Tree lupins growing tips
Lupinus arboreus, commonly named tree lupin or yellow bush lupin, is an evergreen shrub of medium dimension characterized by small, fragrant yellow flowers, densely grouped in racemes. Its foliage is also beautifully elegant, composed of palmate leaves, green and grey with a silvery sheen. Unlike many other lupins tipical of Great Britain, this is a variety originally from the Californian coast.
How to grow tree lupin
Lupinus arboreus belongs to a type of plants very common and always well loved in Great Britain, as recorded as far back as the 15thcentury. This particular variety, though, originally comes from the American continent, and is a very strong and resilient plant. It propagates by seeds as well as basal cutting, and is a fast grower- it can reach upto 6ft in its first year if the conditions are right! The ideal conditions for these lupins is a sunny and open spot in well drained, sandy soil. Planted in spring, it flowers in Spring and Summer, and generally doesn't need any pruning. However, if overgrown, it can be cut back quite hardly without causing it any distress. Generally, for a late September flowering, it is advisable to keep cutting back any spent flowers, to let the new shoots grow.The tree lupin grows in well drain, sandy soils and direct sunlight, so choose a sunny spot for it, with at least 4 hours direct sunlight available. Seeds are widely available and can be planted singly in small pots with a base of seed-compost. The young plants will need to be moved in larger pots at least twice. They will be ready to ne put out when they are about a foot tall and wide..After choosing a nice spot with direct sunlight, prepare the ground by working it thoroughly. There is no need to add compost at this stage, but in case of heavy soils, some gravel may be mixed in.
Apart from its decorative value, this kind of lupins is also a great companion to all garden life. Because it fixes nitrogen in the soil, it makes it more fertile. So the bigger your tree lupin grow, the richer the soil will be for all the other plants. The ones that best fit with its beautiful yellow flowers would be Eryngiums, with large blue bracts, and Brookside Gerainium with blue, rounded flowers. Also, tree lupin can be amazingly combined with yellow day lilies.
Seeds are available online: