The Bonsai Journey™ | ROUGE ‘N’ LOVE
How to Grow Japanese Maple from Seed
Acer palmatum
From a tiny seed to a tree of extraordinary character.
Japanese Maple is one of the most admired trees in bonsai, celebrated for its distinctive hand-shaped leaves, delicate branching, and beautiful seasonal colours. Its foliage can change from fresh green to shades of yellow, orange, and red, giving the tree a unique character throughout the year.
Growing Japanese Maple from seed requires patience, particularly because the seeds need special preparation before planting. This guide takes you through each stage, from cold stratification to nurturing your young tree.
01 — MEET YOUR TREE
Japanese Maple (Acer palmatum) is native to China, Japan, and Korea. Its name refers to the hand-like shape of its five-lobed leaves. It is admired for its seasonal foliage, graceful branching, and ability to develop into an elegant bonsai.
New shoots can display shades ranging from yellow and orange to red, while autumn colours can be equally striking. The bark of young trees is often green or reddish, gradually becoming grey or brown as the tree matures.
Japanese Maples are generally slow to moderate growers. Their gradual development makes them well suited to the patient practice of bonsai, where the tree is shaped and maintained over time.
In nature, Japanese Maple can grow approximately 4.6–7.6 metres tall. When grown as a bonsai, its size and form can be shaped over time through appropriate pruning, root care, and cultivation.
02 — BEFORE YOU BEGIN
Before You Begin
Your Bonsai Journey™ kit includes the following items:
- Bonsai Seeds in Four Varieties, including Your Japanese Maple Seeds
- Four Biodegradable Peat Pots
- Coco Coir Growing Block
- Four Transparent Propagation Bags
- Bonsai Planting Tools
- Bonsai Pruning Scissors
- Bonsai Training Wire
- Four Botanical Plant Markers
- Three Mini Fertilizers
- The Bonsai Journey™ — Botanical Notes
Everything included to begin your bonsai growing journey.
You will also need a small container for soaking the seeds, warm water, a clean paper towel, a resealable plastic bag, and access to a refrigerator for cold stratification.
When to Start Growing
Spring generally offers favourable conditions for seed germination. However, you can also start your seeds indoors at other times of the year if you can maintain suitable light, temperature, and moisture conditions.
03 — PREPARE YOUR SEEDS
Prepare Your Seeds
Step 1 — Soak the Seeds
Place the seeds in warm water and leave them to soak for 24–48 hours. Use warm rather than hot water, and follow the recommended soaking period.
Helpful Tip: If possible, refresh the warm water every few hours to help maintain its warmth. This is optional.
Step 2 — Prepare for Cold Stratification
Remove the seeds from the water and place them on a damp paper towel. Fold the towel over two or three times to cover the seeds. It should be damp, not dripping wet.
Step 3 — Seal and Refrigerate
Place the folded paper towel containing the seeds inside a resealable zip-lock bag.
Put the bag in the refrigerator for 8–10 weeks.
During this period:
- Check periodically to make sure the paper towel remains damp.
- Avoid excess water collecting inside the bag.
- Inspect for mould or early germination.
- If the towel dries, add a small amount of water.
Do Not Skip This Stage
Follow the complete preparation sequence before sowing: soak the seeds, wrap them in a damp paper towel, and refrigerate them for the recommended 8–10 weeks. If a seed begins to sprout during this period, handle it carefully to avoid damaging the emerging root.
04 — PLANT YOUR SEEDS
Plant Your Japanese Maple Seeds
Once the cold-stratification period is complete, your seeds are ready for sowing.
Step 1 — Prepare the Growing Medium
Place the included coco coir growing block in a container and gradually add water until it has fully expanded. Gently loosen the hydrated coir to create an even, loose texture. It should be moist but not waterlogged.
Helpful Tip: For improved aeration and drainage, you can optionally mix a small amount of horticultural perlite into the hydrated coco coir.
Step 2 — Prepare the Pots
Fill a biodegradable peat pot with the prepared growing medium, leaving a little space at the top. Keep the coir loose and avoid compressing it.
Important: Coco coir retains moisture but provides very few nutrients. Do not apply fertilizer during seed preparation or germination. Wait until your seedlings are established and actively growing before introducing suitable plant nutrition.
Step 2 — Sow the Seeds
Place the prepared seeds on the surface of the growing medium and cover them with approximately 5mm of medium. Space the seeds apart where possible to give each seedling room to develop and help reduce competition as they grow.
Avoid sowing seeds too deeply, as excessive depth may limit their exposure to the light needed for successful germination.
Step 3 — Water Thoroughly
Water the pot after sowing. Allow the medium to become thoroughly moist and excess water to drain away.
Keep the growing medium moist, but never leave it waterlogged.
Step 4 — Use Your Transparent Propagation Bag
Place the transparent propagation bag over the pot to help retain humidity.
Make several small air holes in the sides of the bag to allow airflow while retaining humidity.
Monitor the pot carefully. A transparent bag can become hot in direct sunlight, so check the temperature and moisture regularly.
