I live in northern Italy.
After an incredibly hot summer last year and an invasion of ants around nesting around the base and running all over my red Japanese Maple, this year my poor tree is extremely slow in sprouting leaves (all the other Maples around here are fully covered with leaves) and a number of leaves with flowers are infested with black aphids.
There are already ants running around on the tree.
Help…. I really don’t want to use harsh insecticides.
Do you think a good harsh wash with a jet spray would help my tree?
The ants are likely farming the aphids for their sweet excretions. Sounds awful but it is a symbiotic relationship that exists between ants and aphids. To rid the plant of aphids, a strong stream of water will dislodge the aphids but not likely solve the problem. I recommend a mild solution of dish soap and water sprayed all over the leaves of the tree. Make sure to get all the leaves and under the leaves.
The ants are also problematic but you may need to spray them with ant killer as they would otherwise be impossible to remove. The spray you use shouldn’t harm the tree as the roots are far enough away that any rain water would dilute the poison before it reaches them.