Common name: Lupin
The Lupin is a tall perennial that originated from North America, however the strains that are around today are likely to be cultivars of strains developed by George Russell in the 1930’s.
In his day they were treated as an annual but are now considered to be a short lived perennial.
In fact nowadays, if you have the facilities to grow seeds in a heated greenhouse, then seeds sown in January may flower the same year.
In the UK they flower in May and June and will grow on most soils, but prefer lime-free, well-drained soil that is not too rich.
Sow commercial seeds in trays/pots of seed compost and germinate at a temperature of 16°-18°C (60°-65°F).
Soaking the seeds for 24 hours prior to sowing can improve germination, as does nicking the seed at the opposite end to the two eyes.
Alternatively, abrade the seed on a piece of sandpaper.
Germination should take about five to seven days.
Named varieties will not come true from seed.
Prick out once true leaves have been produced into individual pots and grow on till planting out time.
Pricked Out seedlings
Take 75mm (3”) long basal cuttings from the rootstock, preferably with a small piece of rootstock attached.
Insert these into a 50-50 sand and compost mixture and place in a cold frame.
When rooted, pot up into 100mm (4”) pots of potting compost and grow on until planting out time.
Alternatively, divide and transplant mature plants.
Unlike some perennials don’t divide / disturb them in autumn, as they may not recover from this before winter sets in.
Be on guard for Slugs and snails these can damage new shoots.
Look out for Lupin aphid on mature plants, these are specific to lupins, and can spread viruses which may severely debilitate plants.
Plant out January sown seedlings 600mm (24") apart in sun or partial shade in a neutral to acid soil.
Avoid over rich soil as this has a tendency to produce soft growth thus necessitating the need to stake the flowers.
Deadhead flowers regularly to prevent self seeding and to encourage a second flush of flowers later in the year.
Collect ripe seed pods if required.
Sow collected seeds in trays/pots of seed compost and germinate at a temperature of 16°-18°C (60°-65°F).
Plant out seedlings and cuttings 600mm (24") apart in sun or partial shade in a neutral to acid soil.
Avoid overly rich soil as this has a tendency to produce soft growth thus necessitating the need to stake the flowers.
Position away from trees.
Cut down flowering stems to ground level.