Step 5 — Choose a Suitable Location
Place the pot in a warm, bright location with plenty of light. Aim for 8–12 hours of light daily, using a suitable grow light if needed.
While the transparent propagation bag is covering the pot, avoid strong, direct sunlight, as heat can build up inside and damage the seeds. Check the temperature and moisture regularly, keeping the growing medium moist but not waterlogged.
Maintain a temperature of 20–30°C (68–86°F) during germination. Once the seedlings emerge, they can tolerate slightly cooler temperatures.
05 — GERMINATION
Germination: What to Expect
Japanese Maple germination can take a couple of months or longer. Even when the seeds have been prepared correctly, the timing may vary.
Temperature, light, moisture, growing medium, and seed viability all influence the result. Small differences in growing conditions can make a noticeable difference to germination times.
Avoid disturbing the seeds unnecessarily. Continue checking moisture and maintaining suitable growing conditions while you wait for the first signs of growth.
Patience Is Part of the Journey
Growing bonsai from seed is a gradual process. Germination is not guaranteed, so do not assume a seed has failed simply because it has not sprouted as quickly as expected.
06 — CARING FOR YOUR FIRST SEEDLINGS
Caring for Your First Seedlings
Gradually Remove the Propagation Bag
Once seedlings emerge, increase ventilation by opening the bag more frequently. Remove it progressively as the seedlings become established and adapt to the surrounding humidity.
Provide Suitable Light
Provide suitable light for the seedlings and monitor them carefully, especially in hot weather, to avoid excessive heat stress.
Water Carefully
Keep the growing medium consistently moist, avoiding both waterlogging and excessive dryness. Check it regularly and adjust watering according to how quickly it dries.
Allow the Seedlings to Establish
If several seedlings grow close together, separate them into individual pots once they are strong enough to tolerate transplanting.
Handle roots gently and avoid unnecessary disturbance. At this stage, the priority is healthy root, stem, and foliage development rather than detailed bonsai styling.
07 — FROM SEEDLING TO YOUNG TREE
From Seedling to Young Tree
As your Japanese Maple grows, focus on developing a healthy root system and allowing the tree to establish itself before beginning extensive pruning or wiring.
When Should You Repot?
Assess the plant's health and root development before disturbing it. Established Japanese Maples may need repotting every one to two years, while more mature trees may need it every two to three years, depending on root development and growing conditions.
Repot in spring, ideally alongside root pruning. Although Japanese Maples have relatively shallow root systems, choose a container that provides sufficient space for healthy root growth.
Prepare for Future Training
Allow your young tree to develop before beginning detailed bonsai styling. The timing of pruning and wiring should reflect the tree's strength and stage of development.
Build a Strong Foundation
Healthy roots and steady growth come first. Give your Japanese Maple time to establish itself before attempting more advanced bonsai techniques.
08 — LONG-TERM CARE
Long-Term Care
Watering
Keep the growing medium consistently moist, avoiding both waterlogging and excessive dryness. Mist the foliage regularly to help maintain humidity around the plant.
Use rainwater, filtered water, or bottled water to hydrate your Japanese Maple, particularly if your tap water contains high levels of chlorine or dissolved minerals. Monitor the growing medium and your plant’s response to ensure the water you use is suitable.
Helpful Tip: Before watering, gently check the growing medium with your fingertip to assess its moisture level. Adjust your watering frequency to the growing conditions rather than following a fixed schedule. Keep the medium moist, but avoid waterlogging.
Using Your Included Fertilizer
Your Bonsai Journey™ kit includes Seaweed Extract, FUZICO+, and NPK 20-20-20 for later stages of plant care.
During seed preparation, germination, and early seedling growth, focus on providing suitable moisture, light, and temperature without applying fertilizer. Once your seedling is well established, healthy, and actively growing, gradually introduce plant nutrition, following each product’s recommended dilution and application instructions.
Seasonal Fertilizing
As your Japanese Maple matures, its feeding needs change with the seasons. Follow this seasonal guidance for an established bonsai tree:
-
Early spring: Use a nitrogen-heavy fertilizer weekly while the buds are opening.
-
Hottest periods of summer: Reduce feeding.
-
Late summer: Switch to a nitrogen-free fertilizer.
-
Autumn and winter: Gradually reduce and eventually stop feeding as the tree enters dormancy.
Always follow the selected fertilizer’s label for dosage and application, and adjust feeding to the tree’s condition and growing environment.
Note: Your included NPK 20-20-20+TE contains nitrogen, so it is not a substitute for the nitrogen-free fertilizer recommended for late-summer feeding of established bonsai.
Pruning
Begin pruning in early spring, approximately two weeks before repotting. Pruning branches in midsummer can encourage new shoots to develop from the internodes. Pinch the tips of new shoots when two or four complete leaves have formed. Repeat as needed to maintain the tree’s shape and encourage branching.
Repotting
Repot your Japanese Maple every one to two years, or every two to three years as it matures. Repot in spring, alongside root pruning, and choose a relatively shallow container that provides sufficient space for healthy root growth.
