Q : Moths are doing damage to our Birch Tree. We had the tree sprayed and it seemed to kill off the moths. However it was recommended that just before spring use imidacloprid via soil injection. What concentration do we use and how do we inject it into the soil?
A : The best product to use for such treatment would be Merit 75.
Recommended Application for Trees:
0.7 to 1.4 level teaspoons of Merit 75 WP per inch of trunk diameter (D.B.H.) or 1 to 2 ounces per 30 cumulative inches of trunk diameter (D.B.H)
GRID SYSTEM: Holes should be spaced on 2.5 foot centers, in a grid pattern, extending to the drip line of the tree
CIRCLE SYSTEM: Apply in holes evenly spaced in circles, (use more than one circle dependent upon the size of the tree) beneath the drip line of the tree extending in from that line.
BASAL SYSTEM: Space injection holes evenly around the base of the tree trunk no more than 6 to 12 inches out from the base. Mix required dosage in sufficient water to inject an equal amount of solution in each hole. Maintain a low pressure and use sufficient solution for distribution of the liquid into the treatment zone. For optimum control, keep the treated area moist for 7 to 10 days. Do not use less than 4 holes per tree