Clinton brought this lovely little tree to the February meeting to illustrate how good Australian natives are for bonsai. This is a dwarf variety and like all Banksia serrata, it has wrinkled, grey, knobbly bark and shiny green serrated leaves. Add beautiful large, yellow/ grey flowers (known as inflorescences) and what more could you want?
There are over 170 species of banksia endemic to the east coast of Australia, ranging from Queensland to Australia with out-lying populations in Tasmania and Flinders Island. This particular variety is available from Ray Nesci’s Nursery, labelled as a Cape York dwarf variety. Clinton recommends this variety for all the general banksia qualities but also because it grows more slowly than other banksia and has a ‘good and small’ leaf proportion.
Like most Australian natives, this variety likes water and full sun and will become spindly with larger leaves if sunlight is insufficient. This tree is kept in a water tray over summer. Clinton suggests repotting every year which will ‘definitely spur them on’. Do this just before spring, when the weather is mild and before the trees become active. Use a larger pot as, ‘they are not forgiving plants if they dry out’!
To get flowers, don’t prune in spring but wait six weeks or so for the flower buds to develop. Select the flowers you want to keep and don’t trim those branches. Branches that have flowered won’t grow any further so this needs to be considered in terms of the tree’s design.
A final note of caution: banksias don’t need a lot of fertiliser and are phosphorous sensitive so only ever use a native fertiliser and make sure the phosphorus is low.