About this variety
Introduced in 1898 and still the standard by which sweet pea scent is judged. 'Black Knight' is a Grandiflora, which means smaller and plainer flowers than the modern Spencers, and a fragrance those varieties largely bred out in the pursuit of size.
The colour is a deep maroon that reads as black in any shade and only shows its red in direct sun. Three or four stems in a small vase will scent a room.
Grow it as you would any sweet pea, but do not expect show-bench stems. This is a variety to grow for the nose, cut short, and put where people sit. Pick it constantly or it will set pods and stop within a fortnight.