Hypericum St John’s Wort – Pruning, Winter Care and Fertilizing. Prune these shrubs in early spring before they leaf out. Remove 50% to 75% of the top of the shrub maintaining a mounded form. Remove the heaviest canes all the way to the ground.
Jan 08, Tips On St. John’s Wort Pruning: When To Cut Back St. John’s Wort. St. John’s Wort Pruning. St. John’s wort is an undemanding shrub that grows in U.S. Department of Agriculture plant hardiness zones 5 through 9.
If your shrub has fewer and fewer flowers every year, you may want to start pruning St. John’s wort. These are delightful plants to have in your garden, bright and colorful and easy-care. However. Aug 12, Pruning Saint John’s wort. Prune your Saint John’s wort at the end of winter or at the beginning of spring, before the first buds start opening up, to ensure you’ll have optimal blooming. Pruning every year isn’t necessary, but if you run the shears along the bush every 2 or 3 years, you’ll ensure your Saint John’s wort will keep a compact bearing.