Hydrangeas are fantastic plants for shady parts of your garden. They come in a wide range of colours from white to pinks, blues, purples and even bi-colours. They are also really easy to grow. While they tolerate full sun they prefer semi-shade and fertile, moist but well-drained soil.
The flower colour of a hydrangea will change with the soil pH. Acidic soil with a pH between 5-5.5 will make blue flowers and alkaline soil with a pH between 6.5-7.5 will make pink and red flowers. White hydrangeas however are not affected by the level of pH in the soil.
Hydrangeas are very easy to propagate. You just need to find the variety that you like in your friend's garden, select a non-flowering shoot tip, cut just above a node and trim it up. The roots will emerge from the node, Take a couple of leaves off and in order to limit water loss cut the top foliage in half and dip the end in root promoting hormone jelly or powder for a couple of seconds.
Finally place into a well drained potting mix, put it in a shady position in the garden and stand back.
The major problem you are likely to encounter is Powdery Mildew which is favoured by overly humid weather. This can be easily overcome by either pruning off the affected foliage or dusting it with a bit of sulphur.
The hydrangea is a truly versatile plant.