Balsam (Impatiens balsamina)
Extremely easy to grow and flowers over a couple of months (so you need at least 2 generations in the year). It is not very tolerant of heat and will die by April.
Because it is a vertical plant, you need to plant fairly close together. It is happy in either sun or shade. It is, however, very invasive. It has exploding seed capsules and so distributes huge numbers of seeds over several metres, but being a vertical plant, the seedlings are easily removed
Because it is a vertical plant, you need to plant fairly close together. It is happy in either sun or shade. It is, however, very invasive. It has exploding seed capsules and so distributes huge numbers of seeds over several metres, but being a vertical plant, the seedlings are easily removed