UK compost
What compost for rough columnea in the UK?
Columnea strigosa
More about rough columnea in the UK
Which compost rough columnea needs
For rough columnea the mix to buy is peat-free ericaceous (lime-free) compost. A blend of fine orchid bark, coir, and perlite with a higher proportion of coir than typical columnea mixes suits this species, as its montane habitat has cooler, more moisture-laden air. Target pH 5.5–6.5.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 rough columnea 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?
Rough Columnea is a lime-hater: it needs an acidic, lime-free ericaceous compost. In ordinary (limey) multipurpose it slowly yellows between the leaf veins as it locks out iron. Buy a bag labelled "ericaceous", and in a hard-water area water with rainwater where you can, since tap water is slightly alkaline.
For the full recipe, pH and drainage detail (US wording), see the rough columnea soil & potting-mix guide.
Compost for Rough Columnea in the UK — frequently asked questions
What compost should I use for rough columnea in the UK?
Use peat-free ericaceous (lime-free) compost. A blend of fine orchid bark, coir, and perlite with a higher proportion of coir than typical columnea mixes suits this species, as its montane habitat has cooler, more moisture-laden air. Target pH 5.5–6.5. 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 rough columnea?
No — rough columnea needs an acidic, lime-free (ericaceous) compost. Standard multipurpose is too limey and will slowly cause yellowing between the leaf veins (lime-induced chlorosis). Buy a bag labelled "ericaceous".
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 rough columnea perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does rough columnea need grit or perlite added?
Not essential, but a couple of handfuls of perlite in the mix improves aeration and guards against overwatering — useful on a cool, damp British windowsill where compost stays wet longer.
What pot and drainage does rough columnea need?
Always a pot with drainage holes. Humus-rich, moisture-retentive epiphyte 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 rough columnea care
See the full rough columnea care guide, its UK watering and UK hardiness.