Hydrangea is a deciduous shrub that can suit any type of garden. The Hydrangea magrophylla varieties are divided into 2 groups: 'Lacecaps' - that have flattened flowerheads with small fertile flowers in the center, surrounded by larger sterile flowers, and 'Hortensias' - that have spherical flowerheads of large sterile flowers.
The color of the flowers is directly dependant upon the amount of aluminium available in the soil for absorption. This is principally determined by the degree of acidity in the soil, so acid soils with a pH of less than 5.5 will produce blue flowers and a alkaline soil with a pH greater than 5.5 will produce pink flowers. White or orange flowers are not affected by pH.
They flower form from mid to late summer and the dead flowers of both Hortensias and Lacecaps become very attractive in autumn and can be used in dried flowers arrangements. They are excellent plants for planting in a shrub border, in a group planting or in containers for a beautiful terrace display. They are fully hardy to frost hardy, so if temperatures go below -15 Celsius degrees they may damage the new growth.
Hydrangeas prefer moist but well-drained soil, humus rich, moderately fertile in a place with sun or partial shade but well sheltered from cold, drying winter winds.
If you want to propagate Hydrangea you should root softwood cuttings from spring to early summer or hardwood cuttings in winter. In spring, take stem-tip cuttings of young, non-flowering shoots of about 8-10 cm long, with 3-5 pairs of leaves. Remove the leaves at the base and tip and cut across in half the remaining leaves. Insert the cuttings into prepared pots with a mixture of peat-free compost and perlite or vermiculite, at the edges of the pot, making sure that the leaves do not touch each other. Water well the cuttings with a fungicidal solution and place them in a propagator or in place with a constant temperature of 18-21 Celsius degrees (64-70 F).
After the cuttings have rooted, remove them from the pot, gently tease them apart and plant them individually in pots, then water well and place them in a shaded position until they will be well established.
A good tip for a rich flowering: never prune Hydrangeas in spring because this can lead to a year without flowers.