Introduction

Kashima is a dwarf Japanese maple cultivar prized for its very small leaves, extremely short internodes, and compact upright growth habit that makes it one of the finest choices for shohin and mame bonsai. Unlike the spreading Kiyohime, Kashima grows more upright and develops tighter, more angular branching. Leaves are among the smallest in the palmatum cultivar group, reaching only 2-3 cm across at maturity, and autumn colour is a soft yellow to light orange.

Leaves are five-lobed, delicate, and remarkably small — 2-3 cm across on well-managed bonsai. Spring foliage emerges light green with subtle pinkish edges. Summer colour is fresh green. Autumn colour ranges from clear yellow to soft orange, less intense than Deshojo but elegant. Internodes average 3-6 mm — among the shortest of any palmatum cultivar. The growth habit is more upright than Kiyohime, forming an oval to vase-shaped canopy rather than a flat dome.

History & Tradition

Kashima entered the bonsai world as part of the Japanese shohin movement that gained momentum in the 1970s-80s. The cultivar became available in the West through Japanese nursery exports in the 1990s. It quickly became a staple of shohin exhibitions where the convincing scale of tiny leaves on small trees is a judging criterion. Today it is among the most sought-after cultivars for serious shohin practitioners worldwide.

About Maple Bonsai

Japanese maples are among the most popular deciduous bonsai, prized for their spectacular seasonal color changes and delicate leaf structure. From the fresh chartreuse of spring emergence through deep summer green to the fiery reds and golds of autumn, maples offer a living calendar. Leaf reduction through defoliation techniques can produce miniature leaves barely a centimeter across on well-developed trees. The fine ramification achievable on mature maple bonsai creates winter silhouettes rivaling the best deciduous trees in nature. Acer palmatum cultivars number in the hundreds, giving artists choices ranging from threadleaf dissectums to bold-lobed varieties. Maples prefer morning sun with afternoon shade protection and consistent moisture.

Botanical Profile

Kashima is a dwarf cultivar of A. palmatum selected for its minute foliage and compact growth. The name refers to the Kashima region in Japan. Like Kiyohime, it maintains its dwarf characteristics through vegetative propagation. The extremely short internodes result from compressed cell elongation in the shoot tips. Cold hardiness is comparable to species type, USDA zones 5-8.

Bonsai Styles

Informal upright is the primary style — the natural upright tendency and fine ramification create elegant small trees. Broom style is achievable but less natural than with Kiyohime. Twin-trunk compositions work beautifully at shohin scale. Group plantings of Kashima create exquisite miniature forests with convincing scale. Avoid literati and cascade — the cultivar's strengths lie in classical broadleaf forms.

Group Style Guide

Informal upright (moyogi) is the dominant style for Japanese maples, showcasing their natural graceful form. Broom style (hokidachi) is classical for maples, creating a rounded canopy on a straight trunk that displays autumn color spectacularly. Root over rock (sekijoju) exploits the maple's ability to develop dramatic surface roots gripping stone. Twin trunk (sokan) and clump (kabudachi) styles emphasize the forest-like quality of maple groves. Forest plantings (yose-ue) of maples are among the most popular group compositions. Cascade styles are rare for maples, as the species naturally grows upright.

Trunk & Nebari

Surface roots develop well with careful radial pruning at each repotting. The slow growth limits trunk caliper increase to 2-4 mm per year even in optimal conditions. Trunk-chop technique works but requires extreme patience with 4-5 year cycles between chops. Air-layering above poor nebari is effective but slow — 5-6 months for root development. The thin, smooth bark adds a refined aesthetic that complements the tiny foliage perfectly.

Deadwood Techniques

Deadwood features are inappropriate for Kashima — the tiny branches rot quickly and the aesthetic is entirely about refined living structure. Any dead stubs should be carved concave for bark rollover. The design focus is wholly on canopy refinement, leaf size, and branch ramification.

Wiring & Shaping

Use the finest aluminium wire available (0.5-1.5 mm) for Kashima's delicate branches. Wire in winter after leaf drop. The extremely short internodes make clip-and-grow the primary shaping technique — two or three cuts per season create the desired silhouette. Remove wire within 3 months as the thin bark marks permanently. Handle branches carefully; they are more brittle than species type.

