Thunbergias grow on you…
Posted on | August 21, 2009 | 8 Comments
It’s already the third week of August and the evenings are drawing in fast, but thankfully many plants are only just coming to bloom or are now at their best. Before writing an article I like to have a slow meander around the garden to see what catches my eye. One such family of plants that are flowering to perfection at this time of year are the Thunbergias, plants I have adored since a boy. I remember buying some Thunbegia alata seeds, more commonly known as ‘Black eyed Susan’. I just adored its intense orange flowers with a deep, dark throat – so alluring. They were among the first seeds I bought from Thompson and Morgan when their catalogue had no pictures or descriptions with a yellow cover – anyone remember their 60s catalogue?
I still grow this easy annual to this day in two containers either side of the front door of my house in 12ins (30cm)terracotta pots with a wigwam of three canes about 5 feet (1.5m) tall with a scaffolding of string surrounding the canes for support. The seeds are planted in mid April when the days are longer and the sun is stronger after the dull days of winter – planting the seeds too early makes the young plants stretched and week (Etiolation). They are grown in plastic trays with individual cells so they have little root disturbance when planted out, usually about five plants per pot depending on size. They are rapid growers, reaching the top of the canes by July. The stems that stray are gently pushed back into the wigwam, where they soon twist around each other, forming a very attractive shape tightly packed with foliage. The flowers appear fairly early on in their growth but reach a crescendo at this time of year. If you want continuous flowers it is advisable to pinch out the dying flowers before they go to seed. In saying that though, they produce seed very easily, so let a few flowers go to seed so you have a supply for the following year.
Thunbergia is in a genus of about one hundred species of annuals, evergreen perennials, climbers and a few shrubs, found growing in woodlands or rocky areas, climbing through trees and shrubs in their native habitats of Tropical and Southern Africa, Madagascar and subtropical to tropical parts of Asia.
The most commonly available and most well known is Thunbergia alata which grows up to about 6ft (2m) in our climate with triangular, pointed, toothed, mid-green leaves. The whole plant is covered from summer to autumn with masses of solitary five petalled flowers which are normally bright orange, yellow or white, either with or without a dark blackish brown centre, up to 4cm across.
Thunbergia alata ‘Beauty Spot’ is a range by Thompson and Morgan with three of the most gorgeous and delectable Black-Eyed Susan’s; orange, vanilla and pure white, all with a dark beauty spot. ‘Salmon Shades’ are very attractive, in varying shades of soft salmon, each with a distinct central black eye. Thunbegia alata ‘Superstar Orange’ is a spectacular bright orange, almost day glow Black-Eyed Susan with the largest flowers in the range.
Another Thunbergia I like growing here at the Exotic Garden is Thunbergia battiscombei, more commonly known as ‘Blue Boy’ or ‘Clock Vine’. It is a stunning perennial that is always popular with visitors to the garden. It is a herbaceous plant, dying down in the autumn then returning again in mid spring, then rapidly growing to about three feet tall, forming a loosely symmetrical mound of foliage. The light green herbaceous stems hold large 5-7 in (12.7-17.8 cm) heart shaped leaves. These are bright green, smooth edged and arranged oppositely along the stems. From the axils (where the leaf attaches to the stem) arise racemes (clusters) of interesting 1in (2.5 cm) long hairy greenish-white flower buds. From these emerge the most intense blue-purple trumpet shaped flowers that create such a stunning sight against the handsome foliage that seem to glow in the evening light.
Thunbergia gregorii or ‘Orange Clock Vine’ is another perennial form and well worth growing, though it douse need to be protected from winter frost, so I grow this delightful evergreen Thunbegia in a container that can be overwintered frost free at around 41F (5C), though with a heavy mulch it might be worth trying in a sheltered well drained situation. It is an evergreen vine that grows to 8-10 ft (2.5 -3.5m) tall or if left without support can become an extensive groundcover in warmer countries, but here more like three feet. This delightful plant has bright, intense, almost day glow orange flowers. It blooms year-round in coastal California gardens and in Madeira, though it still performs well here for the summer months.
There are two species that I would dearly love to grow in the garden which can get absolutely enormous, but unfortunately they can only be grown in conservatories in this county – Thunbergia mysorensis and Thunbergia grandiflora. I am mentioning them here because I think they are absolutely astonishing plants that I always look out for when travelling in the tropics.
Thunbergia mysorensis or ‘Clock Vine’, is a woody-stemmed, evergreen climbing plant from India, in fact the name, mysorensis is derived from the city of Mysore in southern India. This spectacular vine often reaches 20 feet (6 metres) in warm countries and has narrow, glossy, dark leaves from 5-6ins (15–16cm) long. The flowers are formed on long pendant chains 3ft (1m) or more long. The individual flowers are brownish-red with a striking yellow centre, blooming from spring to autumn. I remember walking through a curtain of many racemes of this wonderful Thunbegia in a garden in southern India.
The last Thunbegia I am mentioning is Thunbergia grandiflora, a staggeringly beautiful plant that from a distance looks like a morning glory though on closer inspection is very different indeed. The tubular flowers of the ‘Sky Flower Vine’ are about 3 in (7.6 cm) long, and are borne in drooping clusters that can be 6ft (2m) or more long. The most commonly seen varieties are sky blue to light violet although there is a white flowered version as well. The leaves are quite leathery and have a distinctive elongated heart shape. The plant grows fast in warm climates; in fact I have seen this magnificent Thunbergia covering large trees in the Caribbean, looking absolutely fabulous against the tropical sky.
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8 Responses to “Thunbergias grow on you…”
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August 21st, 2009 @ 5:24 pm
The Thunbergia mysorensis is absolutely stunning. It seems like you’ll have to invest in a hothouse!
August 28th, 2009 @ 2:54 am
Hmmmmmm just seen the feature on countrywise. Methinks you are going to be packed for the rest of the summer.
August 29th, 2009 @ 3:49 pm
Lovely pictures Will and I will get to see your garden soon!
August 30th, 2009 @ 1:24 pm
what a fantastic post on thunbergias. we grow normally 3 of them. the yellow one with small flowers. blue one with large flowers and orange one which is not very common. you can see the pics of blue thunbergia on my blog as well.
September 1st, 2009 @ 2:09 pm
Beautiful photos. Found you on the home page of blotanical, in the featured spot. Glad I visited.
September 10th, 2009 @ 7:55 pm
Hiya, I love looking at your blog. The garden is inspirational, its amazing what we can get away with growing in this country. Have you seen the Thunbergia mysorensis in the Cambridge university botanic garden?. Or for that matter the Strongylodon macrobotrys, when I was at uni I regularly took photos in garden and can tell you they are breathtaking. I have a few on my blog.
Beautiful photos,Im now a follower of your blog.
September 10th, 2009 @ 7:56 pm
Hiya, I love looking at your blog. The garden is inspirational, its amazing what we can get away with growing in this country. Have you seen the Thunbergia mysorensis in the Cambridge university botanic garden?. Or for that matter the Strongylodon macrobotrys, when I was at uni I regularly took photos in garden and can tell you they are breathtaking. I have a few on my blog.
Beautiful photos,Im now a follower of your blog thanks
September 16th, 2009 @ 11:36 am
Hi Will,
Just to say thank you for a lovely afternoon in your garden, and really enjoyed our chat.
The plants travelled back to Cornwall well!