The Best Peat-Free Compost for Houseplants in the UK

The 2024 retail peat ban was a quiet but important shift in UK horticulture. Peat extraction from upland bogs has devastated some of the most carbon-rich landscapes in Britain — and the ban accelerated a long-overdue transition. The trouble is that not all “peat-free” composts are equal. Most that landed on supermarket shelves through 2023–24 were thin, fast-degrading composts based on coir, green waste, and wood fibre. They compact, lose structure within months, and starve aroids of the air their roots actually need.

The composts below are the ones that work. They’ve been tested on a mixed houseplant collection (Monstera, Calathea, Philodendron, Pothos, succulents, ferns) across a full UK growing season, and ranked by what each is best at.

Best Overall — Dalefoot Wool Compost

The Dalefoot Wool Compost is the exception to the standard peat-free disappointment. Made in the Lake District from upland sheep’s wool and bracken — two waste streams from Cumbrian fell agriculture — it produces a substrate that’s genuinely circular: agricultural waste becoming horticultural input.

What matters in the pot: the wool is the structural innovation. Sheep’s wool holds roughly 30% of its weight in water without becoming saturated, giving the substrate a moisture-retention curve closer to leaf litter than peat. It holds water available to roots but releases it gradually. Plants in Dalefoot needed watering roughly every 10 days vs every 7 days in the supermarket peat-free control — same plants, same room, same window.

The wool also keeps the substrate from compacting. Six months in, the Dalefoot mix still has visible air pockets and crumb structure where the control had compressed to a dense paste. And as the wool breaks down it releases nitrogen slowly — a plant potted in Dalefoot gets a months-long mild feed without supplemental fertiliser.

The price is the friction: roughly £10 per 15L bag, about double the supermarket peat-free. The case for the spend: the substrate lasts longer in the pot (fewer repots over the plant’s life), and the built-in slow feed reduces or removes the need for liquid fertiliser. Over a plant’s lifecycle, the cost difference largely closes. Full review: Dalefoot Wool Compost.

Best for Aroids — Soil Ninja Premium Aroid Mix

Aroids — Monstera, Philodendron, Anthurium, Pothos — want something specific that no general-purpose compost delivers: a chunky, airy substrate where roots can breathe between waterings. The right mix is roughly 40% bark, 30% perlite, 20% coir, 10% worm castings. You can mix it yourself, or you can buy it pre-blended from Soil Ninja.

Soil Ninja’s aroid mix is the most-reached-for pre-blended specialist substrate in UK houseplant culture, and the reasons hold up under testing. Six months in a Monstera repotted into Soil Ninja: visible new aerial roots, two new fenestrated leaves through the winter, none of the compaction we’ve seen on supermarket multi-purpose mixes. The drainage is fast enough that you can water more frequently without inducing root rot — the chunky structure pulls in air with every flush.

The price is £12–£18 per 10L, which is a meaningful premium over making your own mix. The honest case for buying pre-blended is convenience: if you’ve got 5 Monsteras to repot in spring, the time savings vs measuring perlite and bark by volume might be worth the markup. If you’re repotting one or two plants, mix your own (see DIY pick below).

Best Supermarket Default — SylvaGrow Multi-Purpose Peat-Free

The honest budget pick. SylvaGrow is made by Melcourt, RHS-approved, available at Wilko, B&Q, and most independent garden centres at £5–£7 per 50L. It’s not as structurally stable as Dalefoot or as plant-specific as Soil Ninja, but it’s a proper peat-free that won’t actively harm most houseplants.

The structure compacts faster than Dalefoot — by 6 months in the pot you’ll notice the surface has compressed and water is starting to channel. Plan to repot annually for plants in SylvaGrow, vs every 2 years for plants in Dalefoot. But the per-bag cost difference (roughly 4× cheaper) more than covers the extra repot.

This is the right compost for a starter plant collection where the cost of upgrading to Dalefoot or Soil Ninja across 20+ pots is genuinely off-putting. It’s also the right base for the DIY custom mix below.

Best Cactus & Succulent — Melcourt Cactus & Succulent Mix

Succulents and cacti want the opposite of what aroids want: very fast drainage, low organic content, very low moisture retention. A standard compost — even a peat-free one — kills them by holding water around their roots.

Melcourt’s Cactus & Succulent Mix is the peat-free standard for arid-zone plants. Gritty texture, high sand and perlite content, low organic. We tested it on a mixed collection of Aloe, Jade, Echeveria, and String of Pearls across 6 months; none of the soft-stem-collapse symptoms that root rot produces, even with conservative watering through a damp UK autumn.

If you can’t find Melcourt locally, equivalent options exist (B&Q’s own-brand cactus mix is genuinely fine; Aldi sometimes carries a peat-free succulent mix in spring at lower cost). The thing that matters is the grit content — over 50% mineral material. If a “cactus mix” looks dark and peaty when you open the bag, return it.

DIY Custom Mix — Base + Perlite + Bark

For experienced repotters and larger collections, the cheapest route to a high-quality aroid substrate is to make your own. The recipe:

• 2 parts peat-free multi-purpose compost (SylvaGrow or similar) — £6 per 50L
• 1 part horticultural perlite — £5 per 5L bag
• 1 part orchid bark (composted pine bark, medium grade) — £7 per 5L bag
• Optional: a handful of worm castings for slow-release nitrogen — £4 per 1L

Mixed: roughly 30 litres of high-quality aroid substrate for ~£15. About half the cost of buying Soil Ninja pre-blended, and arguably better because you can adjust the ratios per species (more perlite for hoyas, more bark for orchids, more coir for ferns).

The trade-off is time and storage. You need somewhere to mix the bag of substrate (a deep mixing tray, an empty plant pot, a balcony floor with a sheet), and you need the individual components on hand. For 1-2 repots a year, just buy the pre-blended. For 10+ repots a year, mix your own. The potting mix guide covers the ratios in more detail.

What to skip

“Peat-free” composts at suspiciously low prices. Some big-box brands relabelled their existing coir-and-wood-fibre composts as “peat-free” after the ban without changing the formulation. The structure is poor, the substrate compacts within months, and you’ll repot more often. Check reviews before buying anything not from Melcourt (SylvaGrow), Dalefoot, or Soil Ninja.

Generic “houseplant compost” sold in 5-litre branded bags at premium prices. Often the same SylvaGrow base in fancy packaging at 3× the per-litre cost. Buy SylvaGrow direct.

Adding “houseplant feed” to fix a poor substrate. If your compost is compacting and holding water poorly, more nitrogen won’t help — the problem is structural, not nutritional. Repot into a proper aerated mix.

How we tested

Each compost was used as the sole substrate for at least three plants over a full UK growing season (March–September). Tests measured visible plant growth, watering frequency required, substrate structural integrity at 3 and 6 months, and direct comparison to a SylvaGrow control. See how we review.

For the underlying soil biology and why aerated substrate matters, see the houseplant science hub. For mix ratios by species, see the potting mix guide.