UK compost
What compost for round-leaf calathea in the UK?
Calathea orbifolia
More about round-leaf calathea in the UK
Which compost round-leaf calathea needs
For round-leaf calathea the mix to buy is peat-free multipurpose compost. Blend peat-free potting compost with perlite (2:1 ratio) for moisture retention with adequate aeration. Avoid dense mixes that compact and stay soggy. Slightly acidic pH of 6.0–6.5 is ideal.In British garden centres the bagged growing medium is sold simply as “compost” (multipurpose, ericaceous, or loam-based John Innes), which is a different thing from the rotted garden “compost” you make in a heap — for a pot you want the bagged kind.
Peat-free compost
Buy peat-free. The sale of peat compost to home gardeners is being phased out across the UK, and the RHS recommends peat-free on environmental grounds. A good peat-free multipurpose grows round-leaf calathea perfectly well; the one habit to change is watering — peat-free dries faster at the surface while still moist below, so check by feel a knuckle deep rather than trusting the look of the top.
Ericaceous or multipurpose?
Round-Leaf Calathea is straightforward: an ordinary peat-free multipurpose compost is right. For a big specimen or a pot it will live in for years, mixing in some loam-based John Innes No.2 or No.3 adds weight and holds nutrients longer. Ericaceous compost is not needed unless a plant is specifically a lime-hater.
For the full recipe, pH and drainage detail (US wording), see the round-leaf calathea soil & potting-mix guide.
Compost for Round-Leaf Calathea in the UK — frequently asked questions
What compost should I use for round-leaf calathea in the UK?
Use peat-free multipurpose compost. Blend peat-free potting compost with perlite (2:1 ratio) for moisture retention with adequate aeration. Avoid dense mixes that compact and stay soggy. Slightly acidic pH of 6.0–6.5 is ideal. In UK garden centres this is sold simply as "compost" — the bagged growing medium, not garden-made leaf-mould — so match the description above rather than a brand.
Can I use ordinary multipurpose compost for round-leaf calathea?
Yes. A good peat-free multipurpose compost is exactly right for round-leaf calathea. For a large or long-term pot you can mix in some John Innes No.2 or No.3 (loam-based) for extra weight and staying power.
Should the compost be peat-free?
Yes. Sales of peat compost to home gardeners are being phased out in the UK, and the RHS recommends peat-free for environmental reasons. Modern peat-free multipurpose composts grow round-leaf calathea perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does round-leaf calathea need grit or perlite added?
Not essential, but a couple of handfuls of perlite in the mix improves aeration and guards against overwatering — useful on a cool, damp British windowsill where compost stays wet longer.
What pot and drainage does round-leaf calathea need?
Always a pot with drainage holes. Peat-free, well-draining moisture-retentive potting mix. Stand it on a saucer, empty any water that collects after watering, and never leave the pot sitting in a full outer cover — waterlogged compost in a cool UK room is the commonest cause of root rot.
More round-leaf calathea care
See the full round-leaf calathea care guide, its UK watering and UK hardiness.