A noxious weed in one country is often a treasured garden gem in another, and believe it or not, lupins fall into this category.
In parts of New Zealand and Northern Europe, Lupinus polyphyllus, the species behind many of our cultivated garden hybrids, is an invasive. In New Zealand’s South Island and in countries like Finland and Sweden, it spreads rapidly, covering entire riverbanks and roadsides with spectacular, towering spires in blues and purples.
Whilst the displays may be breathtaking and draw tourists in their droves, in these fragile habitats, the plant crowds out native species and alters the natural balance by enriching the soil with nitrogen, favouring invasive growth over indigenous flora. Its spread also disrupts river systems, threatening the survival of rare birds and native wildlife.
In our gardens, the lupins we grow, mainly derived from Lupinus polyphyllus but bred into stable hybrids like the famous Russell strains, are generally well-behaved.
They are short-lived perennials that often need a bit of mollycoddling to encourage them to thrive. Far from being invasive, they usually vanish within a season or two.
They were once the stars of early summer, loved for their upright form and bold colours. Their rise to fame came largely thanks to George Russell, a railway worker from York with a passion for plant breeding.
Over decades, he selected and stabilised hybrid lupins for rich colour, tighter flower spikes, and stronger garden performance. His Russell hybrids exploded onto the horticultural scene in the 1930s and quickly became a fixture of the cottage-style border.
They can be tricky, and I have often found them to be short-lived, fussy about conditions, and prone to attack from both pests and disease. In spring, the newly emerging lupin shoots emerge like a gourmet feast for slugs and snails. Control them at this stage to allow the plant to establish, use barriers of sheep’s wool pellets, slate mulch, crushed eggshells or sharp horticultural grit around the base of plants.
Then there are the aphids; lupins are loved by greenfly and blackfly, and more recently, the lupin aphid, which is a large, pale grey/green aphid that has become a serious pest of garden lupins in recent years.
Unlike smaller aphid species, the lupin aphid tends to appear in dense, dramatic infestations, often on the undersides of leaves and along the flowering stems.
Entire plants can be overwhelmed within a day or two, with distorted growth and wilting, or stunted flowers. The sheer volume of aphids can physically weigh down stems and produce large quantities of sticky honeydew.
What makes them particularly challenging is that natural predators like ladybirds and hoverflies often arrive too late or in insufficient numbers to provide effective control. Because of this, early intervention is key.
Avoid using chemical sprays, which will do far more harm than good. If infestations are caught early, a sharp jet of water or pruning off the worst-affected shoots will keep them in check. A homemade garlic spray will make the plants unpalatable to aphids without upsetting the wider ecosystem.
Our warm and damp climate creates the ideal conditions for the development of many fungal infections, such as powdery mildew and grey mould. Good air circulation is crucial.
Don’t cram plants too closely together, and water early in the day so foliage dries quickly. If mildew does appear, remove the affected leaves and dispose of them; don’t compost them, as they can end up spreading the spores. Once attacked by aphids, the lupins’ resistance to infections is lowered, so controlling the insects is vital.
Lupins growing at Lake Tekapo, South Island, New Zealand. File picture
Despite all these challenges, lupins are worth the effort when they succeed. The key is giving them what they need. They like full sun and free-draining, slightly poor soil, not the rich, moist compost we tend to offer everything else. Avoid waterlogged ground, particularly over winter, or the roots will rot.
Shelter them from strong winds, as the flower spikes are prone to snapping. If your garden is exposed, stake them early or grow them through low supports.
To give yourself every chance of success, choose your variety wisely; the Russell Hybrids remain some of the best to grow. Look out for cultivars like The Governor, My Castle or The Chatelaine. For smaller spaces or containers, the Gallery series offers a compact alternative with all the flair of their taller cousins.
Definitely worth seeking out are the West Country lupins, a newer range bred in Devon for better vigour, richer colours, and improved weather resistance. These plants tend to produce dense, uniform flower spikes and come in some truly spectacular shades.
Cultivars like Persian Slipper, in a rich blue and cream, or Masterpiece, with its deep purple and orange tones, are particularly eye-catching, whilst L. Blossom is the most beautiful and delicate, pale pink.
To prolong flowering, cut back the main flower spike just as it starts to fade. This often encourages a second flush from side shoots.
Lupins are worth the effort. There is something joyful about them, a reminder of the glory days of gardening when every border had its spires and every June came with a riot of colour.
They might not last forever, and they might ask a bit more than many more modern plants, but perhaps, that’s part of the charm.
