Spring is a time when there are so many plants bursting into growth and flower that sometimes it’s hard to see the wood for the trees, or in our case the plants for the flowers. So this month I thought it might be appropriate to consider some of the smaller and less obtrusive spring plants that are often overlooked.
The primula family is one of the stars of late winter and early spring and every year thousands of fancy primroses and polyanthus are sold and planted as means of providing quick colour. However, the plants that we see most often are simply the most flamboyant and highly hybridised members of a far wider family that includes many small treasures that are hardly known or that pass unnoticed.
My favourite is a species that is said to be the smallest of all the primroses: Primula warshnewskyana. Although it eventually develops into a decent sized clump, when it first comes into flower it is a genuine example of the name being bigger than the plant. One or two flowering rosettes could be planted in a thimble. Yet it is such a tough and undemanding little plant, asking only to be protected from being overgrown by more rampant greenery. Primula pubescens, particularly the pale yellow ‘Harlow Carr’ is another charmer. Rather like an auricula in foliage and flower, but more delicate and graceful than its large cousin. For something a little more showy and unusual tryPrimula vialii. Although this species is somewhat frost tender and inclined to be short-lived, it is worth growing and persevering with for its very striking flowers. These are clustered on spikes that are held well above the foliage. They are red in bud and open to pinkish lavender. The red buds overlap like tiles on a roof so that in the early stage of development the flower stems resembles the top of a miniature steeple.
The Epimedium species seldom receive any great attention but they are among the most adaptable small perennials. They develop into spreading clumps that are ideal for carpeting small areas in a woodland. Totally dormant in winter, they come into growth in earliest spring, often flowering before the foliage is fully developed. The most common epimedium is the pale yellow-flowered E × sulphureum, which is usually the first to bloom along with the closely related, white-flowered Coptis quinquefolia. The white E. × youngianum follows in mid spring while the fanciest of them, E. grandiflorum, flowers on and off from spring to autumn. Epimediums offer the bonus of rich autumn foliage colour which can be just as much of an attraction as the delicate little flowers. As is the case with many plants, those with the simplest flowers tend to produce the best foliage colour.
The wood anemones, too, have their share of lesser-known beauties. Anemone nemorosa and A. blanda are widely grown, but how often do we see good clumps of the pale yellow A. sieberii or its brighter relative A. ranunculoides. Although these plants are a little more difficult to cultivate than the common species, they are by no means impossible provided the soil has ample humus and the winter and early spring climate is not too warm — anywhere in the South Island and the lower North Island will do. Light filtered shade suits them best. Along with these and many other uncommon species there are also the more delicate forms of the common A. nemorosa. Particularly attractive is the pale pink-flowered ‘Allenii’ with its nodding blooms. The white double, ‘Bracteata’, is very useful for naturalising in woodland and can lighten up a dark corner.
Hacquetia epipactus is a very unusual little perennial that looks like it is closely related to the wood anemones but which actually belongs in the Umbelliferae along with dill and fennel. This hardy woodlander begins to flower in very early spring before developing any foliage. Indeed the first sign of life is the emergence from the earth of tiny green-bracted yellow flowers. These initial, usually rather tatty, flowers are soon followed by foliage and slightly larger blooms. Hacquetia is not the most beautiful plant but it certainly has its charms. It is also extremely hardy, it comes into bloom from early August and is unfazed by frost. In the heavy Christchurch snow of 1992 it carried on unchecked despite being buried under snow for several days while in flower.
Asperula gussonii is a small, wiry-stemmed perennial cushion plant that is almost a sub-shrub. It has tiny, bright green leaves with silvery undersides and is more or less evergreen though it can be rather untidy in winter. It demands perfect drainage and is really at its best in a rockery or alpine pan. In spring it produces heads of minute pale pink flowers that develop from deeper coloured buds. The effect is rather like a very small-flowered daphne or erica.
The erica family itself includes many hard-to-get but very choice small shrubs. Rather than tempt you with the real rarities I’ll mention a couple that are somewhat easier to obtain if you are prepared to search for them. The mountain laurel (Kalmia latifolia) is a much loved and widely grown shrub but the closely related sheep laurel (Kalmia angustifolia), which occurs naturally in much the same parts of eastern North America is far less common though easier to grow. Its foliage is mid green and rather narrow, quite unlike the leaves of K. latifolia. Its flowers are deep pink and closely resemble those of K. latifolia in form while being about half the size. Although it has been overshadowed by the more flamboyant mountain laurel, K. angustifolia is a colourful, extremely hardy evergreen shrub that is well worth growing. It can grow to 1 m high and wide in the wild but is seldom more than two-thirds that size in cultivation. It is easily grown and seems more adaptable than K. latifolia, which has a reputation for being temperamental.
The bog rosemary (Andromeda polifolia) is a near relative of the kalmias and superficially resembles K. angustifoliabut is smaller still. This species, the only one remaining in a once large genus, forms a small mound that becomes covered with tiny, pink, bell-shaped flowers in spring. Cultivars with deeper pink or white flowers are available. This plant has a large range in the wild that extends into the Arctic Circle. It is essentially a cold climate plant that does not do well where the winters are mild. Choose a position that only receives only morning sun and make sure the soil is humus-rich yet well drained. It grows well in pure peat but any leaf-based compost will do.
Finally, one of my all-time favourites: Salix anoda. For most of the year this miniature willow is nondescript 60 cm–1 m high deciduous shrub that doesn’t merit a second glance, but in September and October it produces the most striking pussy willow catkins. The beauty of this plant is that something so ordinary can suddenly spring such a surprise. Like most willows, S. anoda has somewhat aggressive roots. It’s nothing like as strong-growing or ground-robbing as a weeping willow or a genuine pussy willow but it still needs room to spread.
There are so many plants that tend to be ignored while the cherries, daffodils, rhodos, camellias and the like hog the limelight that an article like this could go on forever. However, I think I’ll stop it here. The important thing is not to downgrade the common spring flowers but to remember to look for some of the real novelties that don’t rely on sheer flamboyance for their charm and that can really help to personalise your garden.