When I was first learning gardening there were about five shrubs you would be able to guarantee most New Zealand gardens would contain – a lemon tree, a Photinia ‘Red Robin’, the ubiquitous Daphne odora, a purple Ake ake, Dodonaea viscosa 'Purpurea' and the glorious bright red Australian bottlebrush, Callistemon citrinus ‘Splendens’.
The others all had their good points, but it was the bottlebrush, hanging over our fence line from the neighbours, that intrigued me, with its flaming red flowers, usually covered with bees, and then it’s strange small nut-like seed capsules hanging grimly to the gently decumbent branches, their maturation seemingly taking years. What fun it was for my brothers and I to roughly strip these seedpods off and throw them at each other, and other neighbourhood kids!
The common name for this popular and hardy shrub derives from its floral pattern – a bunch of bright stamen that spring outwards from the entire circumference of the branches holding them, giving a cylindrical flower that puts on an amazing floral display each spring.
The most commonly grown bottlebrushes are generally members of the Callistemon genus, although that can be misleading, as some botanists like to put all these into the wider Melaleuca genus, which also has many botttlebrushed flowers. There are about 35 species of Callistemon in Australia, members of the wider Myrtle family that includes obvious relatives like Australia gums and New Zealand pohutukawas. They are usually found in the eastern states, and generally grow in quite moist areas, so are best grown in similar conditions in New Zealand gardens.
The old ‘Splendens’ variety that I knew so well is still available, and is good if you have a big shrubbery, and if you like tending your plants a little. If left to its own devises the shrub will grow into a small tree, with a rather ungainly habit – the bottom will open up and the branches will all hang awkwardly. On the other hand, if you prune it regularly, you will have a compact growing shrub that will take many years to reach two metres, and will reward you with a spectacular show in the spring.
Perhaps the best known variety in New Zealand today is the much smaller growing ‘Little John’. This is a hybrid of C. viminalis, the other parent being unknown, and features lovely blue-green foliage and deep red flowers. The flowers can be relied on to bloom for Christmas each year.
Red is not the only colour available in these reliable Australian shrubs – colours range from white through yellowish-green, mauve and pink. ‘Reeve’s Pink’ is quite a popular variety, perhaps not quite as hardy as the two above, but still perfectly fine in a warm spot in our climate. Even better, in my opinion, is a seedling raised from ‘Reeve’s Pink’ – ‘Mauve Mist’, which was selected from about 300 that were raised. It forms a dense shrub to a height of about two meters with an equal or slightly wider spread. The new tip growth is pink and densely covered with silky hairs and the flowers, which are produced in usual botttlebrush fashion, are pinkish mauve and about 70mm long by about 50mm wide and will be carried as late as Christmas.
Among other forms available in New Zealand are the pink ‘John Mashlan’, which can be planted as a low hedge if kept trimmed; ‘Kings Park Special’ which is another bright red form and very hardy; ‘Captain Cook’; which has orange/red flowers, and ‘Rocky Rambler’ which is a new semi-prostrate form with smaller light green leaves and reduced flowers.
Perhaps the most unusual variety is one released a couple of years ago and heavily promoted as a hedge plant – ‘Great Balls of Fire’. Despite its name, it does not have red flowers, the bottlebrushes being white in this case, but it is primarily marketed as a great hedging plant, mainly grown for the extremely pretty flush of pink when the foliage is new.