Question
I have searched the net and found that the use of certain phenoxy herbicides under spruce trees might cause curl of branch tips.  What is the possibility of a spruce recovering from such damage?  The Colorado Blue Spruce trees in question are located on a south bank with water supply moving away from them downhill and are currently being watered frequently in order to flush the soil of any residual herbicides.  I thought that 2,4-D had very little residual effects only lasting in the soil for up to 2 weeks.  If the soil is properly flushed of this herbicide, what are the odds that the damanged spruce trees will survive?  I have read multiple herbicide labels, in particular Hi-Dep which says nothing about the possibility of damaging root systems of spruce trees if treating under them for dandelions.  Since the above mentioned trees were spot treated underneath for dandelion control, is it possible that they could suffer irreparable damage?  Can you address these issues, please.

Answer
More than likely you will not get any damage from the sprayed herbicide unless you got it on the foliage. 2,4-D will not damage the roots of trees. Liquid herbicide for lawn weeds can be used around trees if it is kept off the foliage. Granular herbicides including Weed and Feed fertilizers will be absorbed by the root and cause damage. i would not be too concerned with this application--the very worst would be loss of a some foliage that was sprayed. And in that case the tree will recover. There will be no up take by the roots system of these liquid herbicides.