Pruning & Pinching

Cut extending shoots back to 1-2 nodes throughout the growing season. Defoliation is unnecessary and inadvisable — the leaves are already miniature and the dwarf vigour cannot support aggressive defoliation. Selective removal of the largest leaves is acceptable to balance the canopy. Prune opposite buds to singles at every opportunity, choosing the more outward-facing bud. Thin interior density in autumn to maintain light penetration to inner buds.

Watering

Water carefully — the small leaf mass transpires less than vigorous cultivars, so overwatering is a greater risk than with species palmatum. Allow the surface to approach dryness between waterings, but never let the root ball dry completely. In summer, once daily is usually sufficient. The small pot sizes used for shohin Kashima dry out rapidly in wind — protect from desiccating winds.

Soil & Repotting

Standard maple mix sieved to 1-3 mm for shohin and mame work. Repot every 2-3 years in late February to early March. The fine root system fills small pots quickly despite the slow top growth. Root pruning tolerance is moderate — remove no more than 30% of root mass to avoid stressing the dwarf cultivar. Use the shallowest pot proportional to the tree for best aesthetics.

Group Soil Recipes

Deciduous maple substrate should retain more moisture than conifer mixes: 60% akadama, 20% pumice, 20% lava rock or perlite. The higher akadama ratio supports the moisture needs of large-leafed deciduous trees. Particle size of 2–5 mm works well for most sizes. Repot every 2–3 years in early spring before bud break. Root pruning can be aggressive on healthy maples, removing up to 50% of the root mass. A thin layer of sphagnum moss on the soil surface helps maintain even moisture during hot summers.

Fertilizing

Very light feeding — half-strength organic fertilizer every 6-8 weeks from April through August. Excessive feeding pushes uncharacteristically long internodes that ruin the miniature proportions. Low-nitrogen autumn feed supports colour development. If internodes remain consistently short and the tree shows good colour, the feeding level is correct. Kashima is one cultivar where less fertilizer produces a better result than more.

Light & Placement

Morning sun with light afternoon shade produces compact growth and protects the delicate small leaves from scorch. The thin leaves burn more readily than larger, thicker species-type foliage. Full sun in spring and autumn is beneficial. Avoid deep shade, which causes internode stretching even in this naturally short-noded cultivar. Winter sun exposure on the dormant tree is harmless.

Seasonal Placement Guide

Spring: Watch for bud break; protect emerging leaves from late frost; apply dilute fertilizer after leaves harden off. Summer: Partial defoliation in early summer for leaf reduction on strong trees; protect from scorching afternoon sun; maintain consistent moisture. Autumn: Enjoy the color display; reduce fertilizer; leaves drop naturally — remove fallen leaves from soil surface. Winter: Protect roots from hard freezes below -5°C; prune heavy branches during dormancy when sap is down; seal large cuts with wound paste.

Seasonal Care

Spring: Repot if due, enjoy the delicate leaf emergence with pinkish edges. Summer: Light pinching, consistent but moderate watering, afternoon shade protection. Autumn: Thin interior, enjoy yellow-orange colour. Winter: Protect below -10 C, fine wiring work on the visible branch structure. Kashima needs less active management than vigorous cultivars — the compact growth is largely self-regulating.

Group Seasonal Guide

Spring: Watch for bud break; protect emerging leaves from late frost; apply dilute fertilizer after leaves harden off. Summer: Partial defoliation in early summer for leaf reduction on strong trees; protect from scorching afternoon sun; maintain consistent moisture. Autumn: Enjoy the color display; reduce fertilizer; leaves drop naturally — remove fallen leaves from soil surface. Winter: Protect roots from hard freezes below -5°C; prune heavy branches during dormancy when sap is down; seal large cuts with wound paste.

Pests & Diseases

Aphids target the small, tender growth points — inspect regularly and treat early. The dense branching can harbour scale insects on inner stems. Powdery mildew risk is moderate in humid conditions. Verticillium wilt is the serious threat as with all palmatum cultivars. The small size of most Kashima bonsai means a single aphid infestation can damage a significant proportion of the canopy.

