Grevillea banksii aka Banks' Grevillea

Grevillea banksii, or red silky oak, belongs to the Proteaceae family. It comes from eastern Queensland in Australia. This evergreen plant grows as a shrub or small tree. Its tree form has a slim outline. Some plants stay low and spread along the ground. This low form is rare. People grow the species in tropical and subtropical regions, both for ornament and practical uses.

The source gives a reference height of about 20 feet [6 metres]. Its broader height range is 13–33 feet [4–10 metres]. The evidence does not separate garden heights from those in the wild. It also gives no mature width. The plant keeps its leaves through the year. The supplied species account gives no detailed leaf or bark traits. A photo caption records a white-flowered form. In Java and Peninsular Malaysia, plants can bloom throughout the year. That timing should not be assumed for all climates.

In its native habitats, it grows in woodland and open forest. It often occupies flat ground with sandy soil. It also grows in heath and on rocky slopes. Records place it at elevations of 820–6,562 feet [250–2,000 metres]. Kew places it in a climate with a seasonal dry spell. The cultivation account says it grows best where rainfall is high. These records describe different aspects of its range and growing conditions.

For cultivation, give it sun and soil that drains well. It can grow in a range of soils. The account reports some frost tolerance but gives no minimum temperature. It therefore offers no firm basis for a hardiness-zone rating. Growers can raise plants from seed or cuttings. Trees can produce viable seed at three to four years old. The evidence gives no specific pest or disease problems.

People plant red silky oak for shade and as an ornamental. It also serves as a living fence and plantation windbreak. Growers use it to shelter coffee and tea crops. Its wood supplies timber and fuel. Yet it has escaped gardens and become invasive in some places. The account records invasion of native habitats in Hawaii. It lists no known food or medicinal uses. It also lists no known hazards, but gives no specific human or pet safety assessment.