Preventive Controls
Healthy hemlocks can tolerate adelgids better than can trees in poor health. Prophylactic steps can be simple:

1. Mulch to maintain soil moisture.

2. Irrigate during periods of extended drought.

3. A strong jet of water may knockoff a lot of adelgids if done in spring or fail when the insects are active.

4. Organic treatments which have shown promise include soil demineralization, compost tea and certain bacterial & fungal applications. Find a professional who specializes in this approach. Nitrogen fertilizer should NOT be applied because it enhances adelgid survival Recovery of trees treated with insecticides may be assisted with moderate applications of fertilizers that address specific nutrient.

5. Bird feeders should not be placed near hemlocks because birds spread adelgids.

6. Removing isolated infested tines may also help to slow the spread of HWA.