Tree Lupin or Lupinus arboreus
The Tree Lupin or Lupinus arboreus is not exactly a tree, more of a shrub that reaches around 1m – 1.5. Long flowering from spring through summer with attractive fragrant creamy yellow flowers, this is a tough plant that seems to thrive on dry conditions. Originally from the SanFancisco Bay area, it grows well in full sun to part shade and is not fussy about soil type.
Lupinus arboreus ‘Alba’ is a wonderful white flowering plant, nice olive green foliage with white flower spikes rising above in spring. Will reach around 1.5m in height
Plant in a sunny position in a well drained soil, water in well and then leave this plant to its own devices.
Problems
Although the flowers are attractive the plant can become an environmental weed especially in coastal areas. The plant itself can be easily removed, it is the seeds that are the problem. If you are growing it you will probably need to deadhead after to flowering to keep it and prevent self seeding. It is a little disappointing that some nurseries still list this plant without warning of the weed potential.
What to plant instead
Look for the readily available Russell Lupins, or perhaps the hybrid L.arboreus x polyphyllus.