All sorts of easy to grow cacti all ideally suited to window sills, sun rooms or greenhouses.
Sow January to April. Sow into pots or trays of free draining, gritty compost and cover with a very fine sprinkling of silver sand. Place in a propagator or warm place, and keep at a constant temperature of between 20-25C (68-77F). After sowing, do not exclude light as this helps germination. Keep the surface of the compost moist but not waterlogged; germination can take 1-3 months and may be erratic.
Water freely and apply a balanced liquid fertiliser monthly. Keep plants dry in winter.