Sow in pots under light cover. Transplant after last frost, 30 cm apart in all directions, or sow directly after last frost, in rows 30 cm apart. In mild climates, it is possible to sow in the open ground as early as April. Nasturtiums are very sensitive to cold; wait until the weather has warmed to transplant out. Provide a strong trellis or support for vines to climb.

One of the most beneficial plant partners for legumes, nasturtiums help to deter aphids from attacking your beans (their flowers also attract hoverflies, which eat aphids). They are often used as ‘decoy’ plants or ‘trap crops’ to lure such pests away. So if you are looking for plants that repel insects, nasturtiums should be top of your list.