How to Prune giant hyssop 'Blackadder'?
Trim back stems in late autumn to reduce windrock. Prune flowered stems back in spring
giant hyssop 'Blackadder' · Agastache 'Blackadder'
Grow in well-drained fertile soil in full sun. Excellent drainage is especially important during the winter months. It can suffer during cold wet winters
Trim back stems in late autumn to reduce windrock. Prune flowered stems back in spring