Willow Bottlebrush Callistemon salignus (Melaleuca salicina)

Most people buy a bottlebrush for red flowers. The willow bottlebrush does not oblige. Its brushes are pale creamy yellow, its trunk carries white papery bark, and the display it is actually planted for is the spring flush of new growth, pink to bronze red right across the canopy against fine willow like leaves. It makes an upright small tree of around six to eight metres, taller in deep moist ground, and it is used as a street and verge tree, a windbreak line, or a tall screen over a clean trunk. Nectar feeders work the cream brushes as hard as they work the red ones.

It will not carry a dry start

This is a creek margin tree. Planted into shallow ground already full of the roots of an established gum, then left to fend for itself, it sits sparse and stunted for years, and the two features it was bought for never arrive: the canopy stays thin and the trunk never colours up to clean white bark. Give it an open position away from established root competition, water it deeply through the first two summers rather than lightly and often, and mulch a wide ring to keep grass and shrubs off the base. A tree that gets that start moves along steadily. One that does not may never catch up.

Where it will grow

It occurs naturally along creeks and swamp margins on the east coast, which explains the two traits that matter in cultivation: it copes with heavy soil and with ground that stays wet for a period, and it takes cold better than the weeping bottlebrushes do, so it suits the tablelands and cooler inland gardens as well as the coast. Give it an open aspect, modest water once established, and expect steady rather than rapid growth. As a windbreak or screen line, space plants two to three metres apart. On a verge, check the mature spread against the footpath and the kerb before you dig, and site it so the trunk stays visible, because keeping shrubs back from the base is what lets the bark do its work.

The cream one

Against Kings Park Special the difference is character more than size: that cultivar is broad, arching and bright red, while this is upright and single trunked with quiet flowers, and reads as a street tree rather than a shrub. Against the weeping bottlebrush, which shares the tolerance of damp ground, salignus holds its branches up instead of letting them fall. Nothing else in this range carries a cream brush, so if that colour is the reason you are here the decision is already made. Large specimens sit under mature trees.

Trunk and canopy

Prune straight after flowering, cutting back behind the spent brushes into leafy wood, or it thins out, goes leggy and top heavy and stops working as a screen. Where clearance under the canopy is the point, lift the lower limbs progressively over several years rather than in one cut. An older tree that has been left alone does respond to a staged reduction, but it is slow going, so the annual trim is the cheaper habit. Fertiliser is optional once the tree is away, and on a young one it is better spent on a thick mulch ring than on the bag. You will also see it listed as Melaleuca salicina since the botanists moved it across.

Choosing a size

This plant is available in 7 sizes, from 140mm up to 100L, priced from $16.95 to $649.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. The smaller pots hold younger plants that cost less each and establish quickly, which suits hedges, screens and mass planting where the plant count adds up. The larger sizes carry several more years of growth on the farm and give height and presence straight away, which is what you want for a single feature position or a screen that cannot wait. Not sure which to choose? Read our guide to planting for birds.