good use.

To help you select the best multi-purpose compost for your needs, we’ve rounded up 5 of our favourite options on the market today.

Our #1 Top Pick
Ambassador Multi Purpose Compost 10L
Value Pick
J Arthur Bowers Multi Purpose Compost 100L Bale
Also Consider...
Westland Multipurpose Compost with Added John Innes, 10 L
SIze
10L
100L
10L
Nutrient Provision
4-6 Weeks
6 Weeks
5 Weeks
Weight
3.46Kg
23.1Kg
4.1Kg
Price
£7.99
£16.33
£4.49
Our #1 Top Pick
Ambassador Multi Purpose Compost 10L
SIze
10L
Nutrient Provision
4-6 Weeks
Weight
3.46Kg
Price
£7.99
Value Pick
J Arthur Bowers Multi Purpose Compost 100L Bale
SIze
100L
Nutrient Provision
6 Weeks
Weight
23.1Kg
Price
£16.33
Also Consider...
Westland Multipurpose Compost with Added John Innes, 10 L
SIze
10L
Nutrient Provision
5 Weeks
Weight
4.1Kg
Price
£4.49

Last update on 2020-08-14 / Affiliate links / Images / Pricing from Amazon Product Advertising API

These composts are nutrient-rich, affordable and will help your plants grow big, strong and green.

Best Pick: Ambassador 10L Multi Purpose Compost

Our best multi-purpose compost is lightweight, affordable, and packed with the essential nutrients and trace elements needed to grow healthy plants

Topping our list of the best multi-purpose composts is this Ambassador 10L Multi-Purpose Compost, which is ideal for sowing and potting many common house and garden plants.

It’s a complete compost which contains all the essential trace elements your plants need, and will feed them for 4 – 6 weeks. You can plant directly into this compost, as it doesn’t need to be mixed with soil before use, and it retains moisture well.

The small 10 litre size of this compost bag is ideal for those with limited storage space, or who just require a small amount of compost for potted houseplants. The bag is lightweight and easy to lift, so you won’t struggle to fill your containers. 

However, the compact size means there is less compost than in some competitor’s products of a similar price. If you have a lot of plants to pot, or you want some compost leftover for repotting, you may need to purchase more than one bag.

That’s really the only negative we can find with this one though – it’s a comprehensive and nutritious compost, that is suitable for many different types of plants, for a great price.

Pros

  • Ideal for potting, sowing and cuttings.
  • Contains all essential trace elements.
  • Will feed plants for 4 – 6 weeks.
  • Suitable for a wide variety of plants, including potted houseplants.
  • Small bag is easy to lift, transport and store.
  • Retains moisture well.
  • Low-priced and affordable.

Cons

  • Only contains 10L, so you might need more than one bag, depending on how much you’re growing.
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Value Pick: J Arthur Bowers 100L Value Bag

Our best value multi-purpose compost offers a huge 100L of compost, for an incredibly low price

If you’re looking for a better value compost, this J Arthur Bowers 100L Value Bag offers a whopping 10x the amount of compost as our top pick, for only around 2x the price.

This nutrient-rich compost is suitable for a wide variety of plants, including shrubs, flowers, vegetables and house plants. It has a slightly coarse texture, which is perfect for promoting root growth, and can be used straight from the bag. You could also mix in some sand, to improve drainage if required.

The compost contains nitrogen, phosphate and potassium – all essential for plant growth – as well as trace elements, which can help with disease resistance. It can feed growing plants for the first 4 – 6 weeks, after which you will need to add plant food every 1 – 2 weeks.

The best thing about this option is the amount of compost you get for your money – 100L should go a long way, and will be a better choice for you if you have a lot of plants. However, be aware that 100L of compost is pretty heavy, and you might struggle to move the bag around.

This is our lowest-priced multi-purpose compost per litre, and offers excellent value, without compromising on nutrients. For users with larger gardens, or a house full of potted plants, we wholeheartedly recommend it.

Pros

  • Suitable for a wide variety of plants.
  • Feeds plants for up to 6 weeks.
  • Contains nitrogen, phosphate and potassium, as well as trace elements.
  • Reduced peat formula.
  • Sweet-smelling.
  • Large 100L size is perfect for users with lots of plants.
  • Great value – our lowest priced compost per litre.

Cons

  • Large size takes up more storage space.
  • Bag is heavy, and might be difficult for some users to lift and transport.
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Westland Multipurpose Compost

This high-quality compost has added John Innes, and retains moisture and nutrients – but it works out to be the most expensive, per litre

Our next option is this Multi-Purpose Compost from Westland. This compost is suitable for plants at all life stages, and will feed them for up to 5 weeks. It is particularly recommended for hanging baskets, containers, and seedlings.

It has an open structure and a high peat content, which encourages air and water retention, and provides the perfect conditions for germination. However, the high peat level might not be so appealing to those concerned about the environmental impacts of peat bog depletion.

Added John Innes ups the loam content of the compost, and further helps to promote healthy growth and flower formation. Despite retaining moisture, the compost drains easily, so you won’t need to worry about your plants getting waterlogged.

This one comes in a 10 litre bag, which is again easy to transport and store, and the handle in the top of the bag makes it even more user-friendly. However, you are getting less for your money, as this one works out to be our most expensive compost, per litre.

Overall though, this is one of the most nutritious, loamy composts in our selection, and if you want to give your plants the best chance in life and be rewarded with the best fruit and flowers, it might be worth it.

