Christie’s Blog

March 2025

Girdled Tree Roots:

Consider Deep Root Feeding

I have waited since last Spring to cut back the roots on my girdled maple trees. With winter, the trees are finally dormant. When my good friend and “tree” man checked them out.  He said the girdled roots on my tree supported the trees in a big way.  If I cut the supporting roots that are girdling the tree, the whole tree may fall over!

What are  girdled tree roots?

A girdled tree root is a root that grows in a circular or spiral pattern around the trunk or below the soil line.  This gradually strangles the trunk, and slowly deprives the tree of moisture and oxygen.

Why does Girdling Occur?

Problem #1 : The tree is planted too deeply. Sometimes the tree looks like it’s planted high enough. Keep in mind that the soil around and under the tree will compress with time and sink the root ball more deeply.

Solution: Plant the tree about 2 inches above ground grade and even higher if it’s a wet area.

Problem #2: The tree is planted in too small a hole so the roots cannot easily spread out. People who plant sometimes just get tired when digging a hole and make it too small.

Solution: Dig a hold at lease twice the size of the root ball. The research now suggests that a rectangular shaped hold is best because its easier for the roots to reach away from the circular pattern of the pot and hole.

Problem #3: Some container grown trees that have roots growing in a circular pattern.  If a plant has been sitting in its pot a few seasons this easily happens.

Solution: Break up the root ball a bit with your hand or scrape the root ball lightly with your pruners or knife to cut  the circular pattern.

Problem #4: Planting a bare root tree by twisting roots to fit in a small hole. There is no dirt around the tree root to help gauge how big the hole should be.

Solution: Dig a bigger hole and stake the tree on a few sides to help it stay upright.

Problem #5:  Leaving a wire baskets, burlap or any part of a container in the planting hole can cause girdliing.. They used to tell you to leave the basket and burlap on the tree when you plant!

Solution: Remove the basket and burlap and massage the root ball if you see a circular pattern.

Problem #6: Piling mulch agains the trunk of a tree creating a mulch volcano.  This happens over time.

Solution: Pull mulch away from  actual tree trunk by an inch or tree. Mulch very lightly on tree roots.

Symtoms and diagnosis

1. Scorched early fall color and early leaf drop. Damage to one or two branches.

2. Abnormally small leaf size.

3. Lots of twig dieback and the appearance of large, dead , leafless branches.

4. Thin appearance the crown (foliage bearing section of the tree) and overall stunting.

5. Little or no trunk taper at the collar.

6. Leaning.

7. Susceptibility to environmental extremes (uh-oh) and other biotic problems.

One solution, that does not cause a million dollars, is to deep root feed the tree. Hopefully giving the deep roots more organic food and micronutrients  helps offset girdled roots.

How to deep feed a tree

Root tree feeders are easy to buy and nowadays involve putting fertilize in water and shooting down a tube to the roots.  I’m sure this is a more gentle and speedier approach than what I am writing next.

The old time method of feeding the roots is to get the area around the tree damp then with root feeder and pound the metal tube into the ground making about 4-6 holes around the mulch line a good distance away for the tree trunk and main roots.

Pour in a granular product such an organic slow release 14-14-14 with micro nutrients . I do not suggest the stiff / dense root feeder stakes. I think it is easier for a granular product to break down and feed the root rather than a hard root stake.

Anytime from late winter to early spring is a good time to feed. It gives the tree a good send off for the coming season and gives us a feeling of being helpful in a dire situation.

Christie lives in Manakin Sabot , Virginia where she manages a 3 acre garden. Her blogs are written from her 35 years as a personal and professional gardener.