Azaleas come in a variety of different colours and sizes and bloom magnificently in both winter and spring so it comes as no surprise that they are one of the most popular of all garden shrubs. They’re part of the rhododendron family and there are several different types. The two most common types sold are Indicas and Kurumes. Kurumes are smaller and their foliage and flowers are also smaller. Their flowers can be double or single. Indicas are the largest and most popular variety of azalea. Here are our tips for ensuring that your azaleas go from strength to strength this Spring.
• Provide them with some shade. Azaleas grow and flower best in a semi-shade position. They won’t bloom to their full potential in total shade – so the best scenario is to give them morning sun and afternoon shade. Some varieties may be more or less tolerant of sun and shade so it’s best to consult your nursery.
• Avoid deep planting. A major cause of unhealthy plants is deep planting. It sets back the surface-rooting Azalea and can lead to root rot. Be sure to dig the planting hole twice as large as the root ball.
• Prune enthusiastically. To keep your azaleas compact, you should prune after flowering. Many grow long, spindly looking stems so if you prune regularly, this will keep them under control. Pruning any damaged branches also helps to protect the plant against weeds. Azaleas, especially the single flowering Indicas, can be taken back very low so don’t be afraid to prune!
• Fertilise well. In Spring, you should feed the azaleas after pruning with a slow release fertiliser or complete plant food. You’ll need to liquid fertilise the entire plant (foliage and roots) through the warm months as well to supplement your initial Spring feed. You’ll need to stop feeding in mid Autumn as azaleas will be slowing down their growth and getting ready for the next season’s flowering. You won’t feed them in late Autumn or Winter as you’ll have to wait until they flower. Then after that first main feed, you won’t feed them again until late Summer/early Autumn.
• Water every 2-3 days. Being shallow rooted, azaleas need to be watered regularly so they don’t dry out. Don’t water over the flowers themselves as this can cause petal blight (a fungal disease) and you will lose their lovely blooms!
• Thoroughly drain and prepare the soil. Azaleas thrive in soil that is slightly acidic and has good drainage. A pH of 4.5 to 5.8 is ideal. They look great planted en masse in a flower bed. They also do well in pots – just make sure there is a drainage hole at the bottom and use a premium potting mix.
• Look out for bugs on the leaves. Unfortunately these vibrant plants are prone to pests and diseases so if you see brown and silvery mottled leaves, the azalea lace bug has been busy. Bring a sample of your leaves to your nursery and they can advise you on the best spray to use for your particular insect problem. When your plant develops nice, fat flower buds, you will probably need to start a Bayleton spray program for petal blight, a fungal disease that affects flowers. This disease occurs when it’s wet or there’s high humidity and the flowers go all slimy and brown. If this happens, you need to remove the flowers and spray every 10 days until the end of flowering season.
• Mulch and use compost regularly. It’s important to use compost and lots of it as it absorbs excess water from the roots, keeping the plants moist but not saturated. As the weather gets warmer, it’s really important to use mulch on the surface and around the plants.