Primroses are meant for the gardener who is impatient to put on an early-spring display of vibrant colors. Some of the blooms - for instance, the bicolors combining a chrome-yellow core, or “eye,” with a deep-purple or dark-ruby margin all around it - are downright gaudy. But for those who go for dainty colors, there also are subtle lavenders and elegant maroons, immaculate whites and several shades of pink.
Primrose seedlings - sold in plastic pots two to four inches square by garden centers and farmers’ markets, by most nurseries and a good number of roadside stands - offer an instant garden in nearly every color of the rainbow. If they are not yet in bloom when put on sale, they soon will be, and the blooms may last several weeks, unless they are wilted by hot weather.
Though there are hundreds of species growing across the globe, the primroses have been frequently and enthusiastically hybridized in the British Isles since the 17th century, and the hybrids’ advantages include a profusion of blooms and a palette of colors that go beyond what the parents have to offer. The hybrids are thought to stem from several species.
One of the venerable ancestors is undoubtedly Primula vulgaria, known as common primrose and, confusingly enough, also as English primrose. It has a pale-yellow bloom with a somewhat-darker eye about an inch in diameter, and the bloom is borne singly on top of slender, fuzzy stalks. The petals are slightly scented, as are some of the polyanthus hybrids. The leaves rising from the center are crinkled and scalloped and form a handsome rosette. Neither the height nor width of the plant exceeds 10 inches.
The common primrose is a beloved wildflower that stands for innocence and cheerfulness among its many aficionados. It brightens the English countryside. In the western and southern parts of the European continent, its presence is noteworthy in hedgerows that once served as property markers and are nowadays particularly useful as wildlife habitats. It accepts this area’s heavy, clay-dominated soil and will increase and multiply, particularly when planted near streams or in some other damp spot shaded in the summer.
Both common primroses and polyanthus are considered sturdy perennials, with a tendency to develop hefty clumps. Easy to raise from seed, they also may spread freely from seeds scattered about.
Gardeners who have had problems with polyanthus disappearing after a year or two, often with cultivars from the series called Pacific Giants, may have forgotten that their soil must be rich in organic content and kept moist, or at the very least not allowed to dry out.
Another key requirement is lots of sun in the spring, particularly in early spring, and mostly shade in the heat of summer.
One possible reason some of the more-sophisticated primroses - such as the Japanese primroses - do not come back in the spring is that they got waterlogged in the winter. Heaving also may occur, exposing the roots to chilly air. Mulching is recommended, both for the summer and the winter.
If properly cared for, Japanese primroses, also known as candelabra primroses, do well in our area. Blooming in May or June, they may reach a height of two feet, with the same spread. Drumstick primroses (primula denticulata) are shorter - about a foot tall - and among the earliest perennials to come up in the spring. The buds form a dome centered in a leaf rosette. After the buds open, they turn into fluffy spheres about two inches across.
If a clump of primrose looks too crowded, division is called for. Veteran gardeners dunk the clump into a bucket of water and use the gentle flow from a hose in washing the soil away from the roots. A gentle tug will then separate the individual crowns.
Early spring is a good time for breaking up overcrowded specimens. Two caveats are in order: One,
some people develop a rash after they touch primrose leaves. The rash usually does not last very long, but it itches; thus, wearing gloves while handling primroses is a smart idea. Two, the fleshy leaves of primroses often attract a host of pests such as flea beetles, aphids and red spider mites. Slugs and snails also feed on the leaves.
Nevertheless, it is a plant worth cultivating, particularly in a rock garden where its neat, low rosettes of dark-green foliage and its brilliantly colored, compact petals look dramatic when nestled among craggy boulders. But above all, primroses call off winter.