Lacecap Hydrangea (syn. Blue Wave)

Hydrangea macrophylla Mariesii Perfecta

• Position: full sun or partial shade
• Soil: moist, well-drained, moderately fertile, humus-rich soil
• Rate of growth: average
• Flowering period: July and August
• Hardiness: fully hardy

  
  One of the most popular lacecap hydranges, this has flattened heads of pink to mauve flowers from July to August and coarsely toothed, glossy, dark green leaves. On alkaline soils the flowers change to lilac-blue. Like most hydrangeas, it's best in moist soil in partial shade and looks wonderful towards the back of a mixed or shrub border, particularly when planted with other hydrangeas.
  

• Garden care: Hydrangeas do not like to dry out. In dry weather, soak the roots with a hose and the plant will usually recover. Remove faded flowerheads in spring after the danger of frosts, cutting back the flowered stems to a strong pair of buds. Take out misplaced or diseased shoots. Mulch young plants with a well-rotted manure or compost in spring. Once established, remove a quarter to a third of the shoots to the base of the plant.

  
  Hydrangeas give their best blue flowers on acidic soil of pH 5.5. When grown on neutral soil, with a pH of 7, flowers will predominantly be pink, although blue or mauve blooms can also be produced. To produce blue blooms, make sure your soil is acidic with a pH of at most 6.5. To make a neutral soil acidic you can treat it annually with aluminium salts. However it's much harder to alter the pH of limey soil (alkaline), so it's easier to grow white or pink hydrangeas.