Aconitifolium (Acer japonicum ‘Aconitifolium’)

Acer japonicum 'Aconitifolium' is commonly called fernleaf full moon maple, fernleaf maple, or fern-leaved fullmoon maple. It is a small deciduous maple valued for deeply divided foliage and vivid fall color.

Acer japonicum 'Aconitifolium' typically grows about 8–10 feet tall and wide in cultivation, although size varies with climate and growing conditions. Some specimens may become larger over time.

Yes, it is a full moon maple in the Japanese maple group, but it is Acer japonicum rather than the more commonly grown Acer palmatum. Its leaves are usually larger and more deeply divided than those of many Japanese maple cultivars.

Acer japonicum 'Aconitifolium' is generally suitable for USDA Hardiness Zones 5–7. It is notably cold hardy, but late spring frosts can still damage newly emerging leaves.

Acer japonicum 'Aconitifolium' grows best in partial shade or filtered sun, especially where summers are hot. It can tolerate more sun in cooler climates if the soil stays evenly moist and the site is protected from harsh afternoon heat.

Plant it in a sheltered location with morning sun or filtered light, protection from strong winds, and moist, well-drained soil. An understory position or woodland-edge setting is often ideal.

It can grow in regions with warm summers, but hot, dry conditions increase the risk of leaf scorch. Provide afternoon shade, mulch the root zone, and water consistently during summer drought.

Allow roughly 8–12 feet of open space for a typical mature plant, with additional room if a larger specimen is expected. Keep it away from structures, utility lines, and locations where compacted soil or reflected heat is common.

It can be grown in a large container while young, provided the pot has excellent drainage and the root zone does not dry out. Container plants require more frequent watering and may need extra winter protection than plants in the ground.

Water deeply whenever the soil begins to dry slightly below the surface, keeping moisture even but not waterlogged. Newly planted trees need regular irrigation during their first growing season and during extended summer drought.

The best soil is moist, fertile, well-drained loam with good organic matter. Avoid heavy, poorly drained soil and very dry, sandy sites unless irrigation and organic amendments can maintain consistent moisture.

Brown leaf edges or patches are most often caused by heat, drought, wind, or sudden exposure to strong sun. Keep the soil evenly moist, add a 2–3 inch mulch layer without touching the trunk, and reduce exposure to harsh afternoon conditions.

Usually, Acer japonicum 'Aconitifolium' needs little or no fertilizer when planted in reasonably fertile soil. If growth is weak or leaves show a confirmed nutrient deficiency, use a modest slow-release fertilizer in early spring rather than heavy feeding.

Potential pests include aphids, scale insects, and boring insects, although serious infestations are not inevitable. Inspect new growth and bark periodically, and address plant stress because drought and injury can increase pest problems.

Maple diseases such as Verticillium wilt can affect Acer japonicum 'Aconitifolium', and stressed plants may also develop leaf spots or dieback. Good drainage, avoiding root injury, and maintaining appropriate moisture help reduce problems, but wilted branches should be evaluated promptly.

Spring leaf loss is commonly caused by a late frost, which can damage tender emerging foliage. The tree may produce replacement leaves if the stems and buds remain healthy, but repeated frost exposure can slow recovery.

Plant Acer japonicum 'Aconitifolium' during dormancy, ideally in early spring or fall when the soil is workable and temperatures are moderate. Avoid planting during hot, dry weather or when the ground is frozen or waterlogged.

Dig a hole about twice the root ball’s width and no deeper than the root flare, then backfill with the native soil. Water thoroughly, keep the trunk flare above grade, and apply 2–3 inches of mulch without piling it against the trunk.

Young Acer japonicum 'Aconitifolium' plants can be transplanted more successfully than established specimens. Transplant during dormancy, preserve as much of the root system as possible, and provide consistent moisture while the tree re-establishes.

Acer japonicum 'Aconitifolium' is most reliably propagated by grafting or other specialist nursery methods. Seed may not reproduce the named cultivar consistently, so seedlings should not be expected to match the parent plant.

You can grow Acer japonicum from seed, but seedlings may differ from 'Aconitifolium' in leaf form, growth habit, and fall color. To preserve the exact cultivar, use a nursery-propagated plant rather than seed.

Prune Acer japonicum 'Aconitifolium' in late summer or during winter dormancy, removing damaged, crossing, or poorly placed branches. Avoid major spring pruning because maples may bleed sap heavily at that time.

No, it usually develops an attractive rounded or spreading form with minimal pruning. Limit pruning to structural correction, clearance, removal of dead wood, and occasional reduction of an unwanted branch.

No specific toxicity is well documented for Acer japonicum 'Aconitifolium', but ornamental plant material should not be eaten. Prevent children and pets from ingesting leaves, stems, seeds, or other parts, and contact a poison-control or veterinary professional if ingestion causes concern.

Acer japonicum 'Aconitifolium' produces small reddish to maroon flowers in early spring, often before or as the leaves emerge. The flowers are attractive close up but are not usually the plant’s main landscape feature.

Yes, it produces winged samaras that ripen from late summer into early fall. Seed production can vary by tree and growing conditions, and seedlings will not necessarily retain the cultivar’s distinctive foliage.

Its deeply divided green leaves can turn vivid orange, red, crimson, burgundy, or purple in fall. The exact color depends on genetics, weather, sunlight, moisture, and the timing of autumn temperatures.

It is called fernleaf maple because its palmate leaves are unusually deeply divided, giving them a fine, fern-like appearance. The cultivar name 'Aconitifolium' also refers to the resemblance of its leaves to monkshood foliage.