How to prune rock hyssop

Late summer to early autumn, immediately after flowering finishes. After flowering, trim the plant lightly with shears or scissors, removing the spent flower stems and up to one-quarter of the current season's growth. Do not cut into the woody base — always leave green stems below the cut.

Once annually after flowering. Rock hyssop (Hyssopus officinalis subsp. aristatus) is a compact dwarf subshrub that benefits from a light trim after flowering to keep it neat and prevent it from becoming straggly. It does not tolerate hard cutting into old wood. Clip lightly each year — it requires far less pruning than common hyssop and maintains a naturally tidy, low mound.

After flowering, trim the plant lightly with shears or scissors, removing the spent flower stems and up to one-quarter of the current season's growth. Do not cut into the woody base — always leave green stems below the cut.