Primula marginata ‘Casterino’

Photo: Jim Almond

An alpine garden without any forms of Primula marginata adorning it, is missing out on one of the finest and easiest of all the European primulas. The species belongs to the Maritime and Cottian Alps of Italy and France occupying  precipitous limestone (yet not exclusively) rock fissures and steep humus slopes sometimes preferring the dappled shade of trees and shrubs. It flowers in late spring ( May and early June) in nature, while its peak of flowering is usually April in cultivation. The flowers are held in an umbel of up to 10 or more and are generally lavender-blue to violet and in its best forms, as in P. marginata ‘Caerulea’ a fine clear blue or pure white with the recommended P. marginata ‘Casterino’. The flowers have a faint scent, but it is the heavily-farinose, leathery foliage that also emits a fine pungent scent and can be quite spectacular with its deeply serrated margins.

I have found that when growing the species and its many cultivars in the garden it is not fussy about the soil pH but rather, is concerned with fine drainage and loves to be wedged in between large rocks where its woody, truncated stems can delve deeply into the cooler depths of a crevice and allow the heavy umbels of flowers to shower down in all their beauty. I like to afford the plants a little shade if at all possible. To offer a calcareous substrate offers an advantage when it comes to accentuating the lovely, silver-farinose foliage which is markedly showier with a higher ph.

As well as the recommended cultivar, there are many other forms and excellent hybrids available and they are often best selected when flowering from a nursery exhibiting at one of the Spring Shows.

If readers would like to raise their own plants, this can be achieved by saving the seed and then selecting from the 2 yr old seedlings or by raising clonal material from stem cuttings taken from non-flowering shoots in early June and rooted in a sand/perlite mixture.

My recommended cultivar was a selection made by a good friend of mine, the late Bernd Wetzel, who operated a marvellous nursery in Wuppertal, Germany with his wife and family and commemorates a rich valley by the same name in Italy.

Availability: Aberconwy Nursery – tel, 01492 580875