How to Prune commonName:"alternate-leaved butterfly bush 'Argentea'"?
Cut flowered growth back to strong young shoots below, removing up to a fifth of old stems near the base each year. Prune immediately after flowering.

commonName:"alternate-leaved butterfly bush 'Argentea'" · Buddleja alternifolia 'Argentea'
Grow in well-drained soil in full sun. See buddleja cultivation for more detailed advice
Cut flowered growth back to strong young shoots below, removing up to a fifth of old stems near the base each year. Prune immediately after flowering.