Pruning Japanese Maples (Bonsai Too!): The Complete Guide

Pruning Japanese Maples (Bonsai Too!): The Complete Guide

Japanese maples (Acer palmatum) have long been a highly desirable addition to gardens and landscapes for their bold colors and delicate leaves. Pruning your Japanese maple every year is essential to maintaining healthy growth and achieving the shape you want. In this article, we’ll cover everything you need to know about pruning Japanese maples including: the best time to prune, how to create a bonsai Japanese maple, what pruning techniques work best, and how to care for your Japanese maple after pruning.

(Featured Image: Japanese Maple Fall Foliage by B. Hancock)

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When Is The Best Time To Prune A Japanese Maple?

The best time to prune a Japanese maple tree is during the dormant season, which typically falls in late winter to early spring. Pruning during this period has several advantages. First, without leaves on the tree, you have a clear view of its structure, making it easier to assess and make precise pruning cuts.

Second, pruning during dormancy places less stress on the tree since its energy is concentrated in the roots and trunk, reducing the potential harm to the overall health of the tree.

Additionally, many pests and diseases that affect Japanese maples are less active or dormant during the winter, minimizing the risk of infestation or disease transmission through pruning cuts. Finally, pruning just before the growing season encourages the tree to produce new growth in the spring, aiding in shaping and rejuvenating the tree.

It’s important to note that while late winter to early spring is generally the best time for major pruning, you can also perform light pruning during the summer months if needed. However, be cautious not to over-prune during this period, as it may lead to reduced growth or stress on the tree.

What Are The Best Tools To Use When Pruning Japanese Maples?

Pruning Japanese maple trees effectively requires the right tools to make clean cuts without damaging the tree. Here are the best tools to use for pruning Japanese maples:

  1. Pruning Shears (Hand Pruners):
    • Ideal for cutting small branches, twigs, and foliage up to 1/2 inch in diameter.
    • Choose high-quality hand pruners with sharp blades for clean cuts.
    • Look for models with ergonomic handles for comfort during extended use.
  2. Loppers:
    • Loppers are suitable for cutting larger branches, typically those between 1/2 inch and 1.5 inches in diameter.
    • They offer more leverage and reach than hand pruners.
    • Invest in loppers with extendable handles for more leverage on larger branches.
  3. Pruning Saw:
    • Pruning saws are essential for removing larger branches and limbs, usually over 1.5 inches in diameter.
    • Choose a pruning saw with a sharp, curved blade designed for efficient cutting in tight spaces.
  4. Pole Pruners or Pole Saws:
    • These tools are useful for reaching high branches without the need for a ladder.
    • Pole pruners typically have a pruning shear or saw blade at the end of an extendable pole.
    • Ensure that the pole pruner you choose is sturdy, adjustable, and easy to control.
  5. Hedge Shears (for fine shaping):
    • If you need to perform fine shaping and detailing, hedge shears with sharp blades can be handy.
    • Use them sparingly for precise shaping and grooming of your Japanese maple.
    • We love the Ryobi Hedge Sweep battery operated hedge trimmers for pruning more intricate plants like Japanese maples. It is lightweight and easy to handle.

