Gardening with Gael: Buttercup tree reminds me of my sons

28 Mar, 2022

When I say to my grandchildren that I feel a plant in a garden centre virtually asking me to take it home, they roll their eyes. “Any excuse Granny” they say. It was never more true than in Bunnings on Monday. I have transplanted some yellow and orange hibiscus above the plumbago (Yes the garden is beginning to look like an inverted Ukrainian flag). I have planned a strong showing of yellow at the approach to the house.

As we trailed up and down the aisles looking for a plumbago for Sue I spotted a plant I grew 40 years ago in my original garden. It reminds me of my sons. Cassia corymbosa ‘John Ball’, also known as a buttercup tree, starts flowering at the beginning of autumn and goes on to provide a sunny mass of flowers through to winter.

Often it began flowering on Matt’s birthday and continued through to Nick’s. I had it in full sun in a boxed-in garden bed facing north where it got all day sun. From memory, it required little care. I do remember that it grew vigorously and I needed to give it a good prune each year to stop it looking ‘leggy.’ The flowers bloom on new growth so it is a good idea to prune each year.

Buttercup trees prefer a slightly acid, free-draining soil. My original tree grew on the Tara, free-draining volcanic which was perfect. Sandy soils tend to be slightly acid as well and I will need plenty of compost to help retain some moisture. Loamy soils and peat are also ideal and they have been known to grow in clay.

There in Bunnings was a particularly robust specimen practically begging to come home with me. There was no way I could leave it there. I hadn’t planned on a double row of yellow on the bank so this plant fits well on the corner where it has plenty of room to spread. Buttercup trees generally grow about 2m x 2m, but in ideal locations can grow up to 4m.

The leaves are interesting in that they fold up at night. The flowers are a shining rich yellow with cupped petals.

My shrub will be on a bank. The recent rain has made me doubly aware of providing new plants with a ‘platform’. In most soils this is easy. Just dig into the bank a bit in order to provide a flat area. This area also collects the rain rather than it racing past taking nutrients with it. With sand there also needs to be some form of retaining. A few rocks at the back of the platform and a few at the front help prevent the rain washing the sand away. The rocks, along with plenty of mulch, stabilise the sand and would prevent the sand escaping during the recent downpours experienced. Well placed branches and sleepers also help. I love the rocks because they keep the ground damp as well.

Buttercup trees originated from South America and when in bloom will attract bees, birds and butterflies.

The buttercup tree starts flowering at the beginning of autumn and will provide a sunny mass of flowers through to winter. PHOTO/WIKIPEDIA