Banksia marginata [ex. Bremerton, WA]

I guarantee this Banksia is made of pure silver! Well, not quite, but it's almost as good. This species is usually a shrub to about 5 - 8' tall, but it may attain the stature of a small tree. The green leaves are comparatively small (under 2”) with light serrations, and silvery underneath. Yellow flowers may appear on tall cylindrical “cones” in winter. Silver Banksia is very easy to grow. It will be happiest in full sun on sandy or silty soil, and does not like clay or very rich soils. It is quite drought tolerant but will also not object to moderate summer irrigation. It can also be grown in a large container for many years. This plant was shared with us by Brian Brown from his garden in Bremerton, Washington, where it has remained unscathed by the severe cold events of November 2006, December 2008 and December 2009 - it's now about 10' tall. We also know that this plant is originally of Tasmanian origin, suggesting it is well adapted to a cool climate. Hardiness once established is certainly somewhere below 20 °F; hopefully, further testing will enable us to figure out just how much lower.