Ipomoea purpurea – Common morning glory
Ipomoea purpurea – perfect but fleeting
I have grown Ipomoea purpurea, common morning glory, for the last fifteen years, enjoying the flowers that appear each morning, watching them fade by the afternoon, only to be replaced by more fresh blooms the following day. Sometimes I’ve even counted the flowers, amazed by the huge number that have opened, but I’ve never studied them any more closely than that. Until this year!
This year I took a closer look!
How does it grow?
Although it’s described as a perennial in its native habitat, in Tropical & Subtropical America, in the UK we grow Ipomoea purpurea as an annual, sowing seed early in the year with artificial heat or waiting until spring to sow in the garden. It grows very fast once the weather warms up and soon romps up any support you provide. You can also allow it to scramble over a nearby shrub or tree. Here you can see the heart-shaped leaves, which are arranged alternately, and the hairy twining stems. The name is derived from the Greek words ips meaning worm and homoios meaning resembling, a reference, perhaps, to these stems looking like worms.
Then come the flowers
The hairy calyx has five sepals protecting the bud, which open as the bud expands. The flower is curled in a spiral and as it unfurls you get a glimpse of the colour to come. Isn’t that the most amazing and fascinating thing? Once it has unfurled you can see the five petals, which are fused together. It then expands into the funnel-shaped, rather fragile, flower in a glorious deep shade of purple that we recognize as morning glory.
Have you seen the light?
Down inside the tube of the flower, there are five stamens, which are fused to the insides of the petals, and one style, attached to the superior ovary. But, you could be forgiven for not noticing any of these features because of that amazing white light. How does that happen? It is as though there is a little lightbulb down there so bright is the glow. All summer long it never failed to amaze me.
Morning passes into afternoon
But that wonderful radiance doesn’t last long. If the day is particularly hot and sunny the flowers are fading by the afternoon. The petals fold inwards and roll up into the tube. In this state, it reminds me of lips that have just tasted a very sour lemon! Eventually, it withers completely and falls off. However, there’s a bud waiting in the wings, which will probably open the next day. On and on it goes with fresh blooms every morning throughout the summer.
Is that it or is there more?
A lot more. If you want to grow it again next year from your own seed you must wait for it to ripen. As all the flowers in a cyme die, the fruits swell. When they are mature they start to dry and go brown and once they’ve all dried it’s time to collect and store them. Left on the plant, the capsules eventually split and release their seed.
Here you can see the seed capsules in closeup. Isn’t it miraculous? The capsule, when ripe, splits to release the seed. You can see that it’s divided into three by a thin membrane, each section containing two seeds. Here is the potential for a host of blooms next year.
Of course, once you grow a plant that you like and does well for you, you want to find others to try and, with ipomoea, there are a number to choose from. There are several different colour forms of Ipomoea purpurea, but it is Ipomoea tricolor and its forms that are the most popular and widely grown in the UK.
There are lots to choose from
Here you can see Ipomoea tricolor ‘Heavenly Blue’ scrambling over a cotinus, taken at Great Dixter in East Sussex. Other varieties include ‘Flying Saucers’, ‘Pearly Gates’, ‘Crimson Rambler’, ‘Wedding Bells’, and ‘White Magic’. The marketing department has obviously had a field day with the names but you can take your pick.
Ipomoea purpurea also has a long list of varieties. ‘Grandpa Otts’ caught my eye, a very old variety with dark purple flowers. I.p. ‘Dacapo Light Blue’ with pale blue flowers and a deeper purple central star, also took my attention and was added to the mental list. ‘Kniola’s Black Night’, ‘Star of Yelta’, and ‘Carnevale di Venezia’ are other varieties you might like to try.
If it’s red you’re after then Ipomoea nil ‘Scarlet O’Hara’ might fit the bill or I. quamoclit, which has fern-like foliage and small scarlet flowers. I. alba, moonflower or belle de nuit, has large white flowers that are perfumed and bloom in the evening, but I have read that it is more difficult to grow away from the tropics because of lower temperatures and longer day length. I’d love to give it a go.
You might recognize Ipomoea lobata. It was a very popular summer climber some years ago, known then as Mina lobata. It looks nothing like morning glory, but is an ipomoea nevertheless. It has one-sided racemes of small, tubular, dark red flowers which fade to orange and then a creamy yellow and distinctive three-lobed leaves. At 5m it puts on a lot of growth given summer warmth and makes a fabulous display.
And last, but not least, Ipomoea lindheimeri. I liked the look of its pale blue flowers and the fact that it prefers good drainage and thrives on poor soils. I then realized that I recognized the name and wanted to know more. Oenothera lindheimeri (it used to be called Gaura lindheimeri) is a fabulous perennial, widely grown in the UK. Both plants are named after Ferdinand Jacob Lindheimer, and I found out more about him and these two plants on the excellent Lady Bird Johnson Wildflower Center website.
Planning for next summer
I’m really looking forward to enjoying Ipomoea purpurea again next year, but am planning to add to the display with some different varieties. I’ll source and buy the seed over winter ready to start sowing in the spring.
How to grow ipomoea in the UK
Bearing in mind where these plants come from, they need warm, sheltered conditions in the garden with fairly fertile soil and water during the summer. Seed should be sown early in a heated propagated. If this isn’t possible you can wait for the weather to warm up, but the plants won’t start blooming so early. I have seen it suggested that soaking the seed for some hours will assist germination. Young plants resent disturbance so should be pricked out and potted on with great care. They need to be hardened off before planting in the garden and given some twigs or something similar to start them climbing. Then stand back and, given a warm summer, wait for a fine display.
Let’s delve a little deeper
If, like me, your enjoyment of the plants you grow is enhanced by knowing more about them and their history, then read on and see where my delving took me.
Ipomoea is a genus with over 400 species, in the family Convolvulaceae, native to tropical regions throughout the world. The main subject of my post, Ipomoea purpurea, and the other plants I have mentioned come from Central and South America so that is the area I have concentrated on. The history of this region is a long and fascinating one but there was one topic that particularly grabbed my attention because of its connection to ipomoea.
A whole other ball game
If I can take you back to Ipomoea alba or moonflower that I mentioned earlier, then we’re in a whole other ballgame – literally!
The Mesoamerican ball game was played across the whole area for thousands of years and is surrounded by myth and legend. Archaeologists have excavated huge stone courts where the game was played and discovered many artifacts associated with it, including rubber balls, some of the earliest dating to 1600 BC. Which is where ipomoea comes in.
Ancient Mesoamerican peoples harvested latex from Castilla elastica, the indigenous rubber tree, processed it using liquid extracted from Ipomoea alba, and used it to fashion balls and other artifacts. This was over 3000 years before Charles Goodyear patented his vulcanization process in 1844. Scientists from MIT suggest that it was these ancient peoples’ control over the properties of latex and processed rubber that gave rise to the Mesoamerican ball game, which then became a central ritual element in all ancient Mesoamerican societies.
If you’d like to do your own ‘delving’, here are some of the links I found.
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