Hydrangea serrata Bluebird | Hydrangea

Flattened heads of beautiful, blue-mauve flowers last from June to September and in autumn, the pointed, mid-green leaves turn dusky red. On alkaline soils the flowers may become pink. This compact, deciduous hydrangea is perfect for small gardens in sun or partial shade. Hydrangeas give their best blue flowers on acidic soils with a pH of 5.5. When grown on neutral soil (with a pH of 7), the flowers will predominantly be pink, although you may also get blue or mauve blooms. If you want to make sure that your hydrangea has blue-toned flowers, you will need to make sure your pH does not creep above 6.5. To lower the pH on a neutral soil, you can treat it annually with aluminium salts. It's much harder however to alter the pH of limey (alkaline) soil, so it's much easier to grow white or pink hydrangeas instead.