Black Eyed Susan

Water tanks are to my mind unavoidably ugly, requiring a disguise at the soonest possible opportunity. To effect this I have, as I have already mentioned, planted golden rain vine, Pyrosteria venusta and the blue sky flower vine, Thunbergia grandiflora, with as the name suggests sky blue flowers up to 5cm across. To party with these two, growing of its on volition elsewhere in the garden, I have black eyed Susan, Thunbergia alata. This vine is very easy to grow, and will start from seed. The flowers are 3cm in diameter, orange and sport a ‘black eye’ at the centre. I hope, in the company of the other two, and with a native purple convolvulus Ipomaea palmata, will all soon be romping over the water tank, keeping it cool in the summer and screening it from view by the front door.

The genus Thunbergia is comprised of some 100 species ranging in habitat from tropical Africa to tropical Asia, including India. They were named for Dr. Karl Pehr Thunberg, 1743-1822, who travelled through Batavia and Japan before returning to Sweden where he became Professor of Botany at Uppsala. Many of them produce showy flowers hanging on long racemes below the foliage. Of these I once grew the scarlet clock vine, Thunbergia coccinea a native of India and Burma (Myanmar). My vine threw itself to the top of a tea tree from where it dangled it long racemes (up to a metre long) of red flowers over the driveway. I bought it in a wee nursery in East Tamaki (no longer there) and have never seen it advertised for sale since. Another Thunbergia Lady’s slipper vine, Thunbergia mysorensis, also hangs its flowers on racemes below the canopy. The flowers are rusty red in bud and open out with reflexed petals of yellow, the whole looking very exotic indeed. There was a vine growing in the Auckland Domain at the winter gardens on the pergola adjacent to the tropical house, whether it is still there or not is doubtful as last time I was there, staff were replacing the pergola and the vines were in large piles on the ground!

Thunbergia grandiflroa var. alba, a white form of T. grandiflora, is another with flowers performing at the end of a dangling raceme. I the great fortune of finding this lovely vine recently, after only ever seeing it in a book on gardens of the tropics. This vine is destined to clothe a ragged old wattle tree. The intention is for the flowers to hang down above the heads of visitors as the wander beneath.

On the bank below this I plan to plant some nikau Rhopalostylis sapida, a couple of which I have struggling valiantly for their lives in pots on the deck. It is well time they were released into the garden! Coupled with these I think clumps of cabbage tree Cordyline australis, would work well. There are a very large number of different forms of cabbage trees available and since I plan on planting here a pink hibiscus Hibiscus X ‘Agnus Gault’ I think maybe a clump of red cabbage trees might do well along side her!