Future Bonsai Development
Japanese Maples can develop beautiful branching and seasonal foliage when grown under suitable conditions.
For guidance on pruning, branch selection, shaping, and the safe use of your bonsai training wire, refer to “When to Begin Bonsai Training” in the main The Bonsai Journey™ Growing Guide.
09 — FREQUENTLY ASKED QUESTIONS
Frequently Asked Questions
Why do Japanese Maple seeds need cold stratification?
Cold stratification helps Japanese Maple seeds overcome dormancy by exposing them to cold, moist conditions before sowing, preparing them for germination.
Can I tell if a seed is viable by floating it in water?
Not reliably. A seed that floats is not necessarily non-viable, so do not discard seeds based on the floating test alone.
How long should I refrigerate the seeds?
Soak the seeds in warm water for 24–48 hours, then keep them in a damp paper towel inside a resealable bag in the refrigerator for 8–10 weeks.
How deep should I plant the seeds?
Cover the seeds with approximately 5mm of growing medium, following the species-specific sowing instructions.
What size pot should I use for my Japanese Maple bonsai?
The right pot size depends on the size of your tree and how you want it to develop. As a general guideline, the length of the pot can be approximately two-thirds of the tree’s height. This is a general bonsai guideline for later development, not a requirement for your initial seed-starting pot.
Do I need specialist bonsai tools?
Specialist bonsai tools are not essential at the beginning, but suitable tools can help you make cleaner cuts and reduce the risk of damaging your tree when pruning and shaping it. Your kit includes bonsai planting tools and training wire for future care.
What should I do if my seeds are not growing?
Be patient, as germination can take a couple of months or longer. Check that you followed the recommended seed preparation, including the 24–48-hour warm-water soak and 8–10 weeks of cold stratification. Also check the growing medium’s moisture, temperature, light, and ventilation. If no seedlings emerge, unsuitable conditions or seed viability may be factors.
Will every seed grow into a tree?
No. Germination and early seedling survival are not guaranteed. Seed viability, preparation, moisture, temperature, and other growing conditions all affect the outcome, and some seedlings may not survive even with appropriate care.
When should I separate the seedlings?
Space seeds apart when sowing, where possible. If multiple seedlings grow close together, separate them into individual pots once they are strong enough to tolerate being moved. Handle the delicate roots carefully to minimise disturbance.
Can I start Japanese Maple seeds indoors at any time of year?
Indoor sowing can be attempted throughout the year when you can control the growing conditions. Suitable light, temperature, and moisture can help support germination, while indoor growing also protects young plants from strong winds and sudden outdoor temperature changes.
How long does it take to grow a mature bonsai?
Growing a mature bonsai from seed is a long-term process that can take many years. The timeline depends on the tree’s growth, growing conditions, and the size and style you want to develop. Focus first on raising a healthy young tree before beginning more advanced bonsai training.
What growing medium is suitable when my tree matures?
The included coco coir is intended for starting your seeds. As your Japanese Maple matures, you can consider a suitable bonsai soil mix for established trees. The growing guide mentions mixes containing lava rock and akadama for future bonsai development.
What temperature is recommended for germination?
Maintain a temperature of 20–30°C (68–86°F) during germination. Once the seedlings emerge, they can thrive at slightly lower temperatures.
How much light do the seeds need?
Aim for 8–12 hours of light daily, using a suitable grow light to supplement natural light when needed. During germination, keep the covered pot in a bright, warm location but away from strong direct sunlight, as heat can build up inside the propagation bag and damage the seeds.
Should I seal the propagation bag completely?
No. Make small air holes in the sides of the propagation bag to allow airflow while retaining humidity around the seeds.
How long will germination take?
Germination can take a couple of months or longer. Timing varies with seed viability and growing conditions.
When should I begin bonsai training?
Focus first on establishing a healthy young tree. Detailed pruning and wiring should wait until the tree is sufficiently established. Refer to the main growing guide for further training advice.
How do I prepare the bonsai coco coir?
Soak the included coco coir growing block in water until fully expanded, then mix thoroughly to ensure the growing medium is evenly moist but not waterlogged. Fill the biodegradable peat pot loosely, without compacting the medium, leaving a small space at the top.
When should I use the fertilizer?
Do not apply fertilizer to newly sown seeds. Wait until seedlings are established and follow the individual product instructions for the correct dilution, timing, and frequency. These fertilizers have different formulations, so do not assume they are used in the same way.
Is germination guaranteed?
No. Germination and early seedling survival depend on seed viability and growing conditions. Even with appropriate preparation, success cannot be guaranteed.
THE BONSAI JOURNEY™
Ready to Begin Your Bonsai Journey?
Start growing your own miniature tree from seed with The Bonsai Journey™ | Premium Bonsai Growing Kit by ROUGE ‘N’ LOVE.
Some things take time. Enjoy each stage as you nurture your Japanese Maple from its earliest beginnings.
Discover The Bonsai Journey™Begin with a seed.
Nurture the growth.
Shape the future.
The Bonsai Journey™
ROUGE ‘N’ LOVE
