28 January 2015
Azaleas for Spring Colour
My wife was given a basket containing four indoor azaleas for Christmas - a plant that can commonly be found in garden centres in December. Unfortunately their chances of surviving for long are slim, and you would be better off buying an outdoor azalea.
A highlight of the spring garden, azaleas are loved for their masses of colourful trumpet blooms and look fantastic planted en masse, although even one of these plants grown alone in a garden will brighten the gloomiest of spring days. These acid loving plants they can be either deciduous or evergreen, with the deciduous species often having the most glorious autumn colour just before leaf fall. Technically azaleas are rhododendrons, though azaleas tend to be neater, more compact plants than their more rangy relatives, making them ideal for the smaller garden.
When considering how best to care for azaleas, you must remember that they are ericaceous plants and must be grown in acid soil. Azaleas require a pH of between 5.0 and 6.0 to thrive, so if your soil is more alkaline than this, plant your azaleas in containers using ericaceous compost.
Azaleas are happiest in a moist but well-drained, humus-rich soil in sheltered, dappled shade, so avoid the deep, dry shade beneath trees, any frost pockets and anywhere that gets the morning sun, as this may damage their delicate flowers.
When planting azaleas, fill the planting hole with plenty of rich, neutral or acidic organic matter such as leafmould, composted bark or pine needles. Azaleas are shallow rooting plants and prefer their roots just covered, so don't plant too deeply.
Once established, they are easy plants to care for. They appreciate a generous mulch each spring, and keep on top of deadheading to encourage new growth and further flowering next year. When flowering is finished, feed plants with a slow release ericaceous plant food. Regular pruning shouldn't be required but azaleas can be cut back hard if they start to lose shape and get straggly. Most deciduous azaleas in particular will respond well to this treatment.
If you need to grow your azaleas in pots, choose wide containers, standing them on pot feet to ensure good drainage. Ceramic or terracotta pots will keep the roots slightly warmer than plastic pots. Preferably plant in a soil based ericaceous compost, as these have a better structure than soilless ones, supporting plant growth for much longer and making watering and feeding easier. If you have to use a soilless ericaceous compost, help your azaleas by repotting them every other spring into fresh compost. Place container-grown azaleas in a frost-free, shady spot on the patio and water them regularly in summer, ideally with rainwater which is less alkaline than tap water. However, if your water butt is empty in a dry summer, don't worry as a month or two of tap water won't cause too much harm.
You can take azalea cuttings during the summer months. Take young shoots from this season's growth which are approximately two to three inches long and insert them around the sides of a three/five inch pot of ericaceous compost, after first dipping them in rooting compound. Covering the pot with a clear polythene bag will provide the required humid conditions. Keep the cuttings in a sheltered spot in the garden out of direct sunlight and don't allow them to dry out. You will have more success with evergreen azaleas than with the deciduous varieties.
Remember - an azalea is not just for Christmas.