How To Grow – Primroses
These traditional fully frost-hardy plants will survive the harshest of British winters and will reward you with a burst of colour in the spring. Primroses are part of the Primula family, named from the Latin primus meaning first, the first flowers to appear in the spring. This is our introductory guide to growing primroses.
Available in a spectrum of colours, primroses will produce flowers at a low level on short stems. They’re ideal for planting in any type of container – or plant them under shrubs with bulbs for a woodland effect. Varieties of primrose range from the coloured display of a traditional choice such as Primrose Rainbow, through to variegated, curly or rose-like blooms. Flowers can densely cluster or be patterned with blotch like centres.
When and Where to Plant
Choose a location with full sun or only partial shade – primroses cope well with being transplanted, so you can move them when conditions change season to season. Dig in plenty of compost and leaf mould. The soil acidity should ideally be 6.5 pH, though this is not vital. For autumn bedding, plant out your plug plants from mid-September to early October, depending on the size of the plants acquired. Grow on plants indoors until they reach 8 to 10 cm in height at which point they’re ready to plant out.
Taller varieties of primrose can be grown as edging plants and as part of a herbaceous border.
How to Plant
To plant in a container, fill the pot or basket up to three-quarters full with multipurpose compost. Carefully remove the plant from the tray or pot and place in position. Fill the container back in with soil and gently firm down. Water in generously. For open planting, dig a hole with a trowel to the same size as the plant’s root ball, and place the plant in position. Fill in the hole and gently firm down the soil. Water immediately; leave a 10 cm gap between plants. Plant your primrose plants so that their crown is at soil level.
Generally, primroses flower in the spring and flowering time can vary depending on weather conditions. After a very harsh winter, the flowering may be slightly delayed, whereas a mild winter encourages earlier flowers.
Primroses are easy to grow and are not prone to attacks from the disease. Keep slugs away with pellets or beer traps if they prove a problem. Remove any leaves which show signs of leaf spot, as these can cause fungal spots. Groups of yellow spots turning darker in colour on the underside of leaves can be identified as Primula Rust – this is not an invasive problem, and the leaves can either be left or removed; grey mould or downy mildew which requires chemical treatment.
Did You Know
Mulch in the autumn and spring to avoid the soil drying out – dry roots should be avoided when growing primroses. A rare pest which is nonetheless worth watching out for is the cucumber mosaic virus which aphids carry from plant to plant. This is manifested on leaves as a mottled ‘mosaic’ pattern in yellow and in a general stunting of growth requiring the lifting of the affected plant.