How to Fertilize Geranium pratense 'Boom Chocolatta'?
Use a balanced liquid fertilizer monthly during the spring and summer.

Geranium pratense 'Boom Chocolatta' · Geranium pratense 'Boom Chocolatta'
Thrives in moderately fertile, well-drained soil in sun or partial shade, but will tolerate most soils and positions unless waterlogged
Use a balanced liquid fertilizer monthly during the spring and summer.