It is not really surprising that hydrangea are one of the most popular plants grown in the gardens of Donegal. Hydrangeas are incredibly easy plants to grow, are very dependable and provide unbeatable colour from midsummer right through the autumn. With a little care hydrangeas will do really well in almost any garden. They are great survivors and can often be found flowering away in neglected or overgrown gardens.
Hydrangea are available in a wide variety of colours including whites, pale yellows and the ever popular blues and pinks. While white varieties will keep their colour, the colour of other varieties may change over time depending on the type of soil they are grown in. In acidic soils (soils with a pH of 5.5 or less) hydrangeas will produce blue flowers, while plants grown in soil with a higher pH will produce pink flowers. If you really want a display of blue hydrangeas but you find that your soil is not suitable it is possible to fool these plants by adding what is known as a blueing compound to the soil around the plants. These compounds are made up of aluminum sulphate and will raise the level of acidity in the soil.
Hydrangeas come in two forms, mopheads or lacecaps. Mophead hydrangeas are probably the most popular and produce very showy, dome shaped flowers which almost cover the whole plant. Lacecap hydrangeas on the other hand produce much smaller, more elegant flowers. When the flowers on both types have faded in the late autumn they dry on the plant turning a golden brown. These faded flowers should be left on the plant over the winter as they give valuable frost protection to the new buds below and can actually be quite attractive on a winters morning when they are covered with frost.
Along with being great for the garden hydrangea can also be used very successfully as climbing plants. Like ivy climbing varieties of hydrangea produce ariel roots which cling tightly to walls without the need for support. While they can be slow at first and can take up to three years to start climbing, when they do take hold hydrangea will cover a wall very quickly. Climbing hydrangea will also thrive in light shade which make them great for covering north facing walls.