This grower is sure of this plant identification.
Have a quantity of Ipomoea tricolor 'Grandpa Ott' seed, they are a predominately purple colour, easy to grow, mine had leaf of 3 inches+ and reached the top of 8 foot obelisk.
Ipomoea genus (Morning glory). This genus consists of about 500 species of creepers, evergreen shrubs, perennials and annuals; most have a twining habit and masses of funnel-shaped, fragrant flowers. They are half hardy to frost tender, min 7-10C. Grow in humus-rich, well drained soil in full light. Support will be needed.
Support is needed. Thin out or cut back congested growth in spring.
Suitable for coastal conditions.