A tree stump, the remnant of a felled tree, often presents a puzzle to homeowners wondering if the tree is truly gone. The answer depends heavily on the species of tree and the biological mechanisms still active beneath the soil. While some stumps quickly decay, others possess a remarkable capacity to regenerate new growth. Understanding this survival instinct is the first step toward managing a property after a tree has been removed.
Trees Prone to Sprouting
Deciduous trees are the biggest culprits for persistent regrowth, having evolved robust survival mechanisms. These trees often regenerate through two distinct methods: suckering and epicormic sprouting. Suckering involves the growth of new shoots directly from the lateral root system, sometimes appearing several feet away from the main stump. Epicormic sprouting is the emergence of new growth from dormant buds located on the stump itself, particularly around the root collar.
Common species known for vigorous regrowth include maples, willows, poplars, elms, and certain types of oak trees. Fruit trees, such as cherry and apple, are also highly likely to send up new shoots from the remaining rootstock. This capacity for regeneration is so pronounced in some species that it has been traditionally exploited in forestry practices like coppicing, where trees are intentionally cut to the base to encourage multi-stemmed regrowth.
Most conifers, like pines, firs, and spruces, generally do not exhibit this kind of regrowth from the stump. These trees lack the necessary dormant buds on their older, woody trunks and consequently cannot initiate new shoots when cut back to the base. For the majority of evergreens, cutting the tree down is sufficient to prevent new growth.
The Biology of Stump Survival
The ability of a stump to sprout new growth hinges on the root system’s stored energy. Even without a canopy for photosynthesis, the roots of a living stump contain substantial reserves of carbohydrates. This stored food acts as the fuel source for the initial burst of new growth. The stump attempts to quickly re-establish a leaf surface to begin producing its own energy again.
The mechanism of sprouting involves the activation of dormant or latent buds. These undeveloped buds are typically suppressed by growth-regulating hormones, such as auxins, produced by the actively growing tips of the main tree trunk—a phenomenon known as apical dominance. When the trunk is removed, the source of these inhibitory hormones is lost, releasing the dormant buds from suppression. This allows the buds, particularly those located at the root collar, to rapidly activate and form new shoots.
Stopping Stump Regeneration
To ensure a tree is truly gone and prevent unwanted regeneration, the most effective strategies involve eliminating the stored energy reserves and preventing bud activation.
Stump grinding is one of the most popular and thorough methods. This mechanical process uses a specialized machine to shred the stump down to below ground level, typically 6 to 18 inches deep. Grinding physically removes the root collar and the source of the latent buds, along with a large portion of the energy-rich root flare.
Another approach involves the application of a systemic herbicide, which is absorbed into the vascular system and transported to the roots to kill the remaining living tissue. For maximum effectiveness, the herbicide must be applied directly to the fresh, living cambium layer—the thin, moist ring of tissue just inside the bark—within hours of cutting the tree. Applying the product to the outer ring of the freshly cut stump allows the poison to be translocated down into the root system before the wound seals itself.
A slower, non-chemical method involves smothering the stump to exhaust its energy supply. This is achieved by covering the stump with a thick, opaque material to block all sunlight. By preventing new shoots from accessing light for photosynthesis, the root system is forced to repeatedly use its stored carbohydrates. Over several months to a year, this repeated effort depletes the root system’s energy reserves, leading to the eventual death of the stump.