How To Prune A Japanese Maple Tree

  1. Selectively Prune:
    • Japanese maples have unique and delicate growth patterns, so it’s essential to selectively prune. This means choosing which branches to trim based on their health, position, and aesthetic impact.
    • Avoid heavy or aggressive pruning that could disrupt the tree’s natural form.
  2. Start with Dead or Diseased Branches:
    • Dead, damaged, or diseased branches should be the first to go. Pruning these branches promotes the overall health of the tree and prevents potential issues from spreading.
    • Fungal diseases can be common in Japanese maples that are grown in wet climates. Pruning off any affected leaves can prevent fungal infections from spreading to the rest of the tree.
  3. Thin The Canopy:
    • Thinning the canopy involves selectively removing branches to create more space between them. This opens up the tree, improving air circulation and allowing more light to reach the inner branches.
    • Thin out any overcrowded, crossing, or weak branches. Proper thinning helps reduce the risk of diseases like powdery mildew and promotes better growth.
  4. Prune For Aesthetics:
    • When pruning for aesthetics, focus on enhancing the tree’s natural shape and beauty rather than trying to force it into a specific form.
    • Japanese maples have a wide variety of growth habits, so you can prune to accentuate their unique characteristics.
  5. Size Control:
    • If your Japanese maple is growing too large for its space, you can reduce its size through selective branch removal. However, be cautious not to remove more than one-third of the tree’s foliage in one pruning session.
    • Gradual size reduction over several seasons is often better than drastic pruning.
  6. Avoid Over-Pruning:
    • Over-pruning, especially in a single session, can stress the tree and lead to poor growth or dieback.
    • Light, regular pruning is usually more effective and less stressful for the tree than infrequent, heavy pruning.
  7. Proper Cuts:
    • Make clean, precise cuts just outside the branch collar, which is the swollen area where a branch attaches to the trunk or another branch. Avoid leaving stubs, as they can invite disease and decay.
    • Cutting at a slight angle helps water run off and reduces the risk of moisture accumulating on the cut surface.
  8. Seasonal Pruning:
    • Major pruning is best done during the dormant season (late winter to early spring) when the tree is not actively growing. This minimizes stress and bleeding from cut branches.
    • Light pruning for shaping or maintenance can be done in late summer to early fall.
  9. Regular Maintenance:
    • Incorporate pruning as part of your regular maintenance routine to keep the tree’s shape and size in check.
    • Light, frequent pruning is less likely to stress the tree than occasional, heavy pruning.
  10. Disease and Pest Inspection:
    • While pruning, inspect the tree for signs of diseases or pests. If you notice any issues, address them promptly by removing affected branches or implementing appropriate treatments.

Pruning Japanese maples is a skill that improves with experience. It’s essential to maintain the tree’s health while achieving your desired aesthetic goals. If you’re unsure about how to prune your specific Japanese maple variety, seek guidance from a local arborist or horticulturist who can provide personalized advice based on your tree’s needs and growth habits.

A pruned Japanese Maple tree in stone based landscaping.

Pruned Japanese Maple

Tips For A Healthy Pruning Process

Pruning is an essential horticultural practice that can promote plant health, shape, and overall vitality when done correctly. Here are some tips for proper pruning:

  1. Use Sharp, Clean Tools:
    • Sharp pruning tools make cleaner cuts, reducing the risk of tearing or damaging the plant tissue. Regularly sharpen your pruning shears, loppers, and saws.
    • Keep your tools clean and sterilized between cuts to prevent the spread of diseases between plants. A solution of 70% rubbing alcohol or a 10% bleach solution works well for sterilization.
  2. Choose the Right Tool for the Job:
    • Use the appropriate tool for the size and type of branch you’re pruning. Hand pruners are ideal for smaller branches, while loppers or saws are better for larger ones.
    • Specialized tools like pruning saws and concave branch cutters can be useful for specific pruning tasks.
  3. Prune at the Right Time:
    • Prune at the appropriate time for the plant species. Some plants are best pruned during their dormant season, while others benefit from pruning after flowering or during the growing season.
    • For most deciduous trees and shrubs, late winter to early spring (dormant season) is a good time for major pruning.
  4. Understand Pruning Objectives:
    • Clearly define your pruning goals before you start. Are you pruning for size control, shape, or to remove dead or diseased branches?
    • Understanding your objectives will help you make informed decisions about which branches to prune and how much to remove.
  5. Make Proper Cuts:
    • Always make clean cuts just outside the branch collar (the swollen area where the branch meets the trunk or another branch). Avoid leaving stubs or cutting too close to the trunk.
    • Cut at a slight angle to encourage water runoff and prevent moisture from sitting on the cut surface.
  6. Prune Conservatively:
    • Avoid over-pruning. Removing too much foliage at once can stress the plant and inhibit its ability to photosynthesize.
    • The general rule is not to remove more than one-third of a plant’s foliage in a single pruning session.
  7. Pay Attention to Branch Angles:
    • When making cuts to remove branches, pay attention to the angle at which they attach to the trunk. Proper branch angles promote structural stability and reduce the risk of branch failure.
  8. Consider the Plant’s Growth Habit:
    • Different plants have different growth habits. Be mindful of the natural growth pattern of the plant when pruning. Some plants are best pruned to accentuate their natural shape.
  9. Clean Up and Dispose of Debris:
    • After pruning, remove and dispose of the cut branches and debris properly. This helps prevent disease and pest issues and keeps your garden tidy.
  10. Inspect for Diseases and Pests:
    • While pruning, take the opportunity to inspect the plant for signs of diseases or pests. If you notice any issues, take appropriate action, such as removing affected branches or treating the plant.
  11. Regular Maintenance:
    • Incorporate regular pruning as part of your overall garden maintenance. Consistent, light pruning is often more effective and less stressful for plants than sporadic, heavy pruning.
  12. Educate Yourself:
    • Learn about the specific needs and preferences of the plants in your garden. Different species may require different pruning techniques and timing.

