Plant Problem Diagnosis Key / Growing conditions
Girdling roots and a buried root flare
A root that wraps around the trunk, or a trunk planted too deep or buried under soil or mulch, slowly strangles the tree. Decline often starts years after planting, when the trunk grows into the root, and runs over 5 to 10 years.
Signs
- No root flare: the trunk goes straight into the ground like a pole, or one side is flat.
- A root circling the trunk at or just below the soil line.
- Slow thinning, small pale leaves and early fall color, often worse on one side.
What favors it
Nursery trees planted too deep, roots circling in containers, soil or mulch piled against the trunk, and grade changes.
Prevention
- Plant with the root flare at or just above the soil surface; find it before you dig the hole.
- Cut or straighten circling roots at planting.
- Keep mulch 2-4 inches deep and pulled back from the trunk.
Crops it shows up on
Shade & ornamental trees; Evergreens & conifers (pine, spruce, juniper); Apple, pear & stone fruit.
Often confused with
Sources
- Girdling RootsUniversity of Maryland Extension
- Deep Planting/Grade ChangeMontana State University Extension
- Are tree roots wrapped around the tree trunk a concern?Purdue Extension
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
No, only damage or discoloration - Where is the problem?
A tree or shrub - Which part of the tree or shrub shows the problem?
The base of the trunk or the roots - What do you see at the base?
No flare, or a root wrapping around the trunk
Not a match? Start the key or describe what you see.
More photos
More from university Extension: search Extension pages on girdling roots and a buried root flare, or find a plant diagnostic lab through your state's Extension.
Other growing conditions
- Blossom drop
- Blossom-end rot
- Cold and frost injury
- Construction and root damage
- Drought stress (underwatering)
- Edema (oedema)
- Fruit cracking
- Heat and light stress
- Herbicide injury
- Leaf scorch and drought stress
- Light bleaching
- Mower, trimmer and animal injury
- Normal fall needle drop
- Not enough light (stretching)
- Overwatering (low root oxygen)
- Road salt injury
- Southwest injury (winter sunscald and frost cracks)
- Sunscald
- Transplant shock
- Winter burn of evergreens