UK compost
What compost for streptocarpus 'purple haze' in the UK?
Streptocarpus 'Purple Haze'
More about streptocarpus 'purple haze' in the UK
Which compost streptocarpus 'purple haze' needs
For streptocarpus 'purple haze' the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. An open mix with perlite keeps the fine roots aerated. The plant flowers best slightly pot-bound, so choose a shallow, snug container with good drainage.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 streptocarpus 'purple haze' 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?
Streptocarpus 'Purple Haze' 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 streptocarpus 'purple haze' soil & potting-mix guide.
Compost for Streptocarpus 'Purple Haze' in the UK — frequently asked questions
What compost should I use for streptocarpus 'purple haze' in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. An open mix with perlite keeps the fine roots aerated. The plant flowers best slightly pot-bound, so choose a shallow, snug container with good drainage. 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 streptocarpus 'purple haze'?
Not on its own — multipurpose compost holds too much water for streptocarpus 'purple haze' 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 streptocarpus 'purple haze' perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does streptocarpus 'purple haze' need grit or perlite added?
Yes — streptocarpus 'purple haze' 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 streptocarpus 'purple haze' need?
Always a pot with drainage holes. Light, free-draining African-violet or peat-free houseplant mix. 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 streptocarpus 'purple haze' care
See the full streptocarpus 'purple haze' care guide, its UK watering and UK hardiness.