You may have heard of a rash of cedar trees dying from Northern California into British Columbia. Trees in the wild don’t have the benefit of careful irrigation from humans and as our climate shifts to be drier in these areas, not all cedar trees can keep up. But the question remains: is that what your cedar tree is experiencing? In this guide, we’ll explore the reasons your cedar tree may be dying and what you try to do to save it.

1. Not Enough Moisture

The most common thing that catches people’s eye when their cedar tree is dying is that it turns brown, typically starting from the top and working its way down. Brown usually signals dryness. Cedars need wet conditions, and they have shallow roots that may not be able to find any water in a California drought. If you want to keep a cedar tree healthy in California, you require:

  • Irrigation: Your cedar needs to be covered by your irrigation system. Ideally, you’d have a drip irrigation system feeding the tree or a smart sprinkler system that can measure the moisture in the soil and keep conditions wet.
  • Mulch: Cedars are also used to consistent soil dampness, and in California you will need mulch to provide this and protect the shallow roots. Add several inches of mulch all around the tree—avoiding direct contact with the trunk.

If your tree is dying and it still has mulch and is getting regular water from an irrigation system, you simply may be experiencing drier conditions than normal. You likely will need to increase your watering schedule permanently.

Be sure you have the cedar’s moisture needs met before you tackle other health issues, as being too dry will make a cedar susceptible to everything else on this list.

2. Fungal Growth

Cedars aren’t the only thing that loves moisture, so does fungus. While cedar trees do have immune systems to protect themselves from fungus, some infections are just too intense. If you see small black dots on a dying cedar tree, it is infected. You can cut off the affected branches, ideally, before more than 20% of them are infected, and the tree should be fine. You can add antifungal spray to ensure the growth won’t continue.

3. Changing Soil Conditions

Cedars have shallow roots and will drain the topsoil of nutrients over time. Unable to reach lower, they may die off from lack of nutrients. Or, changing the pH of the soil to help support other plants can injure them as well. Add organic matter to the cedar’s base regularly, or apply a tree-specific fertilizer. Test your soil and ensure it is at the right pH for your specific cedar variety—most need highly acidic soil to function.

4. Crawler Mites

Crawler mites are small bugs that might be red, yellow, or brown. Any species of crawler mites can impact the health of your tree. Typically, you can just wash the bugs off with an insecticidal soap. However, getting to this problem early is important.

5. Root Rot

Armillaria root rot is a relatively common plague on cedar trees. It causes branches and needles to brown, usually on the top or one side of the tree first. Unfortunately, all trees with this rot eventually die. All you can do is confirm the infection and cut down the tree to prevent the rot from spreading and prevent the tree from falling dangerously.