Remember that pruning is both a science and an art. It’s essential to balance your objectives with the needs of the plant to maintain its health and beauty. If you’re unsure about how to prune a particular plant or tree, seek guidance from gardening books, online resources, or local horticultural experts.

What Varieties Of Japanese Maple Are Best For Bonsai?

Several varieties of Japanese maples are well-suited for bonsai cultivation due to their compact size, attractive foliage, and adaptability to bonsai techniques. Here are some of the best Japanese maple varieties for bonsai:

  • Size: Bloodgood is a medium-sized Japanese maple, typically reaching a height of 6-10 ft that is easily maintained as a bonsai tree.
  • Characteristics: This cultivar is prized for its deep red to burgundy foliage, which remains vibrant throughout the growing season. The leaves are palmate, and their color intensifies in the fall. Bloodgood has an upright growth habit and a classic, elegant appearance. It’s a favorite for its stunning color and versatility in various garden settings.
  • Click here to view more photos and purchasing options for Bloodgood Japanese Maples.
Bloodgood Japanese maple trees are bright red and make a great option for bonsai Japanese Maples.
  • Size: Red Dragon is a compact, slow-growing Japanese maple, typically reaching a height of 6 to 8 feet that is significantly shorter when pruned.
  • Characteristics: This cultivar is renowned for its deeply dissected, crimson-red foliage. The leaves maintain their rich red color throughout the growing season, making it a standout in any garden. In the fall, the leaves may turn shades of scarlet and orange. Red Dragon has a cascading growth habit, making it an excellent choice for containers, where its graceful branches can spill over the edges.
  • Click here to view more photos and purchasing options for Red Dragon Japanese Maples.
  • Size: Crimson Queen is a dwarf Japanese maple, typically staying under 6″ tall without pruning.
  • Characteristics: This cultivar is prized for its finely dissected, lacy, deep red foliage, which maintains its color throughout the growing season. In the autumn, the leaves often intensify to a brilliant scarlet. Crimson Queen has a cascading and mounding growth habit, creating a picturesque, weeping appearance. It’s an excellent choice for containers, rock gardens, or as a focal point in smaller spaces.
  • Click here to view purchasing options and more photos of Crimson Queen Japanese Maples.
The Crimson Queen Japanese maple is easily pruned into a bonsai shape.
  • Size: Waterfall is a dwarf Japanese maple, typically staying under 6 feet in height without pruning.
  • Characteristics: Waterfall is a stunning weeping or cascading cultivar with finely dissected, lace-like green foliage. Its elegant, pendulous branches create a waterfall-like effect. In the fall, the leaves often turn to vibrant shades of yellow, orange, or red, adding a pop of color to your garden or container display. Its small size and unique form make it an excellent choice for smaller spaces or containers.
  • To view more photos and purchasing options for Waterfall Japanese Maples, click here!
With a small shape and bonsai features, the Waterfall Japanese maple can be a bonsai tree.

What Tools Are Best For Shaping A Japanese Maple Bonsai?

Shaping a bonsai Japanese maple requires precision and careful attention to detail. To achieve the desired shape and maintain the health of the bonsai tree, you’ll need the following tools:

