Mature southern magnolias commonly sprout from the stump and roots, so a magnolia stump should be ground below grade rather than cut flush and left. Expect a wide fluted base, roots that run far past the old branch tips, and bare, leaf-covered soil underneath that needs work before grass will take.
Magnolias do sprout
People expect a big evergreen to die quietly once it is cut. Southern magnolia does not. The Forest Service silvics manual says mature southern magnolia commonly develops root and stump sprouts, and that even when the tops are killed, the trees sprout vigorously. A magnolia cut flush with a saw and left will often put up a cluster of glossy shoots from the base within a season. A grinder working the stump down to four to eight inches under the soil, and outward through the flutes, removes the root collar those sprouts come from. A few shoots from roots farther out may follow; mow or clip them.
A fluted base and far-reaching roots
The silvics manual notes that older magnolias develop a fluted base, with ridges where the major lateral roots attach. That makes the stump wider at the ground than the trunk looked. Measure across the widest point of the flutes at soil level. Below ground, Clemson Extension says the roots of a mature southern magnolia may extend up to three times the reach of the limbs, and the University of Florida calls the root system wider spreading than most trees. The silvics manual describes the species as deep rooted, except on sites with a high water table. Grinding deals with the stump and flare; the spread of roots stays to rot.
The ground under a magnolia
NC State Extension says nothing will grow under a southern magnolia, which drops leaves in both fall and spring and needs a mulch to prevent erosion. The University of Florida notes that the large leaves decompose slowly. So when the tree and its stump are gone, the owner is left with a wide circle of bare, shaded soil covered in tough leaves, laced with roots. Rake the leaves off before the grinding, since anything lying there ends up in the chips. Then the spot needs soil and either seed or sod. Grass seed and sod after stump grinding covers that step.
Low limbs and access
NC State says magnolia limbs tend to reach the ground and that the tree can grow sixty to eighty feet tall and twenty to forty feet wide, which is why it advises a smaller cultivar for many suburban yards. When one magnolia comes out but another stays, its low branches can hang across the route the grinder needs. Tie them back or say so in the photos. The grinder runs on tracks and passes through an ordinary garden gate, approaching from the grass, so the main concern is clearance and the beds along the way.
Root sprouts after grinding
If shoots do come up from magnolia roots after grinding, they are evergreen and easy to spot in a winter lawn. Treat them like any root sprout: mow them with the grass, clip them low in beds, and do not let them grow leaves for long before cutting. Each cut takes a little more from the roots. Shoots that will not quit are worth a call to the county Extension office about a labeled product. How to stop stump sprouts covers the approach in more detail.
Smaller magnolias
Not every magnolia is a sixty-foot tree. Clemson lists saucer magnolia as a large shrub or small tree of twenty to thirty feet, star magnolia as a slow shrub or small tree of fifteen to twenty feet, and sweetbay as a mostly single-trunk tree of forty to fifty feet. The smaller ones usually sit in beds by the house, where the job looks more like an ornamental stump than a big one. See dogwood and ornamental tree stumps.
Grind it or take it out whole
Under a future lawn or bed, grinding is the right job. The roots left behind rot slowly and the lawn settles a little along the biggest ones. Take a magnolia out whole only when something needs the ground: a footing, a patio, a pool, a drive, or a new tree planted right where the old one stood. Given how far magnolia roots run, that is a sizeable dig, with a hole to backfill and let settle.
Common Questions
Will a southern magnolia grow back from the stump?
It can. The Forest Service silvics manual says mature southern magnolia commonly develops root and stump sprouts and sprouts vigorously even when its top is killed. With the base ground out under the soil line most of that sprouting tissue is gone; any root shoots that follow are mowed or clipped until they stop.
Why won't grass grow where my magnolia tree was?
Because nothing could grow under it. NC State Extension notes that magnolia shades out everything beneath it and drops slow-rotting leaves in spring and fall. After the tree and stump are gone, rake off the leaves, add soil over the ground-out spot and the bare circle, and seed or sod it once the light returns.
How far do southern magnolia roots spread?
Further than most trees. Clemson Extension says the roots of a mature southern magnolia may reach up to three times the spread of the limbs, and the University of Florida calls them wider spreading than most. Grinding removes the stump and flare. The rest stay in the soil and rot slowly.
What to Do Next
Show us the magnolia stump with a tape across the flutes, the bare ground under where the canopy was, and the route in, and tell us the town. Jordan quotes every job himself. Call (828) 574-4474.