If you had started off your cutting earlier than this time it would bloom this year. Just strike a strong ,straight ,upright cutting early enough. Take out any side shoots as soon as they form. when it reaches the height you want....stop pinching off side shoots. Support well and feed and water and enjoy your plant. If you have one in April with suitable shoots....do it then or May. Or have a look for a bought one with a strong upright habit, choose some strong shoots and see if any strike....cut just below a leaf axil. Almost any compost will do