UK compost
What compost for giant reed grass in the UK?
Arundo donax
More about giant reed grass in the UK
Which compost giant reed grass needs
For giant reed grass the mix to buy is peat-free ericaceous (lime-free) compost. One of the most adaptable plants available, growing in nearly any soil type from light sands to dense clay and heavy wet soils. In heavier soils its root and rhizome spread is somewhat restricted, which can be advantageous for containment. Incorporate organic matter at planting for fastest establishment.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 giant reed grass 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?
giant reed grass is a lime-hater: it needs an acidic, lime-free ericaceous compost. In ordinary (limey) multipurpose it slowly yellows between the leaf veins as it locks out iron. Buy a bag labelled "ericaceous", and in a hard-water area water with rainwater where you can, since tap water is slightly alkaline.
For the full recipe, pH and drainage detail (US wording), see the giant reed grass soil & potting-mix guide.
Compost for giant reed grass in the UK — frequently asked questions
What compost should I use for giant reed grass in the UK?
Use peat-free ericaceous (lime-free) compost. One of the most adaptable plants available, growing in nearly any soil type from light sands to dense clay and heavy wet soils. In heavier soils its root and rhizome spread is somewhat restricted, which can be advantageous for containment. Incorporate organic matter at planting for fastest establishment. 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 giant reed grass?
No — giant reed grass needs an acidic, lime-free (ericaceous) compost. Standard multipurpose is too limey and will slowly cause yellowing between the leaf veins (lime-induced chlorosis). Buy a bag labelled "ericaceous".
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 giant reed grass perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does giant reed grass 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 giant reed grass need?
Always a pot with drainage holes. Highly adaptable — any moderately fertile soil from light sand to heavy clay; pH 5.5–8.5. 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 giant reed grass care
See the full giant reed grass care guide, its UK watering and UK hardiness.