Japanese Maple ‘Dissectum Garnet’ · Acer palmatum ‘Dissectum Garnet’

Compared to the green-leaved 'Dissectum' that is the better-known laceleaf cultivar in Portuguese specification, 'Dissectum Garnet' carries the same cascading dome architecture and the same finely cut leaf, but in a deep burgundy that establishes at bud-break and remains stable through the high summer before turning to crimson and burnt orange in October. The mature crown settles at around 2 to 3 m in height by 3 to 4 m in spread after roughly two decades of slow extension growth.

Growth rate is slow, which means a credible plant comes from the nursery as a multi-year specimen with torrão consolidated through repeated engorda cycles, not as a planting that will develop on site. The professional use case is the deliberate focal piece: a single specimen beside a water feature, an accent in a walled courtyard, the structural anchor of a low composition of ferns and acid-loving shrubs under light overhead canopy. It does not suit alignment, hedging, or volumetric mass planting.

Substrate requirements are strict. The species needs fresh, free-draining, humus-rich soils on the acid to neutral side; compacted limestone profiles and seasonally waterlogged ground both fail it within a season. The correct exposure is partial shade with morning sun. In Greater Lisbon (Cascais, Sintra, Setúbal peninsula), the Silver Coast, and Greater Porto, it performs reliably under light overhead cover. In the interior Algarve and the deep Alentejo, it must be reserved for sheltered courtyard positions or north-facing aspects: under full Mediterranean sun the dissected limb scorches at the edges and the wine-red weakens to a dull brown.

Hardiness reaches approximately -15 °C, with no Portuguese position presenting a winter limitation. Acer palmatum sits outside the active phytosanitary pressures relevant to the Portuguese market: the cultivar carries no exposure to Xylella fastidiosa, to the seca dos montados, or to pine wilt nematode. Maintenance is limited to a winter sanitary prune to remove dead interior wood; any formative or hard pruning destroys the cascading habit on which the cultivar's value depends.