Semi-ripe cuttings are taken from mid-summer until mid-autumn, when growth slows down and the stems start to harden. The base of the cutting should be hard, while the tip is still reasonably soft.
Semi-ripe cuttings taken in summer do not need bottom heat, but they do need good humidity and protection from strong sunlight. They can be rooted in pots or in the soil. They should have rooted by spring.
Rooting in the soil
Semi-ripe cuttings can be rooted in soil in a covered cold frame, low polythene tunnel or cloche or similar structure.
Cultivate the soil first, adding organic matter and fine grit or sharp sand to improve drainage. Rake it level and lightly firm, then cover the soil with a 2.5-4cm (1-11/2in) thick layer of sharp sand.
Rooting in pots
Especially when only a few cuttings are needed, root the cuttings in pots of rooting compost. Place the pot in an unheated propagator or cover it with a milky polythene bag, supported on a wire hoop or support made from split bamboo canes to keep it away from the leaves and seal around the pot with an elastic band. Place the pot in a warm, light position, but out of direct sunlight in an unheated greenhouse, cold frame or on a windowsill.