Hydrangeas are one of the most popular garden shrubs in the UK. They are loved for their reliability & the generous amounts of colour they offer & the length of flowering time. Hydrangea ' Blue Danube' in an acidic soil will produce electric blue flowers, & if planted in Alkaline soil the flowers are pink, with flowerheads up to 20cm (8) in diameter, that will last well into autumn. Hydrangea ' Blue Danube' grows well in sun or shade & can be planted in garden borders & also look great planted in large patio & decking containers. Height & spread: 1m (39).