Antique Heirloom varieties are grandiflora type Sweet Peas - these are the oldest sweet peas, many of which were bred at the turn of the 20th century by Henry Eckford at Wem in Shropshire.
The flowers are delicate in size, produced in great profusion, and rank among the highest scented of garden flowers. Even a single plant growing near a door scents the whole house, and they are very robust growers. The varieties come in a large range of flower types and colours. Like all flowers they benefit from a bit of TLC, but in their case that's mainly watering and keep picking the flowers!!