Pros

  • Suitable for plants at all life stages.
  • Feeds plants for up to 5 weeks.
  • Open structure and high peat level encourages air, nutrient and water retention, and provides the perfect conditions for germination.
  • Added John Innes adds more loam to the compost, promoting healthy growth.
  • Ideal for use in hanging baskets and containers.
  • 10L bag is lightweight and easy to transport.

Cons

  • Pricey – this is our most expensive compost, per litre.
  • 10L might not be enough for those with multiple plants.
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Gro-Sure 120L Bag

This huge bag of high-performance compost contains 120 litres, and feeds plants for 4 months – you just might need help lifting it

This Gro-Sure 120L All-Purpose Compost is our largest bag of multi-purpose compost – you might need some help carrying this one to your garden! It does mean that it will last much longer, and you won’t need to re-purchase as often.

To give you an idea of how much is included, the contents of the bag can be used to fill 12 x 28cm pots. This compost is ideal for use in pots, hanging baskets and containers, as well as in beds, borders, and most other places in your garden.

The compost consists of 50% peat, which helps it to retain water, and means it requires up to 50% less watering. The other 50% of the formula is a patented West+ wood fibre, produced sustainably from FSC certified trees, to reduce the overall peat content, and make the compost more eco-friendly. 

The resulting compost is nutritious, encourages root growth, and will provide food for your plants for up to an impressively long 4 months. This is the longest of all our composts, and is great for gardeners who prefer low-maintenance options.

If you want to plant outside, or you have a lot of indoor potted plants that need compost, this large bag should keep you going for a considerable amount of time, and represents excellent value for money.

Pros

  • Patented West+ wood fibre formula, from FSC certified trees.
  • 50% peat ensures good water retention – up to 50% less watering required, compared to other composts.
  • Feeds plants for up to 4 months.
  • Ideal for beds, borders, pots and containers.
  • Long-lasting and good value, considering the amount you get.
  • 50% lighter than standard multi-purpose compost.

Cons

  • Huge 120L bag may be difficult for one person to move around.
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Miracle Gro 50L All-Purpose Enriched Compost

At 50 litres, this all-purpose compost represents a good compromise of quantity, size and price

Our final multi-purpose compost, this 50L option from Miracle Gro, offers a good balance between quantity, and ease of transportation.

This compost includes patented Fibre Smart technology, with 100% natural wood fibres, to provide the optimum balance of air and water. You can use it to grow flowers, fruits and vegetables, as well as house plants, in containers, hanging baskets or beds.

It is capable of feeding your plants for pretty much the whole growing season, up to 3 months. This is one of the longest on our list, and will help you to save on plant food in the initial growing period.

The manufacturer also claims that it contains 40% more nutrients than most multi-purpose composts, and will grow plants twice as big as when using ordinary garden soil – so it’s ideal if you’re aiming for prize-winning pumpkins!

Some users report receiving compost with large twigs and pieces of wood in it, which need to be sieved out before use. Ultimately though, this compost is a great compromise for those who want a good quantity of compost, without spending loads, and in a bag that’s easy to store and move around.

Pros

  • Ideal for growing plants, fruits and vegetables.
  • Suitable for use in pots, containers, hanging baskets, beds or borders.
  • Enriched with 40% more nutrients than standard multi-purpose compost.
  • Provides optimum balance of air and water, thanks to the patented Fibre Smart technology, with 100% natural wood fibres.
  • Feeds plants for the whole season, up to 6 months.
  • Grows plants twice as big as when using ordinary garden soil.

Cons

  • May contain twigs and pieces of wood, which need to be sieved out.
  • Some users report problems with fungus and gnats.

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How To Use Multi-Purpose Compost

You can use multi-purpose compost for a variety of purposes, from planting out seeds, to repotting established plants.

To sow seeds in multi-purpose compost, first sieve the compost to remove any large, coarse material. Fill the seed tray with compost, water and allow it to drain. Sow the seeds, and cover with more compost. Store the tray in the necessary conditions for germination.

To pot seedlings, fill a tray with multi-purpose compost, and make small holes for planting the seedlings. Press the compost around the bases to firm, and water if necessary.

To re-pot a plant, choose a large enough container, and half fill it with multi-purpose compost. Gently remove the plant from its existing pot, taking care not to damage the root ball. Place in the new container, and fill it in with more compost. Press to firm, and water well.

Can I Use Multi-Purpose Compost For Azaleas?

Azaleas require an acidic compost with a pH of between 5.0 and 6.0, and no lime. The best choice for this is ericaceous compost, which has a high loam content and low amount of peat, so will hang onto nutrients.

Before using multi-purpose compost for azaleas, check the pH level. Some may not be acidic enough for azaleas to thrive, whilst others may be ok. For example, the Westland Multi-Purpose Compost has a suitable pH, and also a high loam content, thanks to the added John Innes.

Should I Use Peat-Free Compost?

Many multi-purpose composts contain peat, as it helps to retain nutrients and water, and provides one of the best fuels for plants. However, peat bogs are a limited resource, and they store a lot of carbon, which is released back into the environment when the peat is removed. Some gardeners are therefore choosing to use peat-free compost, to avoid participating in peat bog depletion. Peat-free composts tend to be more expensive than those which contain peat, but if you’re willing to spend a little more, they’re usually the more eco-friendly option.

About the author

April Foot

April is a freelance writer who specialises in travel, home and garden design, and the environment. She is an avid wildlife-enthusiast and adventure-seeker, and feels happiest when in the Great Outdoors.

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