UK compost
What compost for thai silk california poppy in the UK?
Eschscholzia californica 'Thai Silk'
More about thai silk california poppy in the UK
Which compost thai silk california poppy needs
For thai silk california poppy the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Eschscholzia californica thrives in the kind of dry, sandy, impoverished soil where most plants struggle. Rich, moist soils produce lush, floppy growth and far fewer flowers. Add grit liberally to heavy clay before sowing. pH 6.0–8.0.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 thai silk california poppy 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?
Thai Silk California poppy 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 thai silk california poppy soil & potting-mix guide.
Compost for Thai Silk California poppy in the UK — frequently asked questions
What compost should I use for thai silk california poppy in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Eschscholzia californica thrives in the kind of dry, sandy, impoverished soil where most plants struggle. Rich, moist soils produce lush, floppy growth and far fewer flowers. Add grit liberally to heavy clay before sowing. pH 6.0–8.0. 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 thai silk california poppy?
Not on its own — multipurpose compost holds too much water for thai silk california poppy 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 thai silk california poppy perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does thai silk california poppy need grit or perlite added?
Yes — thai silk california poppy 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 thai silk california poppy need?
Always a pot with drainage holes. Sandy, gritty, or loamy — dry, low-fertility, well-drained. 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 thai silk california poppy care
See the full thai silk california poppy care guide, its UK watering and UK hardiness.