Anita Morton - Growing Gardens
Hydrangeas are an excellent flowering shrub for those damp, shady parts of the garden which can be a bit difficult. Hydrangea macrophylla is the common mop head and lace cap hydrangea, and originated in Japan, where is grows naturally as an understorey shrub in the forests. The hydrangea comes in a range of colours from pure white through to red, plus the pink/blue variable colour that changes with the soil pH.
This variability is related to the availability of aluminium flowers will be pink in alkaline soil that locks up this element, or blue in acid soils where it is freely available. Its easiest to go with the flow on our acidic soils and have the blue variety, but if pink is your thing, just lime the soil around the hydrangea each year to keep it sweet.
Hydrangeas also come in variegated-leaf varieties indeed, this is an excellent variegated plant, as the crisp contrast between green and clear white is quite striking. Like all variegated plants, they will benefit from a little morning sun to keep a good balance of green and white. In fact, while hydrangeas will be happiest in a semi-shade position, they will also grow well in sunnier spots, provided the soil is constantly moist and they are sheltered from strong sunlight by neighbouring plants. Be sure to water all your hydrangeas liberally until the rain starts this summer.
A striking combination Ive seen is the white-flowering hydrangea with black-leafed taro or elephants ear (Colocasia esculenta). Both these plants will grow and look their best if they get morning sun, but can also cope with deep shade. Hydrangeas flower on new wood, so encourage fresh shoots by pruning off the old flowers as they start to look tatty, and giving them a bit of compost or well-rotted manure to boost them along.