This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Notwithstanding the reputation this species has of causing eczema, it is still largely grown for market and in private establishments. It is one of the most free-flowering Primulas in cultivation, and flourishes in any good compost of loam, leaf soil, and sand. Of late years great improvements have taken place in it, and the flowers are now quite as big as a half-crown piece, and are produced in fine trusses on stems 6 to 9 in. high, well above the large wrinkled leaves. The colour of the flowers has undergone great change as the result of selection and intercrossing, and there are now pure-white, pink, mauve, heliotrope, purple, rose, and intermediate shades to be met with. To have a crop of plants in bloom during the winter, the seeds should be sown in March, April, and May to secure a good succession.