Ipomoea nil, the Japanese Morning Glory is one of the traditional horticultural flowers in Japan. It is known as ‘Asagao’ in Japan, where it has been cultivated as an attractive ornamental plant for centuries. It is one of the most prolific and showy of all Morning Glories.
Ipomoea nil 'Kikyozaki', the Star Morning Glory produces blooms with a unique star shape. The exceptionally large blooms are 12 to 15cm (5 to 6in) wide, in a bright mix of colours, many are semi-double and each bloom has a contrasting white edge.
This extremely carefree and free-blooming, annual climbing vine will grow to around 180 to 250cm (6 to 8ft) tall. It will bloom early and load itself with masses of attractive star shaped flowers all summer long.
Each flower opens in the early morning and lasts for only one day; to be replaced each morning by fresh blossoms.
Choose a sunny position with moist soil, they cannot grow or bloom properly in the shade. The seed coating is rather hard, and it will hasten germination if you stand the seeds in tepid water for a day or two before sowing.
Sowing: Sow indoors in late winter, or outdoors in early spring
Sow indoors in early spring no sooner than three to four weeks before the last expected frosts, and four weeks before you plan to plant them outside. Alternatively, the seed can also be sown directly where they are to flower once all risk of frosts has passed. Keep soil moist during germination. Germination will take place in 5 to 14 days
Sow into individual pots or trays of seed compost. Paper or peat pots are preferable. Use well drained soil and cover to a depth of 3mm (1/8in). Maintain a temperature of around 20°C and keep compost moist.
Plants are extremely resentful of root disturbance, even when they are quite small, and should be potted up almost as soon as they germinate. Prick out to individual pots, transplant into 7.5cm (3in) pots or trays.
Gradually acclimatise to outdoor conditions for 10 to 15 days before planting out in growing position after the last expected frosts. Space 15cm (6in) apart. Consider giving them some protection such as a cloche until they are growing away actively.
Sow once the soil has warmer and all risk of frost has passed. Prepare the ground well and rake to a fine tilth. If sowing more than one annual in the same bed, mark the sowing areas with a ring of sand and label. Sow 1mm (1/18th in) deep in rows 7cm (3in) apart. Sow seed sparingly or they will choke out other seedlings.
The seedlings will appear in rows approx three to four weeks after planting and can be easily told from nearby weed seedlings. Thin the seedlings out so they are finally 30cm (12in) apart. Carefully replant thinned plants.
Ipomoea nil needs a sunny position for best flowering, the plants can grow to a height of 120 to 180cm (4 to 6ft) and will require the support of a trellis or canes.
Ipomoea is quite happy to be grown in a container, as long as due care is taken with watering and feeding. In hot climates provide a saucer under the container to maximise the water available to the plant. The size of the container will determine the ultimate size of the plant. A larger pot will need a trellis as a larger plant will be able to be grown.
Remove spent flowers to encourage prolific blooming. Plants will self sow in the right conditions, remove spent flowers or collect dried seed pods if you do not wish to have volunteer seedlings next year.
Clambering up Trellis and Obelisks. Also useful for Containers and Tubs.
The seeds of Ipomoea are one of the easiest for gardeners to harvest themselves for sowing the following year.
Soon after the petals fade from the flowers, you'll notice the seed pods begin to swell. Wait until the seed pods turn brown and begin to dry. Ripe seeds turn black and hard once they are ready to be harvested and the rounded brown pod turns crisp. If you squeeze a seed pod and it is ready to release the seeds, it will crumble in your hands. If you apply pressure to a seed pod that isn't quite ready it may be soft or pliable and won't break apart. Eventually the pod will dry out and open naturally to release the seeds, they will self sow themselves and begin growing into plants the following spring.
Squeeze the black seeds from their pods and place them into a brown paper bag or envelope. Do not forget to label and date them and store somewhere cool and dry for next year. By the time you have finished you will have shelves stuffed with the makings of next year’s garden.
Note that seeds of Ipomoea along with many other species, can be harmful if eaten especially if eaten in quantity. Store seeds somewhere cool and dry and always keep them safely out of reach from both children and pets.
