UK compost
What compost for moss rose in the UK?
Portulaca grandiflora
More about moss rose in the UK
Which compost moss rose needs
For moss rose the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Excels in lean, gritty, sandy or even pure sand soil where other annuals struggle. Rich, moisture-retentive soil produces lush foliage but few flowers and encourages root rot. Use a 50:50 mix of potting compost and coarse sand or grit in containers. Good drainage is non-negotiable.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 moss rose 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?
Moss rose 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 moss rose soil & potting-mix guide.
Compost for Moss rose in the UK — frequently asked questions
What compost should I use for moss rose in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Excels in lean, gritty, sandy or even pure sand soil where other annuals struggle. Rich, moisture-retentive soil produces lush foliage but few flowers and encourages root rot. Use a 50:50 mix of potting compost and coarse sand or grit in containers. Good drainage is non-negotiable. 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 moss rose?
Not on its own — multipurpose compost holds too much water for moss rose 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 moss rose perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does moss rose need grit or perlite added?
Yes — moss rose 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 moss rose need?
Always a pot with drainage holes. Poor to moderately fertile, sandy or gritty, sharply drained 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 moss rose care
See the full moss rose care guide, its UK watering and UK hardiness.