in autumn
dig a narrow trench 6 in deep
if clay sprinkle sand over bottom of trench to improve drainage
choose a ripened stem from this years growth
remove lenghts of at least 12 in cutting flush with main stem
cut off all leaves and soft growth at tip ,trim to 9 in ,make an angled cut above top bud and straight cut at base
place cuttings in trench 4-6 in apart burying 2/3 of stem
firm soil and label
next year they should grow and after leaf fall in autumn lift them,and transplant and grow on.
hope this helps and good luck and have fun
take more cuttings than you think youl need as they might not all grow
prob most will tho.