Are all peat-free composts the same?

Melcourt’s Technical Director, Catherine Dawson, answers, “are all peat-free composts the same?

Changing from a well-loved compost that you have used for years can feel challenging. The news that all sales of peat in composts sold to gardeners will be banned from 2024 is excellent for habitat conservation and climate change, but some gardeners who are yet to make the switch to peat-free are feeling nervous. It can leave us wondering are all peat-free composts the same.


In this month’s blog, we answer some common questions about using peat-free compost, and we will demonstrate that it doesn’t have to feel like a leap into the unknown.


As manufacturers, the challenge has been to design and supply a growing medium – a compost – that is as easy to use as peat and as successful in its performance across a wide range of applications. When SylvaGrow® was launched in 2014, we based the formula on our professional peat-free range Sylvamix®, which had already been used by commercial growers for well over the previous decade. Growers have been using Sylvamix for everything from seed sowing to tree growing. We strongly believe that gardeners deserve products that are every bit as effective as those used by professionals.


So, what, if any, are the differences between a peat-based and a peat-free medium when used in the garden? Here we answer some common questions.


Will Peat-free compost need more watering?

SylvaGrow has been designed to be as easy to use as peat. It does not require more water in total than peat. For many applications, you are unlikely to notice any difference in the amount of water it holds. However, do remember that all composts have a maximum water-holding capacity. Adding more once a compost is at capacity is a bit like trying to add more water to an already full jug – which you wouldn’t even attempt as it is obvious the jug is full. So, adding more water once the compost is at capacity causes excess water to run through the mix, leaching nutrients as it goes.


One helpful tip with SylvaGrow – without causing the excessive run-through mentioned above – is to ensure that the compost is well-watered at the outset. This will ensure that subsequent watering is more effective than if dry patches are allowed to remain. Always avoid letting any compost become so dry that the plants are wilting – but as this can occasionally happen to the best of us, a good tip, in this case, is to add a few drops of washing-up liquid to the watering can. This will help to reduce the surface tension and enable the water to be retained more easily.


If your application is particularly water-loving, such as summer hanging baskets, we recommend SylvaGrow Tub and Basket with its extra moisture-holding capacity.


The compost surface looks dry, but there seems to be enough moisture underneath.

Be aware that the surface of SylvaGrow can look dry when in fact, there is adequate moisture underneath. Managing this comes down to knowing your compost. We recommend checking using the weight of the pot or by the ‘finger test’ – simply pushing a finger into the layers below the surface to check the moisture content.


Will I have to feed more frequently with peat-free compost?

This shouldn’t be necessary with a well-designed compost. All compost ingredients, including peat, have the capacity to resist leaching, but the extent varies with the material. Peat is relatively good at resisting leaching, as are the composted bark and wood fibre used in SylvaGrow. Some gardeners like compost with added loam because soils are typically very good at resisting leaching.


At manufacture, fertilisers are added to SylvaGrow in various forms, the part immediately available to the plant and the part more slowly available. Nevertheless, in common with most composts, including peat-based ones, it requires supplementary feeding after the first 4 to 6 weeks depending on the application. A leading head gardener once said that one of the most significant differences he had noted over the years between a professional and an amateur gardener was their use of supplementary feed – professional gardeners being more likely to use more.



Are there any other differences I should be aware of?

The best advice with peat-free composts is to use a well-researched, tried, and tested brand such as SylvaGrow. All composts, including peat, will be higher in price next season but don’t be tempted to buy on price alone. There is a reason why some composts are more expensive than others. It costs money to carry out the thorough R&D, trials and development work and constant quality monitoring that goes into an excellent growing medium.


Always check the age of the stock you are buying.

Fresh compost is always best, whatever it is made from. SylvaGrow carries the date of manufacture on the side of the pack – try to use it within a year of that date. And remember that in one bag of compost, there is enormous potential – the number of seedlings you can raise, cuttings you can root and pots you can fill with just one bag is immense, giving months of joyful growing!


We are always pleased to answer any specific questions you may have that aren’t covered in this article – do get in touch. And do share your SylvaGrow success stories!