Why are my Conifers Turning Yellow?

In late winter and early Spring a common occurrence with newly planted conifers is that their needles turn a light green or yellow color.   This occurs even though they looked fine going into fall and winter.

There are quite a few possible reasons for this - some of them are even completely normal.

1) Seasonal Needle Drop (Normal)

All spruce and Pines shed older interior needles in fall.  If this is the case, yellowing starts on inside needles, not the tips.  Current year’s growth will stay green.  This happens in late summer into fall and is completely normal.

2) Winter Burn

Winter burn is common after harsh northern winters.  It's noted by yellow to brown needles on the south or wind-exposed side.    If winter burn is the culprit the damage will show up as we approach spring, and is often worse on young/stressed trees.   It's caused by winter sun + frozen soils (roots can't take up water to replace the moisture lost).   Unless it's a severe case it's mostly cosmetic - the buds are still alive and the damage will be replaced by new growth in Spring.  If the leader is dead or more than 50% of the tree is brown then survival is less likely.

3)  Drought Stress

Newly planted conifers hate dry conditions.  If it was a dry summer/fall and they are overall pale or yellow cast, this is a likely culprit.   They may also have a thinning canopy and have more needle drop than usual.    It's important to make sure newer plantings have adequate moisture going INTO winter.  If they are just yellowing a bit they most likely will send out new growth in Spring.  If they are dark yellow or turning brown the prognosis is more grim.  But you'll know for sure in April/May.

4)  Poor Drainage / Root Rot

Many conifers do not tolerate wet feet all the time (some like Black Spruce or maybe White Spruce do).   If the soil stays wet for long periods and you see uniform yellowing/stunted growth this is the most likely culprit.

5)  Nutrient Deficiency (Usually Nitrogen or Iron)

If your Spruce are overall a pale green or yellow color and are growing very slowly this is a common cause.   It's more common in high pH soils.   You can help them along with a balanced or targeted fertilizer.    To know exactly what is recommended you need to know your pH and a soil test is super helpful.    Please note:    We do not provide specific fertilization recommendations - that is entirely dependent on your specific soil conditions.     We work with the county extension offices on our land.  We provide a soil sample and get very specific recommendations on what is needed based on our soil composition.

6) Other Possibilities

There are other possibilities that are less likely like Needle Cast Disease, Spider Mites, or Herbicide drift.    But they are less likely scenarios.