When can I trim back my helianthemum plants?
Helianthemum plants can be trimmed after flowering.
They are a short lived plant so it is a good idea to take cuttings in late summer.
Take heel cuttings from non flowering shoots and root them in a propagator.
When rooted plant them up into 70mm (3”) pots and over-winter them in a cold frame.
Plant them out as replacements in April/May.