It’s a question every bonsai lover encounters sooner or later: glazed or unglazed? Visit almost any bonsai nursery and you’ll find plenty of both. Unglazed pots in natural browns and terracotta tones alongside glazed pots in vibrant blues, greens, whites, and reds. While they serve the same fundamental purpose, they’re far from interchangeable.
Understanding the differences between glazed and unglazed bonsai pots (and knowing which type best suits your tree), is one of the most useful skills a bonsai grower can develop.
What’s the Actual Difference?
The difference is straightforward: glazed bonsai pots have a glass-like coating fused to the clay surface during firing. This coating gives glazed pots their colour, sheen, and smooth finish. Unglazed pots, on the other hand, have no coating, leaving the natural clay surface exposed after firing.
As our Ebook explains: while simple, this distinction has a significant impact on how the pot performs and the types of trees it best complements.
Unglazed Bonsai Pots: The Horticultural Choice
Unglazed bonsai pots have long been the preferred choice for traditional bonsai cultivation, and with good reason.
Breathability: The porous nature of unglazed clay allows air and moisture to move through the pot walls. This helps deliver a steady supply of oxygen to the root system, supporting healthy root development over the long term.
Moisture regulation: Because unglazed pots gradually release moisture through their walls, they help create a more balanced root environment. This natural moisture exchange can reduce the risk of both overwatering and rapid drying.
Temperature moderation: Terracotta and other unglazed clays absorb heat during the day and release it slowly, helping to reduce temperature fluctuations around the root zone. This can be particularly beneficial during warmer months in places like Queensland, Northern Territory and Regional New South Wales & Victoria.
Timeless aesthetics: The natural, earthy tones of unglazed bonsai pots complement rather than compete with the tree. They provide a subtle backdrop that allows features such as trunk movement, mature bark, ramification, and deadwood to take centre stage.
Best suited to: Conifers such as pines, junipers, spruce, and larch, as well as bonsai valued for their aged bark, deadwood features, or strong trunk character. They are also ideal for species that thrive in well-aerated, free-draining soil conditions.
Glazed Bonsai Pots: Colour, Character and Visual Drama
Glazed bonsai pots bring colour, character, and visual interest to a bonsai composition. When paired thoughtfully with the right tree, a glazed pot can enhance the overall display and draw attention to seasonal features such as flowers, fruit, or autumn foliage.
Moisture retention: The glazed surface creates a non-porous barrier, preventing water from escaping through the pot walls. As a result, glazed bonsai pots generally retain moisture for longer than unglazed pots, which can influence watering requirements depending on the species and climate.
A wide range of colours: One of the biggest advantages of glazed bonsai pots is the variety of colours and finishes available. From subtle earth tones to vibrant blues, greens, reds, whites, and purples, glazed pots offer significant creative freedom when matching a pot to a tree’s foliage, flowers, fruit, or seasonal colour changes.
Enhanced presentation: A quality glazed pot can elevate the appearance of a bonsai, adding refinement and visual balance to the overall composition. For display trees, exhibition bonsai, or specimens showcased in prominent locations, the right glazed pot can be a key design element.
Best suited to: Flowering and fruiting bonsai such as azaleas, wisteria, crabapple, and quince, as well as deciduous species known for vibrant autumn colour. Glazed pots are particularly effective where the relationship between the tree’s seasonal characteristics and the pot’s colour plays an important role in the overall design.
The One Rule: Never Glaze the Inside
This point is important enough to emphasise: avoid bonsai pots that are glazed on both the inside and outside surfaces. A fully glazed interior prevents any moisture exchange through the clay, reducing a key advantage of traditional bonsai containers. The exterior glaze is purely decorative, while the interior should remain unglazed to support a healthier root environment and better moisture management.
When buying a glazed bonsai pot, always check the inside as well as the outside. Quality bonsai pots are typically glazed externally for appearance, while the interior surface is left unglazed.
Colour Matching: The Glazed Pot Guide
Choosing the colour of a glazed pot requires thinking beyond the tree’s current appearance. Consider the full seasonal cycle: spring growth, summer fullness, autumn colour where relevant, and winter silhouette.
For trees with red flowers or foliage: light or dark blue, or light or dark green. These complementary tones create visual contrast without conflict.
For trees with pink flowers: blue, green or white. Cool, clean tones that frame pink beautifully without overpowering it.
For trees with orange tones: brown or green. Warm, grounding tones that support rather than clash with orange.
For trees with yellow foliage or flowers: dark green, dark blue or cream. Rich, anchoring tones that balance the brightness of yellow.
For deciduous trees in general: soft greys and muted tones. These work across all four seasons, from spring green through to bare winter branches.
For conifers: skip the glazed pot entirely. Unglazed brown, grey or black is always the right choice for pines and similar species.
What About Plastic Training Pots?
Before a tree reaches its final display pot, glazed or unglazed, many growers use plastic training pots for the development phase. These have several practical advantages: they’re inexpensive, lightweight, available in large sizes, and durable enough to handle regular repotting. Their breathability is lower than terracotta, but at the development stage this is generally less important than cost and practicality.
Once your tree has reached its intended shape and size, it’s time to move it into its final pot. Think of the training pot as scaffolding: useful during construction, not part of the finished building.
A Simple Decision Guide
Not sure which to choose? Run through these questions:
Is your tree a conifer or juniper? → Unglazed. Always.
Does your tree flower or fruit? → Consider a glazed pot in a complementary colour.
Is moisture retention a concern in your climate? → Lean toward unglazed for better moisture management.
Is this a display tree you want to showcase? → A quality glazed pot adds exhibition-level presentation.
Is the tree still in development? → Use a plastic training pot until the final form is established.
Glazed and unglazed bonsai pots each have their place. The best bonsai collections include both: each tree matched to the pot that best serves its character, its health, and the vision you have for it as a composition.
Browse our full range of glazed, unglazed, cascade, shohin and training pots: Australia’s largest online selection with fast nationwide shipping and breakage replacement guarantee.
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