It is better to start preventive fungicide sprays in March to protect the spruce form needle cast or needle drop. Reapplication should be done every 7 to 10 day through mid May to protect the tree. Rain will wash the fungicide off the tree reducing its effectiveness.
It is also recommended to remove the old dead needles and twigs from under the tree to reduce potential for spores to reinfect the tree. The lower limbs will not continue to grow out once the tip is dead and can be cut back to the trunk. Fresh mulch can be applied under the tree.
For more information contact the Oldham County Extension Service Office.