By September, visible growth slows, and leaves may start changing color. Below ground, however, tree roots can remain active while soil conditions are favorable. During this period, trees continue absorbing moisture, developing fine roots, and storing resources that support winter survival and spring growth.
Fall tree watering, fertilizing to supplement soil nutrients before winter, and other fall tree care help to support root health before winter. Read on to learn more about what your roots are doing in fall and how you can maintain their health.
Do Tree Roots Continue Growing in the Fall? Why Root Activity Continues After Leaves Begin Changing
Above ground, tree leaves may change color and fall as trees enter dormancy, but below ground, roots are still working hard to prepare trees for winter.
Root activity slows progressively as temperatures cool. Because soil cools more slowly than the surrounding air, root activity can last weeks longer than the growing season. In this time, fine roots experience secondary growth as soil becomes moister and temperatures moderate, allowing additional nutrient uptake and storage to prepare for winter. Carbohydrate storage is especially important during this time because it provides the energy needed to keep tree roots alive and support new growth
Keep in mind that root activity varies with soil temperature, moisture levels, species, and site conditions. For example, Cape Cod’s coastal climate allows soil to remain workable later than soil located further inland.
Why Fall Root Health Matters for Winter and Spring Growth: Healthy Roots Now Support a Stronger Growing Season
It’s generally well-known how roots deliver water and nutrients to trees. But the root’s condition affects the tree's ability to take up water and nutrients from top to bottom. Root condition influences:
Spring bud development and leaf out
Flowering and shoot growth
Recovery from summer drought
Resistance to opportunistic pests and diseases
Anchorage and structural stability
The ability to tolerate winter desiccation and freeze-thaw conditions
Fall root and tree care support long-term resilience but does not guarantee protection against all winter injury. Newly planted trees, for example, have limited root systems and need extra seasonal care.
What Can Limit Tree Root Growth During the Fall? Common Soil and Site Problems That Restrict Root Development
Soil and site conditions are paramount to root health, especially in the fall. Unhealthy soils can stop roots from getting enough oxygen, water, and nutrients, leading to weaker growth. Watch out for these common site and soil issues:
Dry soil – Cooler weather can mask inadequate soil moisture. Short, heavy rainfall may run off rather than soak deeply into compacted or sloped ground.
Compacted soil – Compaction limits oxygen, water movement, and the physical space roots need to expand.
Buried root flares and girdling roots – Excess soil or mulch around the trunk can hide root defects and interfere with normal root function and lead to rot or pest issues.
Construction and grading damage – Driveway work, trenching, equipment traffic, and grade changes can injure or remove roots.
Poor drainage – Waterlogged soil displaces oxygen and can contribute to root decline.
Nutrient or pH imbalances – Fertilizer should not be applied automatically. Soil conditions and tree health should guide treatment decisions.
How to Support Tree Root Growth from September Through November: Fall Tree Care That Helps Build Strong Root Systems
Watering and mulching are two key factors that can help support root systems in the fall. Start with a professional soil test if trees show poor growth, premature color, chlorosis, or repeated decline.
Watering – Continue watering despite rainfall, as most rainfall is insufficient. Prioritize trees planted in the past few years, evergreens, shallow-rooted trees, trees affected by summer heat or drought, trees growing in sandy Cape Cod soils, and trees planted near pavement or compacted areas. Check soil moisture before watering, but the general rule is 1 inch of water per week for clay soils and 2 inches for sandy soils. Water slowly, ideally with drip irrigation rather than overhead sprinklers.
Mulching – Maintain a proper mulch ring by applying a 2- to 3-inch-thick layer over the root zone, keeping away from the trunk and root flare. Extend the mulch outward toward the dripline. Avoid adding new mulch without checking the existing depth.
Avoid parking vehicles beneath trees, repeated foot or equipment traffic, storing stone, soil, or materials over roots, and excavating within the root zone without professional guidance to protect tree roots.
Does Fall Fertilization Help Tree Roots? When Fertilization Supports Root Health and When It Does Not
While beneficial, fall fertilization works best as part of a long-term plant healthcare strategy, not as a one-time winter safeguard.
Soil testing and tree condition should guide whether a tree needs fertilization and what nutrients it needs. If a tree is severely stressed, waterlogged, or diseased, it may require correction before fertilization.
Slow-release fertilizer works best for nutrient absorption deep within the roots over longer periods.
When Fall Root Problems Require a Certified Arborist: Signs the Problem Goes Beyond Seasonal Maintenance
If a tree shows premature fall color or leaf drop, repeated sparse canopy growth, mushroom or fungal growth near the base, and general decline despite adequate watering and mulch, it may have more serious underlying issues that require professional assessment as part of your winter tree preparations.
A certified arborist may recommend soil testing, root-collar excavation, air excavation, decompaction, drainage correction, or a broader plant health care program.
Certified arborists can also help with soil heaving or a recent change in tree leaning, standing water around roots, and construction or excavation near a tree.
At Hartney Greymont, we have local arborists throughout Massachusetts in Needham, Concord, Danvers, Cape Cod, and the surrounding areas with the expertise needed to keep your trees healthy year-round.
Protect your trees before winter! Schedule a fall root and soil health assessment with a Hartney Greymont certified arborist today.
FAQ: Fall Tree Root Growth in Massachusetts
Root activity may continue after leaf drop while soil remains sufficiently warm, moist, and aerated. The exact timing varies by species, soil type, location, and seasonal weather.
Water when soil several inches below the surface is dry, particularly for newly planted trees, evergreens, shallow-rooted species, and trees affected by summer drought. Water with a soaker hose or at ground level; sprinkler systems tend to focus on turf and can stress trees and shrubs. Continue until the ground begins freezing, but avoid saturating poorly drained soil.
Proper mulch helps conserve moisture and moderate soil temperatures. Spread it over the root zone without contacting the trunk or burying the root flare.
No. Fertilization should be based on tree condition, soil testing, species needs, and site conditions. Watering, decompaction, drainage correction, or root-collar care may be more important than fertilizer.
Slow water infiltration, hard soil, sparse canopy growth, premature color, and poor annual growth can indicate compaction. A quick home test that includes driving a long screwdriver into the soil with your palm can help determine compaction, but a professional inspection can confirm whether the root zone needs decompaction or air excavation.
