When autumn approaches there are several unusual plants that appear, especially in older gardens.
One of these is a peculiar semi-tropical plant that I have noticed flowering in a few places this year. Its botanical name is Clerodendrum trichotomum¸a difficult one to either remember or pronounce.
A large shrub or small tree, it usually grows to about two metres in our climate and has several different appealing features. Firstly, the foliage, which is soft and downy and has a peculiar scent. Some say it reminds them of peanut butter, but if that’s the case, I’m switching to Marmite!
The flowers are pretty – jasmine-like, pure white and sweetly scented. They are borne at the end of relatively large calyxes, which are light green during flowering but later turn red at the same time the fruit appears. These are small white berries at first, but they deepen to bright metallic blue and look very showy.
And there’s the trouble. As in so many cases of introduced plants, these berries contain lots of seeds, and this plant has such a propensity to shed them into the environment that it has been declared a noxious weed and can no longer be distributed in New Zealand.
I have always been interested in clerodendrums, mainly stemming from the exotic C. thomsoniae that we used to sell in the garden centre where I worked. This tropical climber but usually grown as a pot plant in New Zealand. It has the most amazing flowers, bright vibrant red, but popping out of large pure white calyxes.
Around here it would need to be grown inside, or perhaps on a patio and then brought inside for the winter. A big pot and some kind of climbing frame will suit this plant well, and you’ll have dramatic flowers for months at a time.
There is a hybrid of this species called ‘Delectum’, in which the calyxes are pink rather than white, and the flowers are also pink instead of red. It is relatively unusual, and can grow very vigorously, but makes a dramatic plant for the warm glasshouse, or perhaps a very warm area in a conservatory.
For those of you who like unusual plants, there is another Clerodendrum to keep an eye out for, although you will probably only see it in the heated glasshouses at botanic gardens – the tropical shrub C. speciosissimum.
The shrub, sometimes called the Java glory bower, has large, heart-shaped leaves. It covers itself with bright red flowers in summer, followed by bright blue berries. This one has proven to be a bit of a problem in the tropics, and is now a widespread garden escape, but is not known to have made its way into the wild in Aotearoa – I guess we are just too cold for it.
A couple of years ago, I was in Melbourne on a working holiday and spent a pleasant afternoon wandering around the wonderful Botanic Garden. As I meandered, I came across a blue flowering shrub I had never seen before. I looked for a label – most of the plants were well labelled – but could not see one.
I poked around the branches and could not find a tag, then swept my hand through the undergrowth, unsuccessfully looking for a label. I took some photographs, thinking I would be able to identify it once I got back to my hotel room.
I went up to the Melbourne Museum and looked through a room filled with stuffed Australian animals, ranging from kangaroos down to smaller animals, including snakes and spiders.
A mother was showing her children the exhibits and exclaiming in a strong Australian accent “This one will kill ya”, and “This one will kill ya.” I was slightly exasperated by the commentary, but when she said “This one will kill ya, and that’s why I always tell ya not to play in the long grass” it suddenly dawned on me that I should not have been scraping through the undergrowth. Imagine dying to find the name of a plant.
Chastened, I went back to my room and looked it up. I had thought it might be Clerodendrum ugandense, a plant I had read about but never seen, and it turned out to be so.
This is another shrubby plant, but the flowers are blue, with their odd shape earning the name of blue butterfly bush. It grows to about two metres and will do best in a sunny, warm spot, preferably well-drained. I am not sure how much frost it will cope with, so it probably needs to be in a place that does not get too cold in winter.
It is easily available from New Zealand nurseries and is definitely not invasive. However, it does have the added bonus of bearing lots of nectar so, as is the case with many blue flowers, it is a very popular target of honeybees.
