Ipomoea : Greenhouse Plants
C – cool, minimum of 7°C (45°F) / W – warm, minimum of 13°C (55°F) / T – tropical, minimum of 18°C (65°F)
This name automatically calls to mind the Morning Glory which is the name given to Ipomoea acuminata, I. purpurea as well as I. tricolor (which are sometimes given the generic name of Convolvulus or Pharbitis). These are easily grown outside during summer but have to be treated as. I would definitely grow I. acuminata (I. Learii), the Blue Dawn Flower from tropical America, in the greenhouse. This is an evergreen perennial climbing species which becomes quite woody at the base with age. The flowers are produced in profusion between June and October and are a glorious blue turning pinkish with age. Grown in the warm house it will become a large plant which can be cut down if it becomes tatty or has suffered from red spider mite. It can also be kept in a cool house where it will tend to die down each autumn with the cold but grow back again and flower in the following year. Plants can be pot grown but are best planted out if this is possible. I. Batatas from the East Indies is the Sweet Potato which does best in tropical conditions. As a straight species it is hardly decorative but if you can get hold of I. b. ‘Rudolph Rhoers’ this is a fine foliage plant with purple leaves. It is best to soak seed for 24 hours before sowing; germination is then usually very good at 18-21°C (65-70°F). Perennial species can be propagated by and, of course, the Sweet Potato can be propagated by taking small tubers off the main plant at potting time.