Bring a cool change to your summer garden
Late spring is hydrangea time. With their lovely neat mounds of lush green leaves topped by clusters of little buds that grow plumper by the day, they are a highlight in semi-shaded situations from now through to the end of summer. In full bloom, the large, striking flower heads in shades of blue, purple, pink, cerise and white are gorgeous. The foliage too is lovely, with large, dark green oval leaves, often with serrated edges. The lushness of the foliage and the mostly cool tones of the flowers have a soothing effect in a summer garden.
There are more than 70 species in the hydrangea genus, including small trees and climbing varieties. But what we commonly call 'hydrangea' is usually hydrangea macrophylla, and there are more than 600 cultivars of this species alone. These are sometimes known as moptops, and they produce large heads of simple, flat four-petalled flowers. A slight variant on the moptop is the lacecap with flat flowers around the outside of the head surrounding a centre containing many tiny, intricate, lacy flowers.
Hydrangeas are an easy-care, fast-growing deciduous shrub to 1-3m. One of the very cool things about hydrangeas is that the flower colour can be somewhat variable according to soil conditions. Acidic soils will generally produce bluer flowers, whereas alkaline soils will produce pinker flowers. White varieties will tend to remain white, although they may be tinged with blue or pink as they age, depending on the soil.
Hydrangeas are long-lived and easy to grow. The ideal position is partly shaded, protected from strong winds and hot afternoon sun. Not too shady, though, or you will have beautiful leaves and few flowers. You'll need moist, well-drained soil enriched with plenty of organic matter. Use water crystals when you plant and keep the plants well mulched because they don't like to dry out. They look spectacular in pots if you can keep them really well watered. Avoid wetting the foliage as this can encourage fungal disease which you can treat with organic Eco-Fungicide.
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