Lupins are a cottage-garden favourite, offering height and colour to borders in May and June. Lupin flowers are borne on upright stems with many impressive, pea-like blooms on each stem, and are loved by bumblebees. They make an excellent cut flower.
The majority of lupins are perennial, hardy, and herbaceous, which means their growth dies back in autumn and regrows in spring. Shrubby ‘tree’ lupins are less commonly grown and these form a woody framework of branches. However, lupins won’t last forever – expect to replace plants after about six years.
How to plant lupins
Dig a planting hole in well-drained soil and plant and firm in place, ideally planting in groups of three or five for the best effect. Lupins are best grown in borders due to their fairly short period of flowering and because plants develop long tap roots. To grow lupins in pots, choose containers at least 35cm deep and use a soil based potting compost.
How to care for lupins
Water new plants for the first few months until established and water pot grown plants as needed. Taller lupin varieties may need supporting or staking. Deadhead lupins once flowers have faded, cutting back to ground level, which may encourage a second flush of flowers. In autumn, cut all lupin growth right back to the ground. Lupins are poisonous if ingested so wear gloves when handling.
Watch this video featuring Debbie Copeman, from Glebelands Nursery, as she reveals her three top tips on caring for lupins, including how to keep away slugs and aphids:
View Green Video on the source websiteHow to propagate lupins
Taking cuttings is the easiest method of propagating lupins. Growing from seed or dividing mature clumps are other options.
To collect seed, do not deadhead after flowering, leaving the seed pods to darken and then harvesting the ripe seed to sow the following spring. Before sowing, use a sharp knife to nick the hard seeds, then soak in water overnight or for 24 hours. Sow in pots of moist seed compost mixed with perlite. Lupins do not come true to type from seed, so lupins grown from seed are likely to flower in a mix of colours.
Divide established clumps of lupins in spring, although division can be tricky as lupins develop a strong central tap root. Only divide if the plant has several distinctly different crowns, or growing points. Replant the divisions immediately into soil refreshed with garden compost or soil conditioner.
How to take lupin cuttings
In mid to late spring, select healthy new shoots growing from the base of the clump and take cuttings around 8cm long. Because cuttings are prone to rot, insert in pots of moist perlite mixed with a little seed and cuttings compost. For the best results, put the pots in a heated propagator with the vents of the cover open. Grow on to plant out in autumn or the following spring.
Growing lupins: problem solving
Growing lupins in their preferred conditions of sun, and moist but well-drained soil prevents several potential problems. For example, if lupins go brown and die after flowering, they may have become exhausted by not having had enough water or nutrients during the growing period. Give the soil a good water and mulch, and it may grow back next year.
In dry summers, the lower leaves of lupins may lie flat on the ground. This is nothing to worry about and is usually because of drought, though may also be the result of over-feeding, which causes weak, sappy growth. Give your lupin a good drink and ease up on the plant food, if you have been using any. You may wish to remove the lower leaves that are resting on the ground, as they could be harbouring slugs and snails.
Pests and diseases
Spring shoots of lupins are prone to slug and snail damage, so be vigilant against attack. Protect lupins using a barrier method such as grit, granules, or copper tape, or scatter wildlife-friendly slug pellets.
The lupin aphid (Macrosiphum albifrons) can also be a problem for lupins. These grey aphids can form large colonies and gradually weaken the plant. Birds and other predators should manage aphid infestations naturally but if you don't see signs of the colonies abating, cut off very infested flower spikes and spray with blast of water from your hose. You can use chemical control, but bear in mind that these chemicals also harm, and can kill, bees.
Where to buy lupins online
Great lupins to grow
- Lupinus ‘Cashmere Cream’ – reaches 90cm. Creamy white flowers in June. Buy from Crocus and Gardening Express
- Lupinus ‘Rachel de Thame’ – a stunning white and pink lupin with June blooms. Reaching about 90cm. Buy from Crocus and Gardening Express
- Lupinus arboreus (pictured) - a beautiful evergreen shrub. Height 2m. Buy from Crocus
- Lupinus ‘The Pages’ – dark maroon spires of flowers in May and June reaching an impressive 1.2m. Buy from Crocus and Thompson & Morgan
- Lupinus ‘Russell Hybrids Mixed’ – a real favourite offering a wonderful range of mixed colours. Enjoy yellow, blue, red and pink flowers in May and June. Height 90cm. Buy from J Parker's and Thompson & Morgan
- Lupinus ‘Terracotta’ – warm orange/red flowers in May to July. Reaches a height of 1m. Buy from Crocus and Sarah Raven
Frequently asked questions
Are lupins poisonous?
Yes, lupins are poisonous if ingested by humans or animals. Lupins contain high levels of a toxic alkaloid known as lupanine. Symptoms of lupin poisoning include internal discomfort, dilated pupils, and dizziness. Wearing gloves when handling lupins is a sensible precaution.
Help! My lupins are drooping!
Lupins are prone to drooping if over-watered or under-watered, or after recently having been transplanted. Don't worry – check the soil and if it's dry, give it a good drink. If it's wet, ease off watering for a few days. If you've recently transplanted your lupin, water it every day for a few days until you see signs of new growth. Any drooping parts should perk up but tall flower stems may need to be cut back.
Help! My lupins aren't flowering!
Lupins need full sun to partial shade. If they appear healthy but are not flowering, they may not be getting enough light. If you can give them more sun they should start to bloom. For the best results, try to relocate the plants on a cloudy day and water thoroughly to reduce the shock of transplanting.