What's eating my japanese maple 'dissectum'?

Acer palmatum var. dissectum (cut-leaf Japanese maple) is susceptible to the same pests as other Japanese maples — aphids most commonly, then scale and gall mites. Its finely dissected, congested foliage creates shelter for pests. Deer can shred the delicate leaves. Strong water blasts and good air flow inside the canopy are the best controls.

Congregate deep within the dissected foliage on new growth; honeydew and sooty mould can coat the lacy leaves, dulling their ornamental appearance. Direct a high-pressure water jet into the canopy. Open up the interior with light pruning to reduce humid hiding spots. Avoid oil sprays on Acer foliage.

Encrust stems and undersides of shoots with waxy or cottony bodies; prolonged feeding causes yellowing and branch dieback; harder to spot in dense, weeping growth. Inspect bare stems in winter and treat with horticultural oil. Apply a second spray timed to the crawler stage in late spring. Remove dead wood promptly.

Browse and shred the delicate dissected foliage, especially on plants under 1.5 m tall; antler-rubbing on the trunk can strip bark in late summer and autumn. Protect young plants with wire cages or tree guards. Deer-repellent sprays can reduce browsing but need regular reapplication, especially after rain.