Hi, I submitted this question last week but nit sure it really went through, so here it is again.
I’ve had a Hewitt’s PomPom for a couple years. It thrived until last summer, when a large amount of needles started turning brown and dying. I asked about this at the store in Glens Falls, and it was suggested I apply an insecticide. Which I did, spraying on needles and also applied under the tree for the roots. The browning did not stop and continued to spread to new areas of needles. Now already this spring more areas are turning brown. The Glens Falls store manager suggested I write to you for any help you might offer, before the tree completely dies.
The first thing to check is to get down under the plant and check to make sure that you didn’t bury the stem too deep at planting time or that you haven’t piled mulch up against the trunk of the tree. Brush any mulch and soil away from the trunk until you find the original soil level on the trunk when it was in the pot or ball that it came in. Soil or mulch piled against the bark hinders or stops the flow of moisture and nutrients from the roots below to the branches above…basically slowly strangling the tree to death. Planting too deep and/or piling mulch against the bark is the most common reason recently planted shrubs and trees die and are brought back for replacement. Brush the soil and mulch back to the original soil a few inches away from the trunk and keep it that way. Feeding it with some Holly-Tone evergreen food will help it recover as well. You can send pics to firstname.lastname@example.org