Troubleshooting
Shrubby St John's Wort problems — and how to fix them
Shrubby St John's Wort (Hypericum calycinum) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Invasive spreading
Stolons spread aggressively and can swamp neighbours. Install a root barrier or site where vigorous colonising is wanted.
Hypericum rust
Orange pustules and leaf drop, common in damp seasons. Cut affected growth hard, improve airflow, and clear fallen leaves.
Tatty, leggy growth
Old growth becomes woody and sparse. Shear or mow the whole patch back hard in early spring to renew dense, fresh cover.
Poor flowering in deep shade
Tolerates shade but blooms sparsely there; move to brighter positions for maximum flower.
Prevent shrubby st john's wort problems before they start
Most shrubby st john's wort issues are care-mismatch, not bad luck. Dial in the basics:
Looking for shrubby st john's wort in general rather than its problems? Read the full shrubby st john's wort care guide — light, water, soil and feeding.
Shrubby St John's Wort problems — FAQ
Why is my shrubby st john's wort invasive spreading?
Stolons spread aggressively and can swamp neighbours. Install a root barrier or site where vigorous colonising is wanted.
Why is my shrubby st john's wort hypericum rust?
Orange pustules and leaf drop, common in damp seasons. Cut affected growth hard, improve airflow, and clear fallen leaves.
Why is my shrubby st john's wort tatty, leggy growth?
Old growth becomes woody and sparse. Shear or mow the whole patch back hard in early spring to renew dense, fresh cover.
Why is my shrubby st john's wort poor flowering in deep shade?
Tolerates shade but blooms sparsely there; move to brighter positions for maximum flower.