Bring color and charm to your space with an azalea bonsai tree, renowned for its stunning blooms and compact, untouched beauty.
The Rhododendron genus has around 1,000 species. Two of the most popular types for bonsai are the Satsuki azalea (Rhododendron indicum) and the Kurume azalea (a mix of Rhododendron kiusianum and Rhododendron kaempferi). Azalea bonsai usually bloom from September to May, then rest during the summer to grow new flower buds.
Azalea bonsai trees have dark green leaves that can vary in size and shape, depending on the type. Satsuki and Kurume azaleas are small evergreen shrubs that are great for bonsai and should be kept outside.
Azaleas grow many fine branches, creating a lovely, detailed shape. But their branches can become brittle, especially as the tree gets older, so be gentle if you’re wiring them.
Propagating an Azalea Bonsai tree
Azalea bonsai trees have dark green leaves that can vary in size and shape, depending on the type. Satsuki and Kurume azaleas are small evergreen shrubs that are great for bonsai and should be kept outside.
Azaleas grow many fine branches, creating a lovely, detailed shape. But their branches can become brittle, especially as the tree gets older, so be gentle if you’re wiring them.
Requirements for Growing an Azalea Bonsai Tree
Location
Azaleas grow best in a sunny spot, but it’s good to give them some shade during the hottest part of the summer day. When they are blooming, keep them out of heavy rain and strong sun so the flowers last longer. Healthy, grown azaleas can handle a bit of frost, but they should be protected if the temperature drops below 40°F (or -5°C).
Water
Azalea Bonsai trees should never dry out completely, but they also don’t like to stay too wet. So, it’s important to check the soil moisture often. If the soil gets too dry, place the whole pot in a bowl of water to soak it well.
Azaleas like slightly acidic soil, and hard tap water isn’t good for them. It’s best to use rainwater, a mix of rainwater and tap water, or filtered tap water.
Fertilizer
During the growing season, feed your azalea bonsai with a special azalea or rhododendron fertilizer. You can use liquid fertilizer once a week or sprinkle organic fertilizer on the soil every few weeks. Stop feeding when the tree is blooming, or use only half the usual amount.
Pruning and wiring
Azaleas are one of the few tree species that grow more strongly at the base than at the top. This makes them naturally grow into a bushy shape. When pruning, it’s best to cut the lower branches more than the ones at the top.
Azaleas can handle heavy pruning very well and can grow new shoots even from bare branches. Right after flowering, you should remove the wilted flowers and seed pods—this can be done by cutting or pinching them off by hand. This is also the best time to do any pruning or shaping because new flower buds for the next year start growing in summer. If you prune too late, the plant might not bloom the next year.
You can remove any unwanted shoots from the trunk or the base of the branches at any time of year. Major shaping is often done in spring, but that may mean skipping flowers that year. Azalea wood is brittle, so if you wire or bend the branches, be very gentle to avoid breaking them.
Repotting
Azaleas should be repotted every two years, either in spring or right after they finish flowering. Be very gentle when trimming the roots because they are thin and tangled, and can tear easily when you try to loosen them. Always use special soil made for azaleas— it must be lime-free. Pure Kanuma is a good choice for this.
Pests and Diseases
Azaleas don’t usually have many pest problems. But if the air is too dry, spider mites might show up. You can get rid of them with the right pesticide and by keeping the air more humid.
Vine weevils can chew on the leaves, and their grubs can do serious damage to the roots. You can use special pesticides or helpful nematodes to get rid of both the beetles and their grubs.
If the soil is too wet and packed down, a fungus can cause root rot. You can treat it by pouring a suitable fungicide into the soil.
Another fungus can cause leaf galls. In spring and summer, some leaves (and sometimes stems) swell up, curl, feel soft, and turn pale green. Later, they may get covered in a white powder and then turn brown and hard. This happens more often in azaleas with solid red or purple flowers, especially when the weather is very wet. The best way to deal with it is to remove the galls as soon as you see them and protect your azalea from too much rain.
