Description
Hydrangeas are a very popular shrub that are grown for their impressive flowers that appear in Summer, with the most synonymous with the genus being the large round flowerheads produced by Hydrangea macrophylla and Hydrangea arborescens. Hydrangea macrophylla species can have two different forms of flowers depending on the specific cultivar, they can be either mophead with the large round flowerheads, or lace cap with a much flatter profile. Both types can change colour from pink to blue flowers depending on the levels of aluminium available in the soil, and this is typically controlled by the acidity of the soil, with acidic soil leading to blue flowers and more alkaline soil causing the flowers to go pink. White varieties will remain white regardless of the soil pH.