|I bought 3 Dwarf Alberta Blue Spruce trees from Home Depot a little over a year ago, and planted them as instructed. They looked great and seemed to be doing well until recently. I am noticing browning of some of the needles.
Last fall I used Miracle Grow fertilizer spike for evergreens. I then also recently tried another powder fertilizer, but the condition seems to be persisting, if not getting
|Browning needles could indicate water stress or might be a sign of an insect called the spruce needle miner. If insects are present you'll see a tiny hole in each affected needle. Carefully inspect the needles with a magnifying glass. If you see no holes in the leaves, the browning may be caused by spider mites or insufficient water. To keep your spruces healthy, water them deeply once each week during the growing season. The easiest way to do this is to make a watering well or water basin beneath each tree. Fill the basin with water, allow to drain, then fill it a second time. This method of watering concentrates the moisture directly over the rootmass and allows it to trickle down and wet the entire rootmass. Spider mites like dry, dusty places and you can discourage them by periodically hosing off your spruces, directing a strong stream of water towards the center of the plant where the spidermites like to hang out. Best wishes with your spruces!