The Garden Polyanthus

The Garden Polyanthus
by Angela Bradford

Nobody seems to know the exact origin of the plant we now call the polyanthus. Best guesses seem to be that it was originally a natural hybrid between the common primrose (Primula vulgaris) and the cowslip (Primula veris). The two species hybridise readily where they grow together, and produce a plant - the “false oxlip” -which is showier than either of its parents. Primroses and cowslips are mentioned in the early herbals as they were believed to have many therapeutic qualities and there is no doubt that both primroses and cowslips were grown and appreciated as garden plants from quite early in the middle ages. However, there is no clear indication of when the false oxlip started to be appreciated as a different plant in its own right. By the time Parkinson is writing (1629), we find that that the ordinary wild primrose was not thought worth growing in gardens. Although he does not use the word, there is no doubt that Parkinson is describing garden forms of polyanthus but with nearly all the flowers he describes are yellow, white or green. Yet when we get to the eighteenth century and the beginnings of the polyanthus as we know it today, all the flowers are in various shades of red and remain so until the end of the nineteenth century. Where did the red come from?

In 1640 Parkinson wrote of “Tradescant’s Turkie purple Primrose”, probably a reference to one of the purplish variants of the primrose (now known as subspecies sibthorpii and heterochroma), which are found from Greece eastwards. John Tradescant was England’s first true plant explorer and it is likely that he brought back these purplish primroses. Certainly, a generation after Parkinson, John Rea (1665) is writing about a “red Cowslip or Oxlip”. The word “polyanthus” seems to have been first used for a type of primula in the 1670’s and the earliest known illustration described as a polyanthus is in the 1687 catalogue of the Botanic Gardens at Leyden.

Around the beginning of the1700’s, lacing began to appear in the polyanthus petals. By the 1780’s, the Gold Laced Polyanthus had arrived and was being bred to produce larger, flat flowers with even lacing which reached the centre of the flower. For more than a century, most polyanthus which are described in books or catalogues are dark red or brown with gold lacing. The modern brightly-coloured polyanthus are taken so much for granted now, and are often referred to as “old-fashioned flowers”, that it is difficult to remember that they are, in fact, only about a hundred years old. Gertrude Jekyll, the celebrated English garden designer, had two light-coloured polyanthus, a mottled bronze and a near white. She planted them together, selected out their offspring and by 1880 had produced the first pure yellow polyanthus. After a few years, she was able to market her “Munstead strain” of yellow and white polyanthus. Later, Anthony Waterer added Miss Jekyll’s new colours to his own reds and produced new shades of reds and mauves.

By the 1920s the polyanthus was established as a popular plant for spring bedding, and many of the seed firms were offering their own strains. New colours were being introduced, but the best amongst them was Sutton’s “Brilliance” with “showy orange and red shades”. And by chance, it was Sutton’s catalogue that Florence Bellis saw. Much has been written elsewhere about Florence and the way she overcame poverty and ill health to produce the Barnhaven strain, so I do not propose to tell the story again here. But perhaps this is the place to pay tribute to her. She is very seldom mentioned when the milestones in plant breeding are written about, yet it was she who pioneered the technique of rigorous selection of parent plants and hand pollination which we take so much for granted now and which enabled her to achieve results far more quickly than had been imagined possible before her time. Among her many achievements there are two outstanding. The first was the breeding of the Cowichan strain from the one chance seedling with smouldering red eyeless flowers and bronze foliage, which appeared in a garden in Cowichan Station, British Columbia. The second was to breed the first truly pink strain of primroses and later polyanthus, from the one plant with pink flowers that was found by Linda Eichman. All modern day polyanthus with pink flowers derives from this one plant and it was Florence Bellis who fixed the colour.

Of course, Florence Bellis was not the only one to be working on the polyanthus. For example, Frank Reinelt also started with Sutton’s seeds. During the late 1930s, and inspired by Florence Bellis’s work, he started a program of hand pollination to produce a strain of polyanthus with strong, bright colours that would show up well in the southern sunshine. They were rigorously selected and hand-pollinated under glass. These Pacific Giants came into flower early in the mild Californian climate and were delivered in large quantities to the cold North East where their clear, bright colours and large flowers assured a commercial success. The Pacific’s found their way into many of the modern strains. In most cases, however, in an attempt to produce seed more cheaply, seed was segregated in colour blocks and pollination was left to nature and, inevitably, the strain deteriorated. It also became apparent that years of selection under glass in mild California had bred out much of the polyanthus’s winter-hardiness. A severe winter in the USA in the mid-sixties killed most of the polyanthus that were planted out of doors, and their popularity declined. Sakata of Japan took over Frank Reinelt’s strains, and re-established the colours, but these plants are now specifically intended for pot-culture, so it is important when selecting polyanthus to read the description carefully to be sure you are buying appropriate plants or seeds for either pot or garden culture.

Polyanthus does best in neutral or slightly acid soil. They all appreciate partially shaded positions and large quantities of organic matter. If your soil is sandy, thin or alkaline, your primulas will probably never be happy enough to form established clumps, but you can still grow them as annual bedding plants as long as you grow them in the shade, incorporate as much humus as possible and make special efforts to water in dry weather. Most modern polyanthus are bred to be hardy and are tolerant of a large range of conditions. But the wild plants from which they are descended are woodlanders and the plants are happiest in humus rich, well drained soil, which should not be allowed to dry out. The ideal place would be on a slope under deciduous trees or in a north or east facing bed. Full sun on frozen foliage; freeze/thaw conditions over a long period; waterlogged conditions in winter especially if the ground freezes; or hot, dry conditions in summer are all likely to be fatal. If you expect the first two of these conditions, then the plants should be protected with a loose covering of autumn leaves, wood shavings, bracken, or evergreen branches. All plants benefit from being divided and replanted every two or three years. For best results, feed the plants with a weak solution of high potash or tomato fertilizer every ten days from the time the buds start to form until the first flowers open. A “thank-you” feed when flowering is finished also helps, but don’t feed late in the season and don’t use high nitrogen fertilizers.

Polyanthus can be divided either immediately after flowering, or in the early autumn. I prefer to divide in September and find that the divisions establish quickly to give robust plants full of flowers the following spring. Dividing in May gives your plants a longer growing season, but exposes the young plants to stress from heat and drought when they are at their most vulnerable. However, if you live in an area with severe winters that start early, you should divide in May and pay particular attention to shading and watering.

Lift the plant with a fork, taking enough soil to avoid tearing the roots. Shake off as much soil as possible. If the soil is very heavy or sticky, you may have to wash the soil away from the roots. Leaving the plants standing in a bucket of water for an hour or so will make this easier.

Tease the tangled roots apart with your fingers. If you are lucky, the plant may fall into separate crowns. If not, using a sharp knife, cut down through the fleshy rhizome that binds the crowns together. Try not to be too greedy as larger pieces stand a better chance of establishing, but small pieces that break off can be planted in any case. Discard the old woody centre of the plant. The roots should be pruned back (again using your resharpened knife) to lengths of about four inches (10 centimetres). The pruning has two functions. It encourages the growth of a fibrous root system and the shortened roots are less likely to be damaged when replanted. Cut off the oldest, largest leaves to prevent too much water loss after planting. Throw each prepared division into a bucket of clean water, so that they are full of water when you replant them.

Plant out your divisions either in their new flowering position or in a temporary bed. Primroses don’t seem to resent being moved again as long as you take plenty of the surrounding soil and keep them well watered. Water in your new plantings with a half strength solution of high potash fertiliser. Keep the plants moist and shaded until they are established.

Photo Credit: Debbie Hinchey