  1. Bonsai Pruning Shears (Scissors):
    • Bonsai pruning shears are essential for precision pruning and maintaining the tree’s size and shape.
    • They come in various shapes and sizes, including straight, curved, and long-handled versions, to handle different types of cuts.
  2. Concave Branch Cutters:
    • These specialized bonsai tools have a concave cutting edge that allows you to make clean cuts while minimizing scarring.
    • Use concave branch cutters for removing larger branches and stubs while promoting quicker healing of the wounds.
  3. Wire Cutters:
    • Bonsai wire cutters are used to remove or adjust wires that are used to shape the branches of the bonsai.
    • They have flat jaws designed to cut wire cleanly without damaging the tree.
  4. Bonsai Knob Cutters (optional):
    • Bonsai knob cutters are handy for creating concave cuts when removing larger branches or for deadwood work.
    • While not essential for all pruning tasks, they can be helpful for specific shaping techniques.
  5. Root Pruning Tools (optional):
    • Root pruning is also a crucial part of bonsai care. Root pruners or root scissors are used for trimming and maintaining the root system.
    • These tools help control the size and shape of the root ball.
  6. Tweezers and Chopsticks (for fine work):
    • Tweezers and chopsticks can be used for delicate manipulation of foliage, fine branches, and small details when shaping your bonsai.
  7. Wire for Training:
    • Bonsai shaping often involves wiring branches to achieve the desired position and shape. Use specialized bonsai wire of the appropriate thickness for your tree.
  8. Wire Cutters (for wire removal):
    • These wire cutters are used to safely remove wires from the tree without damaging the branches.
  9. Pruning Paste or Sealant:
    • After making cuts, you can apply pruning paste or sealant to protect the wounds and promote healing.

How To Prune A Japanese Maple Bonsai

Step 1: Assess the Bonsai:

  • Examine your Japanese maple bonsai to identify areas that need pruning. Look for branches that are overgrown, crossing, or growing in undesirable directions.

Step 2: Identify Your Pruning Goals:

  • Determine your pruning objectives. Are you aiming to refine the shape, reduce size, or simply maintain the existing form of the bonsai?

Step 3: Prune Dead or Diseased Branches:

  • Start by removing any dead, diseased, or damaged branches. This step is crucial for the health of the bonsai.

Step 4: Thin Out the Canopy:

  • Thin out the canopy by selectively removing branches that are too dense or overcrowded. This improves air circulation and allows light to reach inner branches.

Step 5: Selective Pruning:

  • Carefully choose which branches to prune, keeping in mind the overall design and balance of the bonsai.
  • Prune branches that disrupt the desired shape or growth pattern, but avoid over-pruning or removing too much foliage at once.

Step 6: Create Taper and Balance:

  • Japanese maple bonsai often have a tapered appearance, with thinner branches towards the top. Prune accordingly to maintain this taper.
  • Balance the bonsai by pruning branches on one side if necessary, to ensure a harmonious appearance.

Step 7: Use Pruning Shears for Small Cuts:

  • For small cuts, use bonsai pruning shears to make clean, precise cuts just outside the branch collar. Avoid leaving stubs or causing unnecessary damage.

Step 8: Use Concave Branch Cutters for Larger Cuts:

  • For larger branches, use concave branch cutters. These tools create concave cuts that heal more effectively and look more natural.
  • Make a clean, angled cut, and then smooth the cut surface.

Step 9: Wiring (if needed):

  • If you wish to reshape or position branches, use bonsai wire. Gently wrap the wire around the branch, being careful not to damage the bark, and shape the branch as desired.
  • Monitor the wire to prevent it from cutting into the bark; remove it once the branch sets in the desired position.

Step 10: Apply Pruning Paste (optional):– If you make larger cuts, consider applying pruning paste or sealant to protect the wounds and aid in healing. This is especially useful for cuts that may take longer to close.

Step 11: Regular Maintenance:– Pruning is an ongoing process for bonsai care. Regularly inspect and maintain the bonsai’s shape and health to keep it looking its best.

Remember that pruning is a balance between shaping your bonsai and maintaining its health. Take your time, make thoughtful cuts, and periodically step back to assess the overall design as you work. Additionally, Japanese maple bonsai may have specific care requirements depending on the variety, so be sure to research the particular needs of your bonsai to ensure its long-term health and vitality.

How To Train A Japanese Maple Bonsai Tree

Training a Japanese maple bonsai involves shaping its branches, trunk, and overall form to create an aesthetically pleasing miniature tree. Here’s a step-by-step guide on how to train a Japanese maple bonsai:

Tools You’ll Need:

  • Bonsai wire (copper or aluminum)
  • Wire cutters
  • Pruning shears
  • Concave cutters (for larger cuts)
  • Raffia (optional, for protecting branches during bending)
  • Guy wires (optional, for branch bending)
  • Bonsai training pots or containers

Step 1: Choose the Right Bonsai Material:

  • Start with a young plant or Japanese maple nursery stock with a desirable trunk and root structure. The ideal bonsai candidate should have an interesting trunk shape and well-distributed branch structure.

