A 5kg coir brick is surprisingly compact. Put one beside a large bag of conventional growing medium and it can be difficult to imagine that, with the addition of water, the brick will expand to many times its original size.

It is one of the reasons compressed coir has proved so practical for gardeners. It is easy to store, straightforward to handle and can provide a substantial quantity of growing medium when required.

But it also raises an important question:

How much does a 5kg coir brick actually make?

The answer isn’t quite as simple as the number printed on the packaging.

How many litres does a 5kg coir brick make?

Depending on the product and the way it is hydrated and prepared, a 5kg compressed coir brick can produce a considerable volume of growing medium.

Our CoirProducts® Coir Vital Grow® 5kg Coir Potting Mix is marketed as producing approximately 80 litres when fully expanded and prepared.

There is an important distinction here.

5kg is the weight of the compressed brick. Litres describe the approximate volume of the material once it has been hydrated and expanded.

Understanding that difference makes comparing compressed growing media considerably easier.

Why can expanded volume differ?

Coir is a natural material, and the final volume isn’t determined by weight alone.

How much water is added, how long the brick is allowed to hydrate and how thoroughly the material is loosened can all influence its final volume.

A partially hydrated brick may still contain dense, compressed sections. Equally, freshly expanded coir that has been properly loosened will naturally occupy more space than material that has been pressed firmly into a measuring container.

Particle structure, compression and the moisture already present in the brick can also make a difference.

This is why litre figures should be understood as an approximate expanded volume rather than an absolute measurement in every set of conditions.

How should you hydrate a 5kg coir brick?

Place the brick in a large container, wheelbarrow or other suitable growing area and add clean water gradually.

Allow the brick time to absorb the water rather than attempting to saturate it immediately. As the outer layers begin to soften and expand, gently loosen the material.

Continue adding water as necessary until the compressed sections have opened and the coir has developed an even, loose texture.

The finished material should be moist and workable rather than unnecessarily saturated.

It is a remarkably satisfying transformation — what began as a dense 5kg brick becomes a generous quantity of material ready for growing.

Should you compare coir by weight or litres?

Both are useful, but neither should be considered in isolation.

Weight tells you how much compressed material you are purchasing. Expanded litres give you a practical indication of the quantity available after preparation.

But there are other questions worth asking before choosing a coir growing medium.

Consider what the product has been designed for, whether nutrition has been incorporated, what you intend to grow and whether the growing medium suits that particular use.

The largest litre figure isn’t necessarily the most useful way to judge which product is right for your plants.

Good gardening is rarely about a number alone.

Compact to store, ready when you need it

One of the great practical advantages of compressed coir is that you don’t have to store the equivalent volume in large, cumbersome bags.

A compressed brick can sit neatly in a shed, greenhouse or garage until it is needed. Hydrate it when you’re ready to plant, loosen the material and use what you require.

For gardeners working with smaller gardens, allotments, greenhouses, patios or limited storage, that convenience can make a considerable difference.

Over 11 years of coir experience in the UK

Coir isn’t a recent addition to our shelves.

CoirProducts® has been supplying coir growing products to gardeners across the UK for over 11 years.

During that time, we’ve watched coir become increasingly familiar in British gardens, allotments, greenhouses and homes. For us, however, it has never simply been another growing medium added to a large gardening catalogue.

Coir is what we specialise in.

That experience influences not only the products we offer, but the advice we give alongside them. We believe gardeners should understand what they’re buying, how to prepare it and what they can reasonably expect once the brick is hydrated.

Whether you’re opening your first compressed coir brick or have been growing with coir for years, our aim remains much the same: to provide dependable coir growing products backed by practical knowledge and experience.

More than eleven years on, we’re continuing to develop our range and help gardeners across the UK make better use of this remarkably versatile growing material.

So, how much does a 5kg coir brick make?

Our 5kg Coir Vital Grow® Coir Potting Mix produces approximately 80 litres when fully expanded and prepared.

The precise volume you see at home can vary according to hydration and how the expanded material is loosened and measured, which is why understanding the preparation process is just as important as reading the litre figure.

Perhaps that is the real appeal of compressed coir: a remarkably small brick, a surprisingly generous amount of growing medium, and considerably less space required in the shed.

And after more than 11 years specialising in coir products in the UK, that’s a transformation we still rather enjoy watching.