Hydrangea macrophylla Freudenstein D

Hydrangea macrophylla 'Freundenstein' has both an imposing and romantically charming flowering. Its large round inflorescences, which can exceed 20cm (8in) in diameter, take on a bluish-purple hue in acidic soil, while they are a bright pink in neutral soil. It forms a compact, medium-sized bush with sturdy stems that support the inflorescences well, allowing for the creation of beautiful dried flower bouquets. Hardy, it should be placed in a semi-shaded position in non-calcareous soil. It is easy to grow, requiring only an annual pruning in spring and watering in summer to keep the soil moist.

'Freundenstein' is a Swiss variety that appeared on the market in 1966, and is credited to the breeder W. Preisig, head of cultivation and selection at Haller Nurseries in Brugg. This prolific breeder, one of the three Swiss specialists, gave birth to no less than 32 cultivars from 1960 to 1986! It is a medium-sized bush, reaching a maximum height of 1.2 to 1.5m (4 to 5ft) in all directions. Compact, it forms a beautiful regular tuft with dark green foliage with toothed edges. Its inflorescences appear in July and last until September. Its regular round heads consist of flowers with 4 sepals, which vary in colour depending on the acidity of the soil. If the soil is highly acidic, the inflorescences will take on a bluish-purple hue, with a deliciously old-fashioned charm. In neutral or slightly alkaline soil, they will be a vibrant pink.

Like all hydrangeas, it is not a strictly ericaceous plant. It prefers neutral to acidic soils. A semi-shaded to shaded exposure in a warm climate will suit it well, as well as watering in summer because it does not like dryness (of the soil and atmosphere), which can cause its leaves to wilt. Care consists of an annual pruning in spring, before the new leaves emerge. It is very hardy (around -17°C (1.4°F), although severe frosts can damage the tips of the branches. However, they easily grow back after pruning in spring). Easy to grow, it can live for a very long time. It can be planted in a container to decorate a shady corner of a terrace. In this case, special attention should be paid to watering to prevent the substrate from drying out, and a potash-based fertiliser should be applied before flowering to promote it. A thick terracotta pot would be well suited. If using a plastic container, choose one with a "double skin", meaning 2 walls separated by an air gap, providing insulation, which prevents the soil from getting too hot and therefore the roots in summer, and also limits the effect of frost in winter. Use a soil mix for ericaceous plants, adding a little compost.

When planted in the garden, this small hydrangea will blend well with other romantically styled shrubs in acidic soil. The splendid Magnolia stellata with its pure white star-shaped flowers appearing early in the season will extend the flowering season of your flower bed. Enkianthus campanulatus or Campanulate Andromeda will then take over with its small light pink bells, which will then give way to the beautiful inflorescences of our hydrangea. In neutral soil, your hydrangea will display vibrant pink flowers, which will happily coexist with other bright blooms. The superb Cornus kousa 'Scarlet Fire', a dogwood with large pink bracts, will precede 'Freudenstein', but its large decorative round fuchsia berries will accompany its summer flowering. And to compete with its large spherical inflorescences, choose from the many varieties of Crape Myrtle, or Lagerstroemia, another summer star!

Note: The colour of the flowers of macrophylla hydrangeas varies depending on the soil pH. Traditionally blue varieties turn pink in neutral or alkaline soil. To maintain a beautiful blue colour, mix ericaceous soil with your garden soil and apply aluminium sulphate (slate contains it) or alum stone every spring.