Half of My Tree Is Dead: What Causes It?

An alarming phenomenon you might encounter as a gardener is waking up to find that half of your tree is dead. One side seems as healthy as a horse, boasting lush greenery and vibrant blossoms, while the other side looks like a horror movie prop. Is this even possible? 

As the go-to crew for expert tree removal in Phoenix, we at Tree Workers of Phoenix have seen and addressed a wide range of arboreal oddities. Keep reading as we help delve into the root of the issue.

Tree Diseases

Let’s break down several disease-causing organisms that can wreak havoc on your living landscape:

  • Verticillium wilt, a common cause of ‘leaf damage‘ in trees, comes from a family of fungi that clogs plant cells. This disease leads to wilting, yellowing of leaves, and eventual death of the branches. Leaf damage is often an early sign of this condition, alerting gardeners to the need for prompt intervention.
  • Phytophthora root rot: Does the ground surrounding your tree stay excessively damp for prolonged periods? It’s the perfect breeding ground for Phytophthora, a mold that will make your specimen look drought-stressed.
  • Fusarium wilt: Fusarium oxysporum can lead your tree down a tumultuous path of decay. This soil-born pathogen infiltrates the roots and progressively impedes the tree’s ability to transport water.

Environmental Culprits

When half of your tree is dead, don’t be too quick to blame it solely on disease. Other factors might also have their hand in this arboreal chaos:


Did your area recently witness a thunderstorm? Mother Nature can pack a punch and lightning is no lightweight. A direct strike can cause severe damage to your tree, effectively frying half of it while leaving the other half relatively unscathed. 

Root Damage

Everyday endeavors such as landscaping, construction, or installing a new fence can inadvertently harm the exposed part of your tree’s root system. The stress may lead to a weakened immune system and make the tree susceptible to diseases and pests.

Soil Compaction

Ground compaction, often from poor soil quality, adds an unwelcome squeeze to your tree’s roots. This pressure severely limits access to vital nutrients, water, and air, leading to a slow strangulation. 

Even something seemingly innocuous like parking a car or setting up a hefty playset over the area can cause this. 

Unusual Growth Patterns

Check your specimen for unusually twisted or circular roots, also known as girdling roots. They often wrap themselves around the base of the trunk, constricting growth and giving otherwise healthy trees a quick demise.

Some even manifest under the ground, invisible to the untrained eye. That’s why it pays to keep a close eye on your garden for any sudden changes. 

What to Do When Your Tree Is Dying

When half of your tree is dead, delaying is not an option. Let our specialists at Tree Workers of Phoenix assess the situation.

We know how to diagnose sick or dying trees and provide the right treatment, from proper pruning to fungicide application. In severe cases, tree removal is the best solution to protect your property. Call our team at 602-320-2797 today for expert assistance. Explore more of our blog and discover the best time to have a tree removed.


Tree Workers of Phoenix has been in business since 1994 and is a member of the Better Business Bureau (BBB) and International Society of
Arboriculture (ISA).


18402 N. 19th Ave. #115

Phoenix, AZ 85023

Phone: 602-320-2797

Email : rickthetreeexpert@gmail.com

Hours of Operation :

Monday - Sunday : 9:00am-5:00pm


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