UK compost
What compost for calibrachoa 'superbells trailing blue' in the UK?
Calibrachoa × hybrida 'Superbells Trailing Blue'
More about calibrachoa 'superbells trailing blue' in the UK
Which compost calibrachoa 'superbells trailing blue' needs
For calibrachoa 'superbells trailing blue' the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. A peat-free multipurpose mix with perlite gives the drainage trailing types need. A slightly acidic pH (around 5.5-6.5) keeps foliage green; alkaline mixes and hard water trigger iron-deficiency yellowing along the trails.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 calibrachoa 'superbells trailing blue' 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?
Calibrachoa 'Superbells Trailing Blue' 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 calibrachoa 'superbells trailing blue' soil & potting-mix guide.
Compost for Calibrachoa 'Superbells Trailing Blue' in the UK — frequently asked questions
What compost should I use for calibrachoa 'superbells trailing blue' in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. A peat-free multipurpose mix with perlite gives the drainage trailing types need. A slightly acidic pH (around 5.5-6.5) keeps foliage green; alkaline mixes and hard water trigger iron-deficiency yellowing along the trails. 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 calibrachoa 'superbells trailing blue'?
Not on its own — multipurpose compost holds too much water for calibrachoa 'superbells trailing blue' 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 calibrachoa 'superbells trailing blue' perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does calibrachoa 'superbells trailing blue' need grit or perlite added?
Yes — calibrachoa 'superbells trailing blue' 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 calibrachoa 'superbells trailing blue' need?
Always a pot with drainage holes. Free-draining, slightly acidic potting compost. 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 calibrachoa 'superbells trailing blue' care
See the full calibrachoa 'superbells trailing blue' care guide, its UK watering and UK hardiness.