According to the old books, blue flowered Ipomoea tricolor were in cultivation over a century ago, but those plants were very late blooming. This was sometimes the case with plants little improved over their wild forms. The Cosmos bipinnatus grown in the late nineteenth century were huge, coarse plants, tall and very late blooming. It was not until well into the twentieth century that dwarf, early-blooming forms were developed.
‘Heavenly Blue’ came into commerce as “Clark’s Early Heavenly Blue Morning Glory”. Anne Roe Robbins, in her 1949 HOW TO GROW ANNUALS points out that it was introduced before there were All American Selections awards – the point being that one would expect the best blue flowered plant we can grow easily in our gardens to have an AAS award. Her book has been reprinted by Dover; be sure to at least see the original because the Dover reprint contains revised cultivar lists.
On the street where I grew up in Silver Spring, Maryland in the 1950s we had a neighbor whose garage in many years had a glorious swag of this morning glory over the doors of the garage. I’ll bet garages all over America have been festooned similarly, even to this day. Garages, out buildings, fences, the otherwise bare, sunny façade of a building – all are ideal places for this plant. It pays to give it plenty of room: a sunny surface of several square yards is about right. When you come out in the morning and see a mass the size of a bed sheet of the intensely blue flowers you won’t regret being generous with space.