The climbing Morning Glory, as Ipomoea tricolor (syn. I. Rubro-caerulea) is called. Is a splendid pot plant for the cool greenhouse with its beautiful blue trumpet-shaped. Botanically it is now called Pharbitis tricolor but it is still listed by nurseries under its former name. Heavenly Blue, a bright azure blue, is the most popular of its varieties; Flying Saucers has large blue and white striped flowers; Pearly Gates is pure white; and Scarlet O’Hara dark red. The flowers themselves last only one day but there are always buds opening to provide a continuity of colour over quite a long period.
Ipomoeas are raised from seed sown in late March or early April. Place them separately in 3-in. pots of seed compost and germinate at a temperature of 16°C. (60°F.). The seed coat is rather hard, and seed germinates best if it is chipped or soaked in water for 24 hours before sowing.
The resulting seedlings should be accustomed to full light as soon as possible and should subsequently be potted on into 4-in. and 6-in. pots when they are ready for these moves, using the John Innes No. 1 Potting Compost. The growths must be given the support of canes or wires to which the stems can cling and twist themselves around, for well-grown plants can reach a height of 8 to 10 ft.
Sometimes three plants are grown in an 8-in. pot with twigs, light trellis or wire for support. These plants should have John Innes No. 2 Potting Compost.
Plants raised in the greenhouse can also be planted in a sunny position in the garden in June. Again, they must be given support, and trellis on a sunny wall would be ideal.