I recently came upon a lovely display of primulas for sale. There were red and orange ones, bright-golden ones, several shades of pink and even one with white blooms. I chose the pot with the dark-purple blooms with the buds just opening, rather than one with mature blooms. When buying any flowering plant, choose one that does not yet have many mature flowers as these will go past rather quickly, reducing the bloom time that you can enjoy.
Primulas are members of the primrose family, a large and varied plant family originating in Europe and Asia. For the most part they are spring-blooming perennials and in milder climates are used extensively in rock gardens or combined with other spring-flowering plants in borders. They are also often planted under deciduous trees where they bloom before the trees leaf out. The word primula means first and these plants are among the first to bloom in the spring, making them prized in outdoor gardens in warmer locations.
The primulas that I came across and that are commonly offered for sale at this time of year are hybrids that are not hardy in our area and so only suited for growing indoors. They are commonly referred to as English primroses or polyanthus primroses, and produce vibrantly coloured blooms — either single ones or there are also double cultivars. The single-bloom types have flowers that measure about three cm across and most have a vivid yellow eye. The yellow ones either lack an eye or sometimes have a reddish colouration resembling veining in the centre of each bloom.
English primulas are not easy-care plants. They tend to be rather temperamental when kept as houseplants, but if given the correct growing conditions, they can be successfully grown indoors, and can be kept after they finish blooming and grown on to produce flowers again. This project will take considerable effort and the results may be disappointing so many gardeners treat these plants as “disposable” and just compost them.
Primulas need rich, well-drained soil which contains lots of organic matter. Commercial growers use a soilless mix that is peat based but home gardeners can improve the composition of the planting medium by adding compost or leaf mould to the mix. Primulas like a nutrient-rich planting medium so if a soilless mix is used a regular fertilizing program will be necessary with a soluble balanced plant food.
These plants also demand good air circulation. If they are kept overly wet and there is not much air movement around them, they can develop rot and both the roots and the leaves can succumb to this. Primroses also prefer cool temperatures. If you purchase a primula, its blooms will last a lot longer if it is located in a cool environment, and it should be placed in a brightly lit location but not in direct sunlight. They like their soil to be kept consistently moist. If some leaves start to yellow then you know that the soil is too wet; if the foliage goes limp then the soil is too dry.
A primula purchased now should bloom until well into April. Removing spent blooms will encourage it to keep producing flowers but eventually the plant will stop blooming. The colour of the blooms darken with age so you will know which blooms are reaching the end of their life by noting their colour. If you want to try keeping the plant alive and getting it to rebloom, after flowering has ceased, keep the plant watered and fed. Remove dead leaves and spent blooms and keep the pot in a well-lit spot. It will keep producing green foliage. During the growing season it could be planted in the ground outside in a shaded location or the pot might simply be placed outside in a sheltered spot. Primulas, however, use lots of water so there is a danger that the soil will dry out if the plant in a pot isn’t watered regularly. The leaves will wilt if the planting medium is too dry. If the plant stays healthy during the summer you might see the development of buds in the fall. At this time the plant can be brought in and treated as you treated it when you first bought it.
Polyanthus primroses are lovely plants and these spring bloomers can brighten our spirits after a long winter. If you simply enjoy the plant while it is in bloom and then discard it, by that time the outdoor garden should be beginning to come alive and our attention will shift in that direction.