UK compost
What compost for dahlia 'bishop of llandaff' in the UK?
Dahlia 'Bishop of Llandaff'
More about dahlia 'bishop of llandaff' in the UK
Which compost dahlia 'bishop of llandaff' needs
For dahlia 'bishop of llandaff' the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Prefers moisture-retentive yet free-draining soil improved with compost or well-rotted manure. Soggy ground rots the tubers. Slightly acidic to neutral pH around 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 dahlia 'bishop of llandaff' 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?
Dahlia 'Bishop of Llandaff' 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 dahlia 'bishop of llandaff' soil & potting-mix guide.
Compost for Dahlia 'Bishop of Llandaff' in the UK — frequently asked questions
What compost should I use for dahlia 'bishop of llandaff' in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Prefers moisture-retentive yet free-draining soil improved with compost or well-rotted manure. Soggy ground rots the tubers. Slightly acidic to neutral pH around 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 dahlia 'bishop of llandaff'?
Not on its own — multipurpose compost holds too much water for dahlia 'bishop of llandaff' 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 dahlia 'bishop of llandaff' perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does dahlia 'bishop of llandaff' need grit or perlite added?
Yes — dahlia 'bishop of llandaff' 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 dahlia 'bishop of llandaff' need?
Always a pot with drainage holes. Rich, fertile, well-drained loam. 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 dahlia 'bishop of llandaff' care
See the full dahlia 'bishop of llandaff' care guide, its UK watering and UK hardiness.