Growli

UK compost

What compost for blue lyme grass in the UK?

Leymus arenarius 'Blue Dune'

Free-draining + gritPeat-free

More about blue lyme grass in the UK

Which compost blue lyme grass needs

For blue lyme grass the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Thrives in lean, sandy, sharply drained soils, including coastal sand and saline ground; tolerates a wide pH. Rich, moist soils encourage even more aggressive spreading. 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 blue lyme 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?

Blue Lyme Grass does not want a rich, water-holding compost — it wants sharp drainage. Cut peat-free multipurpose roughly half-and-half with horticultural grit, sharp sand or perlite, and always pot into a container with drainage holes. A "cactus and succulent" bagged mix is a ready-made shortcut.

For the full recipe, pH and drainage detail (US wording), see the blue lyme grass soil & potting-mix guide.

Compost for Blue Lyme Grass in the UK — frequently asked questions

What compost should I use for blue lyme grass in the UK?

Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Thrives in lean, sandy, sharply drained soils, including coastal sand and saline ground; tolerates a wide pH. Rich, moist soils encourage even more aggressive spreading. 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 blue lyme grass?

Not on its own — multipurpose compost holds too much water for blue lyme grass and will rot the roots. Cut it roughly 50:50 with horticultural grit, sharp sand or perlite so it drains fast.

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 blue lyme 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 blue lyme grass need grit or perlite added?

Yes — blue lyme grass must have sharp drainage. Add about one part horticultural grit or perlite to one part compost, and always use a pot with drainage holes.

What pot and drainage does blue lyme grass need?

Always a pot with drainage holes. Free-draining sandy or poor soil. 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 blue lyme grass care

See the full blue lyme grass care guide, its UK watering and UK hardiness.