Acid reign on
If your soil passes the litmus test, azaleas can bring a riot of springtime colour, writes David Overend.
If you’re serious about putting some real colour into your garden, then look no further than azaleas. From late autumn to late summer, a huge range of different species and varieties are in flower, but for big bursts of flowers, the choice is greatest in spring.
Azaleas are a subset of the rhododendrons, regarded by many to be one of the most important plant families. They are a category of smaller-leaved, generally smaller and more “twiggy” shrubs.
The history of these plants is complex and fascinating and includes its fair share of Victorian derring-do. However, all that the practical gardener really needs to know is what they need to thrive.
Acid soil is a must with nearly all of these shrubs, but if you lack this, containers and raised beds can work just as well in providing the necessary conditions. Ideal soils are moist, humus-rich and acidic, with good drainage.
All azaleas are surface-rooting, which means that when planted, soil should just cover the root ball. A bonus of this is that it’s quite straightforward to move them, should you need to.
Maintenance is limited and easy. Cut off dead flowers and stalks soon after flowering, as this will stimulate new growth. Otherwise, prune lightly to maintain the desired shape.
As to the choice of species, this depends on the look you wish to create, and what will work best in your garden. Here are a few examples of outstanding performers:
■ Rhododendron “Cecile” is a vigorous deciduous azalea which achieves a height and spread of 2.2m. It produces clear, salmon-pink flowers in late spring and early summer.
■ Rhododendron “Homebush” is a compact variety with a bushy habit. It achieves a height and spread of 1.5m and in late spring produces trusses of bright pink flowers. It’s an excellent choice for container growing.
■ Rhododendron “Narcissiflorum” is a wonderful garden plant producing sweetlyscented pale yellow flowers from spring into early summer.
■ Among the evergreens, Rhododendron “Palestrina” produces delicate white flowers, while those of “Beethove” or “Vuykk’s Scarlet” are pink and crimson scarlet respectively.
■ Hardy evergreen or Japanese azaleas are some of the most colourful springflowering shrubs, all requiring acid soil and moist leafy conditions for their shallow roots. They thrive in light shade, but will tolerate full sun if their roots are consistently moist.