Multi-coloured marvels

One group of plants that encapsulates the very spirit of RHS Garden Harlow Carr, is the ‘Harlow Car’ hybrid primulas

Primua 'Harlow Carr' hybridsWhen garden visitors enter the gardens, wander down past the heather beds, and the tarn lawns towards the Streamside, they will be immediately faced by mixed blocks of intense colour – Primula japonica ‘Harlow Car’ Hybrids. This not-so-subtle group of plants comes in a range of colours from pink, peach and orange to yellow, purple and – if you’re lucky – white. Flower stems reach an impressive 60cm (24in), with whorls of flowers creating a candelabra effect.

These plants are semi-evergreen, producing rosettes of pale green leaves from which the tall flower stems erupt. They originate from China and the Himalayas, and thus are ideal for woodland, damp or even extremely wet places, thriving along streamside and boggy areas alike.

Cross breeding

Primula japonica ‘Harlow Car’ hybrids are heavily hybridised. They originate from the Northern Horticultural Society days before Harlow Carr merged with the RHS. Then, primulas were grown along the streamside in distinct species groups. Blocks of orange P. bulleyana growing in close proximity to blocks of mauve P. beesianum, red P. japonica and purple P. pulverulenta. Over time, these closely related plants cross bred and intermixed, forming the much-loved Harlow Car hybrid primulas we know today.

Seed of this newly recognised Primula japonica ‘Harlow Car’ hybrid was first made available in the early 1960s. Eagle-eyed readers may notice that the spelling of Harlow Car hybrids has only a single ‘r’ – this was a mistake when it was first named that has stuck ever since. Plants are available in the Harlow Carr shop and online plant nurseries.

Streamside primulasToday, the Garden propagates 500 seedling ‘Harlow Car’ primulas every year. Each batch of hybrids differs in colour composition, some predominantly pink, some more yellow or orange. Rarer colours such as white and purple are favoured, and seeds of these more unusual-coloured plants are painstakingly selected and grown on. The ideal is to have an equal number of all colours in a Harlow Car hybrid primula mix.

The Primula japonica ‘Harlow Car’ hybrids can be found planted in large groups along the iconic streamside planted alongside blue poppies, ferns and other bog-loving plants. With the redevelopment of Harlow Carr woodlands, large groups of these plants can also be seen in the woodland near the Bettys shelter.

Growing conditions

When growing these plants at home, remember they prefer partial shade and can only be grown in a sunny position if the soil is always moist, but not waterlogged. Plants grow best in deep soil that is rich in well-rotted organic matter. These plants are semi-evergreen, so do not panic if leaves die back over the winter period – they will re-leaf in spring. They are a low-maintenance plant and easy to grow, providing they are placed in the correct position.

Read more

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RHS Garden Harlow Carr
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