My infatuation with primroses began many years ago while as a youth working among woodlands, water meadows and cottage gardens in the British countryside, where the cool, moist climate is ideal for their culture. Prized for their outstanding beauty and wide range of heights, colours and types, primroses (Primula spp.) are one of the most versatile groups of plants. And for some of us, they are an emotional link to our British heritage.
In my opinion, Primula is one of three great plant genera, the other two being Rhododendron and Rosa. There are primroses suitable for growing in many situations, such as shade and rock gardens, alongside bogs and ponds, in containers and window boxes, and even indoors, where less hardy types add colour to cool windowsills. Some 430 species of primroses and countless cultivars are distributed throughout the moister, cooler regions of the northern hemisphere. Nearly 335 species can be found in the great mountain range of the Himalayas and western China alone, with more than 50 of them growing on a single mountain. By contrast, Europe has just 34 species and North America, 20.
Although healthy, well-grown plants can withstand tough conditions, watch out for frost heave caused by winter freezing and thawing, and heavy rains, which can expose their shallow roots. If either occurs, gently press the plant down into the soil and cover exposed roots with leaf mould, peat or compost, mixed in with a bit of composted cow or sheep manure and bone meal (one cubic metre of manure to 50 grams of bone meal). Applied yearly in spring, this mixture also makes a good top dressing.
Primroses do have a few pests, so keep a sharp eye out for slug and black vine weevil damage. The former needs no introduction. Vine weevils are small dark beetles with a long mouthpart, and are most active at night. The adults chew pieces out of the leaves, spoiling their overall beauty. After feeding for three weeks, adults lay eggs, and weevil grubs develop underground; they may devour the roots, causing the plant to collapse. If this happens, the plant is unsalvageable and must be destroyed—also remove the soil around the roots to reduce the larvae population. After 13 years, I have yet to lose a primrose to weevils, though I must admit by late summer many of their leaves look ratty. But I can live with this.
Commonly used terms to describe primroses
- Drumstick Group: denticulata types with round clusters of blooms on long, upright stems
- Farina: a white or yellow waxy meal sometimes found on primrose stems, calyx or leaves
- Hose-in-hose: flower calyx is transformed into a second petaloid structure, giving the impression of one identical flower within another
- Jackanapes: floral and leafy tissues combined in the calyx
- Jack-in-green: leafy, enlarged sepals that form a green collar or ruff around the flower
- Paste: the eye of show (exhibition) auriculas, which must be pure white and unblemished
- Salverform: a flower shape with a long, slim tube that flares out into flat lobes
Image: Unidentified Primula species