How to apply neem soil drench

[Graeme]

Hi

At my Bridge club we have some rhododendrons, lemon trees and viburnum plants that have been affected by thrips and white fly. I have sprayed with horticultural oil and neem and also used neem soil drench. I am unsure about how to apply the soil drench though. What I currently do is on opposite sides of the plant I make a patch of bare soil roughly 3 inches by 4 inches just inside the drip line and apply 1 to 2 cups of solution to the bare soil. Is this the right way to do it or do I need to try and encircle the entire plant? I am using some stuff called "neem insecticide" at 10 mls per litre on the advice of the manufacturer.

 

[Chuck]

Neem Oil when used as a drench acts as a systemic insecticide, meaning that it is absorbed into the plant through the roots and when an insect takes a bite it is poisoned. Use 1 oz per gallon of water and drench the ENTIRE root system. In my experience a Neem drench is somewhat iffy, meaning that it works but not 100%. You will probably still need to foliar spray. If thrips are a serious problem a garlic spray works really well. With whitefly not so much.