Group Pest Guide

Aphids frequently colonize new growth in spring, causing leaf curl and sooty mold; treat with insecticidal soap or systemic insecticide. Powdery mildew appears as white patches on leaves in humid conditions; improve air circulation. Verticillium wilt is a serious fungal disease causing branch dieback; no cure exists, but affected branches can be removed. Scale insects occasionally appear on branches; treat with horticultural oil. Leaf scorch from hot sun or wind is cosmetic but stressful; provide afternoon shade protection.

Propagation

Grafting onto palmatum seedling rootstock is standard. Air-layering is reliable but slow — 5-6 months for adequate root development. Cuttings are difficult with low success rates (under 15%). Seeds do not come true. Own-root specimens from air layers are ideal for bonsai but require patience in establishment. The grafted rootstock provides vigour that the scion cultivar lacks.

Group Propagation Guide

Japanese maples propagate readily from seed collected in autumn. Fresh seed requires 90–120 days cold stratification. Named cultivars must be propagated by grafting or air layering, as seedlings vary. Air layering in spring produces rooted sections within one growing season. Softwood cuttings taken in early summer can root under mist propagation. Approach grafting in spring is used for specialized cultivars. Ground layering of low branches produces new plants while maintaining the mother tree. Seedlings take 3–5 years to reach initial training size.

Size Classification

Premier cultivar for mame (under 15 cm) and shohin (15-25 cm) bonsai. The naturally tiny leaves and microscopic internodes create convincing miniature trees at the smallest bonsai scales. Chuhin is possible but the slow growth makes developing trees above 40 cm impractical. Expect 5-8 years from air layer to display-quality shohin. Kashima is essentially purpose-built for small bonsai.

Varieties & Cultivars

Kiyohime is the closest comparison — similar dwarf character but more spreading habit and slightly larger leaves. Kotohime has even smaller leaves but is more challenging to grow. Shishigashira has short internodes but completely different crinkled leaf character. Seigen offers similar small leaves with the bonus of red spring colour. For smallest-possible bonsai, Kashima and Kotohime are the top two palmatum cultivars.

Group Varieties

Acer palmatum is the primary bonsai maple with hundreds of cultivars. Deshojo has brilliant red spring growth. Kiyohime is naturally compact with fine ramification. Seigen offers red spring and autumn color. Acer buergerianum (trident maple) has superior trunk development and tolerates more sun. Acer ginnala (Amur maple) is extremely cold-hardy. Mountain maple (A. campestre) suits European collections. Dissectum cultivars with thread-like leaves create weeping bonsai forms. Coral bark maple (Sango-kaku) offers year-round red branch color.

Buying Guide & Display

Verify true Kashima by examining internode length and leaf size on mature growth — impostors have longer internodes. Check graft unions carefully on small trees where a bulge is visually disruptive. Air-layered own-root material is significantly superior for bonsai but commands premium prices. Expect $40-80 for small grafted nursery stock, $150-600 for developed bonsai.

Troubleshooting

Elongated internodes mean too much fertilizer or too little light — reduce feeding and increase sun exposure immediately. Die-back of fine branches usually indicates the canopy is too dense and interior light is insufficient — thin aggressively. Slow or absent spring bud break after winter suggests the tree was too dry during dormancy — maintain winter moisture levels carefully. Root-bound symptoms appear sooner than expected because the fine root system fills small pots rapidly.

Common Problems

Display & Exhibition

Tiny glazed pots in light colours — cream, celadon, or pale blue — suit the delicate character. For mame, hand-made accent pots add personality. Display at or slightly below eye level on a small stand. The gentle autumn yellow-orange is best displayed against a neutral background. Accent plantings should be proportionally tiny — a single small grass clump or moss mound.

Group Display Guide

Autumn is the prime season for maple bonsai display, when foliage color creates maximum visual impact. A light-colored oval or rectangular pot in unglazed or subtle grey-blue glaze complements autumn colors. The display stand can be lighter in style than conifer stands, reflecting the tree's delicate character. Spring display showcases fresh green leaves; winter display reveals the branch structure and ramification. A water stone or autumn-themed scroll enhances the seasonal composition. Avoid display in direct sunlight, which fades autumn colors prematurely.