Plant of the Month, May/June

Primula reidii var. williamsii

I am certain that most alpine plant growers will be familiar with this sensational Himalayan primula. This is a beautiful variant of the white-flowering type species, native to the western Himalaya. The species, P. Reidii was first discovered by Duthie in 1883 and later collected the following year in the Garhwal and Kumaon districts of Kashmir growing in wet rocks in glacier moraine. A true alpine plant and it is not surprising that it has only hovered in cultivation.

The variant, P. reidii var. williamsii, however, is to be found in more shaded habitats at a lower altitude in W. Central Nepal. It is easier of culture and maybe this is attributed to its growing on damp, moss-covered rocks. The first discovery was made by Williams on a British Museum led expedition to Nepal in 1952. A collection was made under the number S.S.W 1770 (Stainton, Sykes and Williams). What an important introduction and surely such collections of seed or plant material should be applauded, both then and today, when carried out by responsible parties with the necessary permits. This plant has stood the test of time, while several other species from this notoriously challenging of primula sections, Soldanelloides, have fallen by the wayside.

The outstanding quality of this plant is not only the fact that it CAN be grown, but the fact that it is easily propagated from seed and has the most sumptuous of lavender-blue flowers with the bonus of a very special sweet scent, accentuated as evening approaches, to attract night-flying moths. I say lavender-blue yet this variant also produces pure white flowers, which may have come about soon after its introduction when it will have crossed with the true species (white-flowering). In my experience the white gene is dominant and if the blues are not selected, the white will, over a period of a few years push out the lovely lavender-blue. A simple word of warning! Both coloured flower forms have the same lovely fragrance.

I have been successful growing this plant in a trough or rock pocket in a cool, partly shaded position. An acid mixture, rich in humus, but well-drained will suit this primula, best. During the growing season a lengthy hot spell can kill off plants and care should be taken to water plants, first thing in the morning or late evening and offer plants some extra protection in the form of dead bracken or a similar material.Propagation could not be simpler as an abundance of seed will set on healthy plants. As soon as the seed capsules have ripened, harvest them and place the stems and place in a secure envelope (the seed is very fine!). I would sow it during the winter months and be careful not to sow too thickly. Keep the pricked out seedlings in a cool spot away from the attention of slugs. Grown on in a traditional manner, young plants will flower the following year. What a joy!

Primula reidii var. williamsii received the highest award, an FCC in 1965  from the RHS, as an alpine plant for exhibition.

Availability: Edrom Nurseries: www.edrom-nurseries.co.uk
Kevock Garden Plants: www.kevockgarden.co.uk