Evaluate spruce, pine trees
By David G. Hallauer
Meadowlark District Extension Agent
For as attractive as they are in a windbreak or landscape, spruce and pine trees aren't well adapted to Kansas and other areas. High stress years like this one show us why.
If you are concerned about whether your trees have survived, now is a good time to evaluate. If the needles are browning on the inside of the tree, but needles farthest out on the branches remain green, you are likely seeing natural needle drop. It's a harmless and normal process during which two and three year old needles are shed.
If all the needles on a branch are turning color, that's bad. Could be pine wilt (on pine, not spruce). That's not good, but neither is the effects of heat and drought stress that may cause the same symptoms.
Check to see if the branch with browning needles is alive by scraping away a small area of outer bark with a sharp knife. Green tissue below the bark (the cambium layer) is a good sign. No green means the branch is dead. Check the ends of branches, too. Dry, brittle twigs are a sure sign that at least that part of the tree is dead. Remove dead wood, until the point when major removal harms the looks of the tree, then complete removal may be better.
The big thing is to reduce further stress with watering. During dry spells, including winter, water to a 10-inch depth (deeper preferred). Use a long rod to check the depth by pushing in to the soil. When you meet resistance, the soil below is likely dry. Trees need once a week watering when it's hot and dry. If the winter allows, water monthly when temperatures are above freezing.