Guide to growing Lupin - Lupinus
Lupinus can be hardy annuals, half hardy annuals or hardy perennials.
They reach from 30cm to 1.5 m in height depending upon species and variety.
They have stiff erect spikes that carry pea like flowers that grow in racemes.
Lupinus flowers are a variety of colours including purple, blue, pink, white and yellow.
The perennial varieties of lupinus come into bloom in the summer, whilst annual varieties will flower about two months after being sown.
Some common names for Lupinus include Lupin, Lupine, Bluebonnet and Texas Bluebonnet.
How to grow Lupin
Annual varieties of Lupinus should be sown following the last frost; the perennial varieties can be sown in either autumn or just before the last frost of spring. The Lupin seeds should be planted at a depth of about 3mm, and can grow in either a sunny or partially shaded part of the garden that has good drainage. Lupins prefer to grow in a moist soil that is slightly acidic to neutral (pH 5.5 to 7).
When starting to grow Lupins indoors for later transplanting then this should be initiated about 8 weeks in advance. The germination of lupin seeds can take from two to 8 weeks. First the lupin seeds should be chipped and soaked for a day in warm water. They should then be incubated at about 12 to 18 degrees centigrade. Once ready, Lupinus should be transplanted in the garden with a spacing of 30cm (annuals) or from 30 to 90cm (small to large perennial Lupinus).
Caring for Lupins - Lupinus
Once established Lupinus members are fairly easy to look after. They require a regular watering and the Lupin flowers should be dead headed regularly. It is best to feed them with a fertilizer rich in phosphorous and low in nitrogen. When growing perennials cut the flower stalks down to the base once the flowering season is over. If you require more perennial Lupinus plants then they can be propagated by division or from cuttings in the spring.