For peat’s sake! Time to dabble with compost alternatives this summer

We must learn how to garden without peat. Climate change and previous environmental damage mean that what remains of the world’s peat reserves is thought better left untouched.

Undisturbed peatlands hold and store massive quantities of fossil carbon. To protect this land, sales of peat-based composts will be banned in the UK from 2024.

So if, like many, you use peatbased potting compost in your garden, you will have to begin searching for an alternative.

For more than a century, sphagnum peat moss has played a crucial role in horticulture. Peat mops up and holds surplus water, allowing it to drain away.

In a pot, that helps to maintain the vital balance of moisture and air within the constituents of the potting composts.

Peat-free composts are much less versatile. However well formulated, they lack that unique ‘blotting paper’ quality.

When waterlogged, they can damage roots. If allowed to dry out, they’re quick to cause drought stress and can be difficult to re-moisten.

So peat-free gardening may seem daunting at first. But once you understand how these composts behave, your results can be just as good.

PLENTY OF CHOICE

Alternative composts have been used successfully for decades. The late TV gardener Geoff Hamilton went peat-free 30 years ago. Today, his son Nick owns and runs the fantastic Barnsdale Gardens and nursery organically and without peat.

Peat substitutes for growing media include wood fibre, coir (coconut fibre), composted bark, treated garden waste and even wool. Non-organic additives include mineral plant fertilisers plus sand or coarse grit, for better drainage.

In some peat-free products, rockwool or perlite are added to improve moisture retention and sustain root development. You can also add water-retaining gels to composts. These hold water, reducing the rate at which the growing medium dries.

It’s worth selecting high-quality peat-free composts, which are more likely to contain moisture controllers. But if totally new to growing peat-free, you’d be wise to try several products before settling on one.

As with all growing media, used potting compost has value. Save the old growing medium for mixing into new garden compost. If you don’t make compost from garden waste, you should – it’s free soil conditioner. 

SHOCK OF THE NEW

The change to peat-free may seem taxing. When you open your first bag, it might feel lumpy and need breaking down. Some products smell peculiar, too. And wood fragments or chunks of bark could be visible.

I’m currently planting summer pots with two options Miracle- Gro Premium All Purpose Compost and Levington Peat Free. Containing coir and composted bark, they’re both dark-looking and pleasant to handle.

Despite being made from byproducts, composts are pricey whether peat-free or not. But you’re likely to find it worth paying extra for premium products.

You may see ‘With Added John Innes’ printed on some bags. This is the name for specific recipes, developed in 1938 at what was then called the John Innes Horticultural Institution. All J. I. recipes contain loam, sand and, er, peat. So peat-free they ain’t.