Morning glory Clarke’s heavenly blue
In cultivation, most are treated as perennial plants in frost-free areas and as annual plants in colder climates, but some species tolerate winter cold. There are some species which are strictly annual , producing many seeds, and some perennial species which are propagated by cuttings. Some moonflowers, which flower at night, are also in the morning glory family.
Because of their fast growth, twining habit, attractive flowers, and tolerance for poor, dry soils, some morning glories are excellent vines for creating summer shade on building walls when trellised, thus keeping the building cooler and reducing heating and cooling costs.
Popular varieties in contemporary western cultivation include ‘Sunspots’, ‘Heavenly Blue’, the moonflower, the cypress vine, and the cardinal climber. The cypress vine is a hybrid, with the cardinal climber as one parent.
Many morning glories will self-seed in the garden. They have a hard seed coat which delays germination until late spring, at which time they will grow and flower rapidly. To improve the germination of purchased seeds, soak them in a dish of warm water overnight before planting.