Table of Contents
Caring for Azalea bonsai is straightforward. Key points to remember:
- Keep the bonsai evenly moist.
- Use azalea fertilizer.
- When repotting, choose an acidic bonsai soil like Kanuma.
Stick to these basics, and Azalea bonsai becomes a beginner-friendly choice.
Satsuki azaleas (Rhododendron indicum)
These hardy outdoor bonsai trees thrive best outside. They’re popular as bonsai due to their spectacular flower displays.
Fertilizing Azalea Bonsai
We fertilize our Azalea bonsai right after they bloom, from mid-May to September, using nitrogen-rich mineral fertilizer.
When fertilizing, it’s crucial to match the bonsai fertilizer to the soil’s acidic pH value.
Use Azalea-Specific Fertilizers
Azalea-specific fertilizers are ideal. Organic options like Biogold and Hanagokoro work well too. These can be applied before flowering since they take a few weeks to be effective.
Liquid Fertilizers Work Too
Common liquid bonsai fertilizers are also suitable.
- Before flowering: Use the amount indicated on the bottle.
- After flowering (for more leaf growth): You can double the amount.
Read more about Bonsai fertilizer here
Watering Azalea Bonsai
Azalea bonsai need special care during flowering.
First off, avoid pouring water over the flowers. It’ll cause them to wither quickly.
These trees are thirsty. During flowering, submerge your azalea bonsai until air bubbles stop rising. Sometimes you’ll need to do this a few times a day.
Use lime-free water. Hard water can stunt growth and yellow the leaves. Rainwater is your best bet.
In Japan, they use Yamagoki moss on the soil surface. It helps keep the surface humid, benefiting the fine surface roots
Location
In summer, Azalea bonsai thrive best in full sun to half shade.
For the healthiest growth:
- Full sun is ideal if you can water the bonsai several times a day, especially when it’s flowering.
Overwintering
Satsuki azaleas can handle temperatures as low as -15°C if they’re in unheated foil tents.
Here’s how to ensure they survive winter:
- Cover them with bark mulch up to the first branch.
- Expect up to 50% leaf loss; this is normal and not a cause for concern.
Repotting
Repotting Timeframe
Every three to four years or when the roots fill the pot, it’s time to repot your azalea bonsai. Do this after flowering with a root cut. Given that the flowering season might end in July, and it’s hot and dry, consider repotting in spring instead. Just make sure to keep it in a frost-free spot afterwards.
Improving Soil Appearance
Kanuma soil’s yellow look can be unappealing. To fix this, top it off with a 1:1 mix of Akadama and humus.
Choosing the Right Soil
Azalea bonsai need lime-free soil. Japanese Kanuma bonsai soil is perfect. Avoid peat-containing garden mixtures, even if their pH is low. Once dry, these substrates are hard to re-wet. Skip other bonsai substrates like expanded slate. Kanuma soil provides all the nutrients a good azalea soil needs.
Extra Tips
- Azalea Bonsai Soil: Lime-free, Japanese Kanuma is the best.
- Soil Layer: Top with Akadama and humus mix for a better look.
- Repotting: Every 3-4 years, post-flowering, or in spring with frost protection.
- Avoid Peat Mixtures: They’re tough to wet again once dry.
- Skip Extra Substrates: Kanuma has everything needed.
Diseases, Pests
Pests on azalea bonsai are rare. After import, you might spot spider mites and other sucking insects. No worries, though. You can handle them with commercial agents for spider mites.
Propagation
Azaleas are a breeze to propagate from cuttings. Growing them from seeds? Not so much.
Styling
Even though they start as shrubs, you can shape them into impressive trees with cutting and wiring. Japanese bonsai nurseries show off azalea bonsai with massive trunks.
Bonsai Wiring Tips
When wiring azalea bonsai, be gentle. The wood of Satsuki azaleas is brittle and can break if bent too much.
To wire an azalea bonsai, follow these steps:
- Work slowly and carefully
- Use softer aluminum wire, not copper
- The larger diameter of aluminum wire is kinder to the thin bark
This approach prevents injury to the delicate bark of your azalea bonsai.
Using the right techniques can transform your Satsuki azaleas into stunning bonsai trees with proper care and attention.
Pruning
After your Azalea bonsai flowers, it’s time to start pruning. First, pluck off the spent flowers with your fingers. Then, get into pruning mode.
Satsuki Azaleas
These Satsuki azaleas can handle a good cut. They sprout new growth in all directions, even the odd ones. Use sharp bonsai scissors to snip off shoots that go straight up or down.
Bigger Cuts
For bigger cuts, you’ll need a concave bonsai plier since the wood is tough. Apply wound closure agent to help the wounds heal better. If you skip this, the cuts can stay visible on the smooth bark for a while.
Styles
Bicoloured Flower
Azalea bonsai look great in most styles except the broom style. They’re usually styled in the Moyogi (upright) or Shakan (slightly inclined) styles. Sometimes, you’ll see them with exposed roots. Half-cascade or cascade styles are also quite popular.
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