Pruning a St John’s Wort (Hypericum) can vary depending on the species you’re growing. ‘Hidcote’ should be pruned in the spring, removing any weak, old or thin growth. Shorten the remaining stems back to the base or to strong shoots. Always make your cut just above a bud. If your plant has got out of hand you can prune all the stems to ground level now - you will probably get quite vigorous new growth in response!