Primula japonica 'Postford White' (Japanese Primrose) — Rosette-forming, clump-forming

Overview

Primula japonica 'Postford White' is a rosette-forming, clump-forming perennial in the genus Primula, part of the Primulaceae family, with deciduous, semi-evergreen or evergreen; rosettes of crinkled or mealy leaves foliage. Primula japonica 'Postford White' grows best in partial shade; alpines and auriculas take more sun, and tolerates fertile humus-rich loam; alpine kinds need gritty free-draining soil soils and neutral to slightly acid; asiatic species dislike lime pH. Its UK hardiness is rated H4-H7 depending on group. Suggested uses include bog gardens, streamside planting and woodland gardens. It is native to Japan.

About

Primula japonica 'Postford White' is a rosette-forming, clump-forming perennial in the Primulaceae that flowers from February to June. It produces rosettes of crinkled or mealy leaves and sends up spring flower scapes from the centre of each clump. The cultivar suits reliably damp, shaded spots and favours neutral to slightly acid soil. Position it on a north, east or west-facing, sheltered site close to water or in woodland ground.

Wikipedia contributors, CC BY-SA 4.0 — Primula japonica

About the genus

Primula is a genus of herbaceous flowering plants in the family Primulaceae. They include the primrose, a familiar wildflower of banks and verges. Other common species are P.

Wikipedia contributors, "Primula", CC BY-SA 4.0 — Primula

In the garden

Primula japonica 'Postford White' is a clump-forming perennial native to Japan that offers white spring flowering from February to June. The plant grows from rosettes of crinkled or mealy leaves and belongs to the Primulaceae; different forms within the species range in garden habit, from woodland types to alpines. Locate it in partial shade, on a north, east or west-facing aspect with shelter from strong winds. For the woodland and candelabra-style forms give a fertile, humus-rich loam kept reliably moist; these types tolerate neutral to slightly acid soil and dislike lime. Alpine forms within the broader group need a gritty, free-draining mix and much drier conditions than the moisture-loving types. Hardiness varies across groups (H4–H7), meaning plants range from average hardy through to fully hardy, so choose material suited to your exposure. Use Primula japonica 'Postford White' at pond edges, in bog gardens or beneath a light tree canopy where the soil stays damp. Plant so the crown sits level with the soil and ensure consistent moisture for the woodland/candelabra forms during the growing season. Expect rosettes to produce a sequence of flowering scapes between February and June, providing the main seasonal display.

Growing conditions

Best soil and position for Primula

Sunlight: Partial shade; alpines and auriculas take more sun
Soil type: Fertile humus-rich loam; alpine kinds need gritty free-draining soil
Soil pH: Neutral to slightly acid; Asiatic species dislike lime
Soil moisture: Reliably moist for candelabra and woodland kinds; sharply drained for alpines
Aspect: North, east or west facing
Exposure: Sheltered
UK hardiness: H4-H7 depending on group

Plant details

Primula japonica 'Postford White' size, habit and characteristics

Plant type: Perennial
Habit: Rosette-forming, clump-forming
Foliage: Deciduous, semi-evergreen or evergreen; rosettes of crinkled or mealy leaves
Suggested uses: bog gardens, streamside planting, woodland gardens
Native to: Japan

Care notes

Pruning and caring for Primula japonica 'Postford White'

Cultivation: Match the group to the site and these are easy plants; ignore the distinction and they are short-lived. Candelabra and sikkimensis types want ground that never dries, so a streamside or bog garden suits them perfectly, while auriculas and the alpine species need gritty compost, protection from winter rain, and are traditionally grown in pots in an open frame. Woodland primulas ask for nothing more than leaf mould and dappled shade.
Pruning: No pruning required. Deadhead to prevent self-seeding where it is not wanted, and remove dead outer leaves from the rosettes to reduce rot.
Propagation: Divide after flowering, ideally every second or third year, as congested rosettes decline. Seed germinates best sown fresh and given a cold period, and many species self-sow freely.
Pest resistance: Vine weevil is the principal enemy, especially in pots, along with slugs, aphids and red spider mite under glass.
Disease resistance: Prone to grey mould and crown rot in stagnant damp. Primula brown core, a root rot, causes gradual decline in long-established plantings.

Frequently asked questions

How do I grow Primula japonica 'Postford White'?

Match the group to the site and these are easy plants; ignore the distinction and they are short-lived. Candelabra and sikkimensis types want ground that never dries, so a streamside or bog garden suits them perfectly, while auriculas and the alpine species need gritty compost, protection from winter rain, and are traditionally grown in pots in an open frame. Woodland primulas ask for nothing more than leaf mould and dappled shade.

Where is the best place to plant Primula japonica 'Postford White'?

Primula japonica 'Postford White' prefers partial shade; alpines and auriculas take more sun. It suits sheltered positions.

What soil does Primula japonica 'Postford White' need?

Primula japonica 'Postford White' grows best in fertile humus-rich loam; alpine kinds need gritty free-draining soil soil. It prefers neutral to slightly acid; asiatic species dislike lime soil. Aim for soil that stays reliably moist for candelabra and woodland kinds; sharply drained for alpines.

How do I prune Primula japonica 'Postford White'?

No pruning required. Deadhead to prevent self-seeding where it is not wanted, and remove dead outer leaves from the rosettes to reduce rot.

Is Primula japonica 'Postford White' hardy in the UK?

Primula japonica 'Postford White' has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.

How do I propagate Primula japonica 'Postford White'?

Divide after flowering, ideally every second or third year, as congested rosettes decline. Seed germinates best sown fresh and given a cold period, and many species self-sow freely.

More in the Primula genus

Browse all Primula →