Pretty polyanthus

August is the time to sow seeds of polyanthus to give you masses of colourful blooms in 20 months' time, says James Cobbold, as he reveals his top tips

- James Cobbold

THE only way to obtain polyanthus par excellence is to provide them with every possible advantage, and the advantage ranking far above all others is a long period of leisurely growth before their first flowering season, which will be 20 months after an August sowing this year. Long experience has taught me that August is the very best time for sowing with the aim of producing multi-crowned plants of substance and vigour to be planted out in mid-September.

Seed that is freshly harvested and sown now will probably give about 90% germination – the longer polyanthus seed is stored, the less viable it will be. There is nothing as good as freshly harvested seed, no matter how it has been stored. I have twice conducted experiments to confirm this.

Polyanthus parentage 

A little knowledge of polyanthus parentage and antiquity can also be of great help toward an understanding of the plants’ preference for semi-shady situations and a fairly acid soil. What we now call polyanthus is a cross between the common primrose (Primula vulgaris) and Primula variabilis. P. variabilis is a cross between the common wild primrose and cowslip (Primula veris) or possibly the oxlip (Primula elatior). Thus, one parent comes from shady acid woodlands and the other from open meadows and pastures.

Many people believe the real date of origin of polyanthus to be centuries prior to its first recorded mention by Parkinson in 1629. Gerrard, in his Herballe of 1597, does not mention it, but it is well known that the Herballe was far from complete. In any case, this loveliest of all spring-time bedders possesses the attraction of having had many centuries of growth in these islands.