UK compost
What compost for lobelia erinus 'techno heat blue' in the UK?
Lobelia erinus 'Techno Heat Blue'
More about lobelia erinus 'techno heat blue' in the UK
Which compost lobelia erinus 'techno heat blue' needs
For lobelia erinus 'techno heat blue' the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Rich, moisture-holding soil suits it. In baskets and containers use a quality peat-free multipurpose compost, ideally with water-retaining organic matter for the long flowering season.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 lobelia erinus 'techno heat 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?
Lobelia erinus 'Techno Heat 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 lobelia erinus 'techno heat blue' soil & potting-mix guide.
Compost for Lobelia erinus 'Techno Heat Blue' in the UK — frequently asked questions
What compost should I use for lobelia erinus 'techno heat blue' in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Rich, moisture-holding soil suits it. In baskets and containers use a quality peat-free multipurpose compost, ideally with water-retaining organic matter for the long flowering season. 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 lobelia erinus 'techno heat blue'?
Not on its own — multipurpose compost holds too much water for lobelia erinus 'techno heat 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 lobelia erinus 'techno heat 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 lobelia erinus 'techno heat blue' need grit or perlite added?
Yes — lobelia erinus 'techno heat 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 lobelia erinus 'techno heat blue' need?
Always a pot with drainage holes. Fertile, moisture-retentive, free-draining loam or 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 lobelia erinus 'techno heat blue' care
See the full lobelia erinus 'techno heat blue' care guide, its UK watering and UK hardiness.