How to grow lupins

Choosing the right lupins

Lupins come in a wide range of sizes, shapes and flower colours. Their flower spikes are densely packed with small individual pea-like blooms, forming a bold splash of colour. The flowers open from the base of the stem upwards.

There are two types of lupins:

• Border lupins, which come in a range of vibrant flower colours. These are usually perennials, so they die down in winter and re-sprout in spring. A few are annuals, which last just one year

• Tree lupins, which are actually evergreen shrubs with typically yellow lupin-type flowers. They have a year-round presence and can grow up to 2m (6⅔ft) tall and wide

Lupins suit all kinds of garden styles, from traditional cottage gardens to vibrant tropical borders, containers to informal gravel gardens. They also attract pollinating insects.

With so much choice, it helps to narrow down your options by considering the following:

• ​All lupins need a warm spot in full sun for the best results

• They vary in height and size, so consider how much space you have and where in the border you want to grow them. There are small alpine species and dwarf forms such as the Gallery Series, which grow to 38–45cm (15–18in) tall, while others, such as Band of Nobles Series and Russell Hybrids, can be quite imposing, reaching 90–120cm (3–4ft)

• You can use the shorter ones at the front of a border and taller ones towards the back. All sizes can be grown in deep containers (see Planting below)

• Flower colours range from soft pastels to flamboyant pinks, reds, inky blues, sapphires, purples and whites, with some striking colour combinations too. Choose colours that work well with the plants that will be nearby, either complementing or contrasting with them

• It's best to choose cultivars that have an RHS Award of Garden Merit, as this shows they have performed well in RHS trials

How and what to buy

Lupin plants and seeds are widely available during spring and summer in garden centres and online:

• Plug plants are available in spring from some mail-order suppliers. This is a cheaper way to buy, especially in larger quantities, but the choice of cultivars is limited. Additionally, you need to look after these tiny plants carefully for several months before they are large enough to plant into their final position

• You can buy young and more established lupins in containers – 9cm (3½in) or larger – ready for planting out

• Perennial nurseries and specialist lupin growers sell the widest choice, including special mix seeds 

• To track down specific cultivars, you can use RHS Find a Plant. 

Buying: mail order plants

Buying: mail order plants

RHS guide to buying healthy plants

RHS guide to buying healthy plants

All lupins like well-drained soil in full sun. Avoid planting in shade, as flowering will be poor.

In borders

• Plant in spring and early summer, as they become available in garden centres

• Position them in the soil at the same depth they were in the container

• If your soil is prone to waterlogging, or you live in a cold, wet area, grow dwarf or smaller lupins in containers (see below)

Perennials: planting

Perennials: planting

RHS guide to planting shrubs

RHS guide to planting shrubs

In containers 

• For short-term planting, use peat-free multipurpose potting compost

• For permanent planting, use a loam-based compost, such as John Innes No 2 with added perlite to improve drainage

• Apply a potassium-rich feed, such as Vitax Q4 or Phostrogen, weekly throughout the growing season

• Water regularly through the growing season, especially when newly planted and during hot dry spells.

• All container plants (hardy or tender) benefit from winter protection (see Overwintering below)

Growing plants in containers

Growing plants in containers

RHS guide to getting the best from planted containers

RHS guide to getting the best from planted containers

Watering

• Newly planted lupins should be watered regularly during their first summer, especially during hot, dry spells

• Once established, they are reasonably drought tolerant so rarely need watering when grown in the ground, unless there is a severe drought

• Plants in containers need regular watering through the growing season, as the compost dries out quickly. But in winter, protect them from excessive rain by moving them into a cold greenhouse or into the rain shadow at the base of a wall. Keeping them drier will improve their tolerance to cold

• See our video guide to watering efficiently and our guide to recycling and collecting water​

Collect rainwater

Reduce your use of mains water by installing water butts on all your down-pipes – not just on your house but on sheds, garages and greenhouses too

Feeding

Plant nutrition: feeding plants

Plant nutrition: feeding plants

Overwintering

Most lupins are hardy in a British winter if grown in free-draining soil in a sunny spot. However, different types vary in their tolerance to cold, so check plant labels (or cultivar descriptions online) before buying if you want to leave the plant outside over winter. 

Plants in containers are always more susceptible to cold, as their roots are less insulated than in the ground. To help lupins in containers survive winter:

• Move containers to a sheltered spot over winter, where they won't be exposed to really harsh weather

• Protect them from excess winter rain by standing them in the lee of a wall or in a coldframe or greenhouse. Roots that sit in cold, damp compost are more susceptible to rotting

No real pruning is necessary, although deadheading will prolong the display, and you may wish to trim back faded foliage:

• With tree lupins, you can cut off seedheads to stop self-seeding. It will also help to keep these shrubs compact

• With border lupins, cut down the spent flower spikes to the base to encourage more to be produced

• The leaves of border lupins can be trimmed off  when they die down after the first frosts, if you wish to keep the garden very tidy

• All parts of lupins are poisonous, so wear gloves when handling them. See our guide to potentially harmful plants.

It's easy to make new plants by taking cuttings and sowing seeds. But do wear gloves when doing so, as lupins are poisonous.

Tree lupins

• Take softwood or greenwood basal stem cuttings in spring. You can take softwood cuttings before new growth becomes firm and greenwood cuttings when the growth is just beginning to firm. Be aware that too much humidity will rot the cuttings

• You can sow seeds in spring (see border lupins, below)

Border lupins

• Take basal stem cuttings from the base of the plant when the new shoots are 8cm (3in) tall, in mid- to late spring 

• Sow seeds in early to mid-spring. The large seeds have a tough coating, so it is best to nick them with a knife, then soak them in water for 24 hours before sowing. They should germinate in 10–14 days at 10–15°C (50–59°F). However, growing lupins from seed can be tricky, as they are susceptible to rotting if too damp, and they dislike root disturbance, so transplanting may not be successful. On the plus side, many lupins come true from seed, so the offspring should be exactly the same as the parent plant. It is also easy to collect the seeds, as they are large and simple to extract from the seedhead.

• Dividing border lupins is not always successful, as they have a deep tap root. But if a plant develops several crowns, you can divide these in early spring

Propagation techniques

Propagation techniques

Even though lupins are easy to grow, they are occasionally subject to problems:

Poor flowering may be caused by too much shade or by dividing clumps too often. With plants in containers, it may also be caused by overpotting or being excessively pot-bound. Repot every three years or so, into a container that is only slightly larger. To improve flowering, water and feed in spring

Several pests have a taste for lupins, principally slugs and snails, which love the new shoots in spring, but also look out for lupin aphids

​Fungal diseases such as lupin anthracnose and powdery mildew can affect lupins, along with viruses  

​​Lupin seeds may cause severe discomfort if ingested. 

Controlling pests and diseases without chemicals

Controlling pests and diseases without chemicals

Preventing pest and disease problems

Preventing pest and disease problems