Asked June 21, 2020, 2:21 PM EDT

I purchased a healthy, beautiful large Alulition (Red tiger Japanese maple) and planted it in organic soil with some organic long acting fertilizer as I hear this plant is a heavy feeder. The leaves, especially the new growth, are being eaten. I have applied diataomceous earth and sevin liquid. Still no help. Also ants are living in the soil. Please advise. I don’t want to lose this beautiful plant. Thank you.

Lane County Oregon

3 Responses

Before applying pesticides of any kind, it is really important to find and identify the pest.

The interveinal feeding and time of year of this damage makes me suspect that slugs or snails might be to blame. Slugs and snails most often feed at night, so it can be difficult to catch them 'in the act'.

Is it possible for you to go out at night, with a flashlight, to see if you see who might be feeding on the leaves? If that is not possible, can you place some a board trap in the vicinity of the affected plant? A board trap is simply a small board, placed near the affected plant. It provides shade and moisture that slugs like. Check the board early the next morning, to see if slugs or snails are underneath. If you find slugs or snails are the culprit, I would recommend safe application of a slug or snail bait (iron phosphate is less harmful to wildlife and pets, compared to metaldehyde baits), ollowing all label recommendations, would be my advice. If slugs or snails are not found, we need to go back to square one, and try to determine what is causing the damage.

Hi Gail,

Thanks, i will look for any slugs or snails. i know i have them in other areas of the garden, in my hostas and peace lilies. I do use sluggo around the areas i know have slugs and snails. i have not seen any slimy lines on the large pot this plant is in so far, I have only seen the ants marching in lines up and down carrying little white things in their mouths. But I will try that tonight. thanks.

Thank you for your quick reply.

The ants on the tree suggest that the tree might have scale insects or aphids. But, neither of those insects (or the other phloem-feeding insects that attract ants) leave large holes in the leaves.

A leaf-feeding beetle, such as Japanese Beetle, can cause the large holes on the leaves. But, we don't have those beetles in our area.

Looking forward to hearing if you find slugs or snails, in the evening, or if a closer look at the underside of the leaves might reveal the true culprit.