|When,which fertilizer, etc. to use on Nikko Blue hydrangeas? How much pruning can be done now (July 1) in zone 8a? Thanks!
|When all new growth has commenced (a few weeks after the first green buds), you should cut out -- very carefully -- the old wood from last year. It takes an acid soil to keep blue hydrangeas blue. Apply aluminum sulphate soon after new growth begins (well ahead of any flower buds). One application will be enough. Good Luck!|