How To Identify Root Rot Before It’s Too Late

Root rot is one of the most common and destructive tree problems in Richmond and Central Virginia. Because most of a tree’s root system lies underground, it often goes unnoticed until the damage is severe—or irreversible.

The good news? When you know the signs of root rot, understand what causes it, and take quick action, your trees can often be saved—or even better, protected from rot in the first place.

In this blog, we’ll cover:

What causes root rot in trees
Signs and symptoms to watch for
Common fungi that rot tree roots
How to prevent root rot
Treatment options available

What Causes Root Rot?

Root rot typically begins in wet or compacted soil, where excess moisture creates a breeding ground for harmful fungi.

Some common contributing conditions include:

Poor Drainage or Constantly Wet Soil

Soils that don’t drain well allow water to pool around tree roots, starving them of oxygen and creating the perfect conditions for fungal growth. Even well-draining soils can become waterlogged after heavy rainfall, especially in low-lying areas.

Hidden Irrigation Leaks

In Richmond, one of the most overlooked causes of tree root rot is a damaged sprinkler or irrigation system. A cracked underground pipe or malfunctioning sprinkler head can leak water into the soil undetected. The lawn may appear normal, but beneath the surface, oversaturated roots are slowly being rotted.

Construction Damage and Soil Compaction

Root systems often stretch well beyond a tree’s canopy. Construction projects like patios, walkways, or pool installations—especially those involving heavy equipment—can crush and compact soil, damaging roots and cutting off their access to air and nutrients.

Even repeated mowing over the root zone can lead to soil compaction, increasing the risk of rot and fungal infection.

Signs of Root Rot in Trees

Wondering how to know if your tree has root rot? Look for these common symptoms of root rot:

Yellowing or wilting leaves
Out-of-season leaf drop
Stunted or slowed growth
Thinning canopy or bare branches
Dieback of upper limbs
Soft, discolored, or decaying bark near the base
Mushrooms or conks (shelf fungi) growing at the trunk base

If you see any of these signs—especially in combination—it may be time to call a certified arborist.

Fungi That Cause Root Rot

Two of the most common fungi responsible for root rot in Virginia trees are Phytophthora and Ganoderma.

Phytophthora Root Rot

This soilborne fungal-like organism attacks the root system and moves upward into the trunk. It thrives in warm, wet environments and often affects stressed trees or plants in poorly draining soils.

Look for:

Yellowing or wilting leaves
Out-of-season defoliation
Bark turning black where it meets the soil
Stunted tree growth

Ganoderma (Shelf Mushrooms)

If you see fan- or disc-shaped mushrooms growing at the base of a tree, it’s likely Ganoderma. These fungi produce “conks” that release spores and feed on decaying wood—weakening the tree from the inside out.

Ganoderma affects both hardwood and softwood species and is a serious red flag for internal decay and potential failure.

How to Prevent Root Rot

The best treatment for root rot is prevention. Keep your trees healthy and rot-free with these steps:

Ensure Proper Drainage

Avoid planting trees in areas where water naturally pools, and consider grading your landscape or installing drainage solutions if necessary.

Get Irrigation Systems Checked

Have a professional inspect your sprinkler or drip system for leaks or inefficiencies at least once per year—especially if you notice soggy spots or overly damp soil.

Avoid Pruning During Risky Seasons

Improper or poorly timed pruning can stress your tree and make it more susceptible to disease. In general, avoid pruning during fall, when fungi are most active. Late winter or early spring—before buds open—is often the safest time to prune most trees, helping support new, healthy branch growth.

Decompact the Soil

Soil decompaction or deep root fertilization helps break up heavy, compacted ground and improves airflow and drainage around roots.

Plan for Root Protection During Construction

Before building near a tree, consult a certified arborist to set up a root protection zone. This helps avoid cutting or crushing critical roots during excavation.

Can Root Rot Be Treated?

In many cases, yes—root rot can be managed or slowed with the right professional care. Early detection is critical.

Treatment Options May Include:

Professional-strength fungicide applications to the lower trunk and root flare
Soil decompaction or vertical mulching
Deep root fertilization to support recovery
Removing standing water or redirecting irrigation
Targeted pruning to reduce stress on affected trees

However, once a tree is structurally compromised or infected beyond recovery, removal may be the safest and most responsible option.

Contact Truetimber Arborists for Root Rot Help in Richmond

Think your tree might be suffering from root rot? Don’t wait for visible decline—by the time the signs are obvious, it may already be too late.

At Truetimber Arborists, we’ve helped Richmond-area homeowners care for their trees since 1998. Our ISA-Certified Arborists can diagnose root rot, recommend appropriate treatments, and provide guidance to protect your landscape in the long term.