This weeks plant of the week is one that just seems to flower for months and months although I feel it’s March and into April when they really are their best. It is certainly one of my favourite plants since i moment I saw it growing in Sir Harold Hillier Gardens, down near the pond, indeed it was the original plant that was introduced by Hillier Nurseries.
This original plant of Sophora ‘Sun King’ came from some seed Nothofagus seed sent to Sir Harold Hillier Gardens from Chile. When the Nothofagus germinated it was found to have an interloper amongst them, this grew into a very beautiful shrub indeed, flowering some years later. It was thought to be a form of S.microphylla although it is now thought to of been a hybrid. It was introduced by Hilliers in the late 1990’s after it had done so well at the gardens surviving many cold winters and it is indeed still growing away strong to this day, my photos are of that particular plant!
There is a lot of rubbish spoken about Sophora ‘Sun King’ about its height and soil dislikes. It does only get to a maximum size of about 3m in height and width as a few standing shrub, trained as a wall shrub it is able to get a little taller, up to 4m in height but no where near the 8m I have seen written down. Soil wise, Sophora ‘Sun King’ will take most soils from shallow chalk to clay, (yes even read it dislikes clay, the original plant is on solid london clay!) as long as it isn’t waterlogged. Again it will take most aspects although if the garden is particularly cold, a slightly more sheltered spot is better. It flowers much better if it is in a sheltered spot. Sophora ‘Sun King’ starts producing its yellow pea like flowers after its around 8yrs old and these start appearing in January and will continue flowering well into May some years. In Chile, the flowers of Sophora sp are mainly propagated by hummingbirds but here in the uk, it’s the bees that help the process. These flowers are offset by the stunning dark green foliage with up to 40 leaflets are used to form each leaf. It is evergreen but in a very hard winter, it will drop its leaves. The Name Sophora comes from Arabic meaning a small tree with pea like flowers. Sun King is partly in homage to its Chilean roots as well as the colour of the flowers.
Sophora ‘Sun King’ has very few pests and diseases that attack it apart from the usual slugs and snails when young. Like all plants, it would benefit from a feed of Vitax Q4 in the spring as well as a compost mulch to help increase the health of the surrounding soil. Sophora ‘Sun King’ is propagated by grafting on to a rootstock of Sophora microphylla in the late winter early spring. It is very difficult to propagate from cuttings although I have heard of people succeeding using Air layering methods.
Sophora ‘Sun King’ is now widely available from most nurseries and is seen in most big gardens like RHS Wisley but it’s Sir Harold Hillier Gardens where the original plant is still growing strong