The genus Ipomoea, with over 500 species, is the largest genus in the family Convolvulaceae. The genus occurs throughout the tropical and subtropical regions of the world, and comprises annual and perennial herbaceous plants, vines, shrubs and small trees. Most of the species are twining climbing plants.
Ipomoea hederacea is this species is the most closely related to Ipomoea nil. Having originated in tropical portions of the Americas, it is now distributed in many parts of the world. Ipomoea nil, is thought to have been introduced to Japan from China, probably in the Nara era, judging by old descriptions found in herbal documents.
Kaempfer, the German naturalist stayed in Japan for two years from 1690, observed Japanese plants precisely and drew their figures. By his illustrations, representative plants of Japan were introduced to Europe. The fifth volume of Amoenitatum Exoticarum (Kaikoku-kikan), described after Kaempfer's return to Europe, includes Catalogus Plantarum Japonicarum (Nihon-shokubutu-si) (1712), in which he made simple mention of a lot of Japanese plants. Kaempfer described one of the items he observed as 'Kingo, vulgo Asagawo'.
Although he had no illustrations of the plant, this item described the morning glory clearly, indicating that documentation of the morning glory had reached Europe by the beginning of the 18th century. It is said that Kaempfer investigated Japanese plants by referring to Kinmou-sui (1666), a catalog by Tekisai Nakamura. In the herb flower class of this book, we find the following explanation: "Kengo is a flower of Asagao. The name of its seed is Kengoshi. The name of its vine is Kuji-sou". Accompanying this description is an illustration of the morning glory climbing up and twisting around a fence. Kaempfer probably observed the morning glory by referring to this figure
Ipomoea is from the Greek ips meaning ‘a worm’ and homoios meaning ‘resembling’ thus 'like a worm,' referring to the twining habit of the plant's growth
The species name nil is thought to be from the Arabic name for this species of morning glory.
Many Ipomoea species are known as Morning Glory, a name shared with some other related genera. It is the common name for over 1,000 species of flowering plants in the family Convolvulaceae. The name of Morning Glory refers to the plants habit of opening its new blooms at the beginning of each day.
Ipomoea is a member of the Convolvulus family, pronounced kon-volv-yoo-lus is taken from the Latin convolvere, meaning to twine around.
Academic names of Ipomoea nil:
A meeting on the "Status and future of the study of the morning glory" was held at the suggestion of Professor Shigeru Iida of the National Institute for Basic Biology. The meeting took place in the Okazaki conference center in December 1999. At that meeting Yoshiaki Yoneda gave a lecture on "the morning glory and its closely related species". This lecture's principal concern was the academic names of the morning glory and related species, and changes in those names.
Though one variety of Convolvulus hederaceus in the first edition (1753) of Linnaeus's Species Plantarum was assumed to correspond to Ipomoea nil, in the second edition (1763), the academic name of Convolvulus nil L. to Ipomoea nil was first recorded, as was that of Convolvulus purpureus L. to Ipomoea purpurea. Linnaeus mentioned Ipomoea nil's habitat was North America.
As the Convolvulus of Linnaeus was recognised to have considerably heterogeneous species by later taxonomic studies, the genus Calystegia was newly proposed and some species included in Convolvulus were moved to Ipomoea or to the new Calystegia. Roth moved Convolvulus nil L. and Convolvulus purpureus L. into genus Ipomoea in 1797. Thus the name of the morning glory became Ipomoea nil (L.) Roth.
- Additional Information
Average Seed Count 18 seeds Family Convolvulaceae Genus Ipomoea Species nil Cultivar Murasaki Kikyozaki Synonym Pharbitis nil, Convolvulus nil Common Name Asagao, Japanese Morning Glory Other Common Names Imperial Morning Glory Hardiness Hardy Annual Flowers Cobalt-blue Natural Flower Time June to September Height 180 to 250cm (6 to 8ft) Spread 30cm (12in) Position Full Sun Germination 5 to 21 days Notes Very easy to grow. Vine/Climber