Sue Says
Choisya normally requires just a very light trim to keep it in good shape. Pruning Choisya is normally carried out in late spring. But as you are finding out, mature plants can become a bit unruly and hard pruning is necessary to bring them back to a manageable size. Start by taking out the oldest, woodiest stems, and then prune back the remaining stems to about 30cm (1) from the base of the plant. Dont forget to give it a good feed as well, to encourage lots of new growth. They generally respond very well to hard pruning.