Semi-double blooms in soft pale mauve-pink, each petal outlined in a slightly deeper shade. It is a picotee edge rather than a stripe, subtle enough that people often do not register it until they are holding the flower.
That subtlety cuts both ways. Across a border the picotee does not read at all and you have a pleasant pale mauve cosmos. In the hand, or in a vase on a table, the detail is what lifts an ordinary bouquet into something that looks arranged. Grow it where it will be seen close to, or grow it for cutting.
Semi-double is the useful middle ground. There are enough extra petals to give the flower substance, and the centre stays open, so bees can still work it in a way they cannot work the fully double sorts. At 90 to 120cm it wants some support and a sunny open spot. It is half-hardy and flowers July to October. Keep it hungry; cosmos on fed, rich ground makes leaves instead of flowers.