Step 2: Understand Your Design Goals:

  • Determine the style and design you want for your Japanese maple bonsai. Common styles include formal upright, informal upright, cascade, and broom, among others. Your choice will guide your training efforts.

Step 3: Structural Pruning:

  • Begin by pruning away any unwanted branches, especially those that grow directly from the trunk, leaving only the branches you intend to develop as primary branches and the apex (top of the tree).

Step 4: Wiring for Shape:

  • Use bonsai wire to gently bend and shape the branches into the desired position. Copper or aluminum wire is commonly used for this purpose.
  • Start by wiring the lower branches first, working your way up the tree. Anchor the wire near the base of the branch and wrap it around the branch at an angle.
  • Be careful not to overtighten the wire, as it can cut into the bark. Use raffia or soft materials to protect the branch if necessary.
  • Position branches to create the desired structure and silhouette for your bonsai style.

Step 5: Trunk Movement (Optional):

  • If you want to create movement in the trunk, you can use guy wires in addition to wiring. Attach guy wires to branches or trunk sections and gently pull or push to achieve the desired curve or bend.
  • Monitor the tree’s response to bending, and adjust as needed. Bending should be gradual and should not damage the tree.

Step 6: Prune for Fine Detail:

  • Continuously prune and refine the branches to create taper and balance in the bonsai’s design. Remove any unwanted growth, especially buds that may emerge in undesirable locations.
  • As the tree grows, keep refining its shape to maintain the desired style.

Step 7: Repotting and Root Pruning:

  • Repot your Japanese maple bonsai every 2-3 years to refresh the soil and encourage healthy root growth.
  • During repotting, consider root pruning to maintain a compact root system suitable for the size of your bonsai pot.

Step 8: Patience and Ongoing Care:

  • Bonsai training is a long-term process that requires patience and regular attention. Continue to monitor and adjust the wiring and pruning as your bonsai grows.
  • Protect your bonsai from extreme weather conditions, pests, and diseases.

Step 9: Display and Enjoy:

  • Once your Japanese maple bonsai has reached the desired form and size, display it in a suitable bonsai pot, and enjoy the beauty of your miniature tree.

Remember that the art of Bonsai requires patience, and the tree will evolve over time. Continuously study and refine your techniques, and don’t be afraid to seek guidance from experienced bonsai enthusiasts or professionals. With dedication and proper care, you can create a stunning Japanese maple bonsai that showcases the beauty of this beloved tree species.

How To Care For A Japanese Maple After Pruning

Proper care after pruning is essential to the health of Japanese maples, especially when pruning young trees.  Water the tree thoroughly after pruning to help it recover and reduce stress. Adequate moisture is crucial during the healing process. Ensure the soil is consistently moist, but not waterlogged, especially in the weeks following pruning.

It is a good idea to mulch the base of the tree with a layer of organic mulch, such as wood chips or compost, helps retain soil moisture and regulates temperature. Additionally, mulch suppresses weeds and adds nutrients to the soil as it breaks down.

Monitor the tree for any signs of stress or disease in the weeks and months following pruning. Keep an eye out for wilting leaves, abnormal discoloration, or unusual growth patterns. If you notice any issues, address them promptly with appropriate treatments or adjustments. Regularly inspect the tree’s branches to ensure that wires, if used for shaping, are not cutting into the bark as the tree grows. Continue to provide routine maintenance, including periodic pruning to maintain the desired shape and structure.

Finally, be patient, as Japanese maples can take some time to fully recover from pruning, and their beauty and health will gradually return as they grow and adapt to their new form.

Everything You Need To Know About Japanese Maples

Looking to add more Japanese maples to your yard? These beautiful trees are a good choice for landscapes in the midwest and many regions across North America. Add unique forms to an existing bonsai collection, or just add them for their beautiful fall foliage. Whatever the reason, Japanese maples are easy to care for and fun to prune!

To learn more about growing Japanese Maple Trees in your yard, check out these growing guides!

A mature Japanese Maple Tree after years of shaping and pruning.