Fall Deep Root Feeding: When and How to Fertilize Trees and Shrubs

As temperatures drop and trees shed their leaves, the work below ground isn’t necessarily over. For turf managers overseeing properties with trees and shrubs, fall offers an opportunity to support plant health with deep root feeding. To make the most of this seasonal opportunity, it helps to know when to apply, what to avoid, and how to time it well.

Why Deep Root Feeding Makes Sense in Late Fall

Roots can remain active as long as soil temperatures and moisture conditions are favorable. Instead of leaving fertilizer on the surface, soil injection places nutrients directly into the areas where roots are growing. This method is particularly beneficial for golf courses and residential properties where tree roots extend beneath maintained turf.

When plants need additional nutrients, applying fertilizer in late fall can replenish the reserves they will need as growth resumes in the spring. Since the plant is no longer focused on producing leaves and shoots during this period, it is an ideal time to address its nutritional needs without promoting excessive late-season growth.

A Few Things to Consider Before Applying

1. Wait until the trees are ready. For deciduous trees and shrubs, leaf drop is a useful sign that the plant is entering dormancy. Applying too much nitrogen before this transition can encourage tender new growth that freezing temperatures may damage. For fall feeding, focus on meeting the plant’s nutritional needs rather than producing a visible growth response.
2. Don’t stop at the drip line. Tree roots often extend well beyond the canopy’s outer edge. When planning injection points, consider the full area where roots may be growing, not just the ground directly beneath the branches. Spread applications across accessible rooting areas instead of concentrating them near the trunk.
3. Check the ground before bringing out the equipment. A little soil moisture is helpful, but saturated ground is another story. If the soil is waterlogged, frozen, or extremely dry, postpone the application. Roots need suitable soil conditions to remain active, and poor conditions can also interfere with proper fertilizer placement.
4. Some trees are better left untreated. Not every tree needs additional fertilizer. Healthy, established trees with adequate nutrition may see little benefit from another application. Newly planted trees or shrubs installed this season should not receive deep root feeding. Evaluate plants struggling with drought, disease, or damaged roots individually before treatment. When possible, use soil test results and visible plant conditions to determine whether fertilization is appropriate.

Support Fall Deep Root Feeding with Foliar-Pak

Foliar-Pak offers solutions that support root health, nutrient availability, and soil biology.

Ultimate Ornamental Package

Foliar-Pak’s Ultimate Ornamental Package (UOP) consists of three products—Chloroburst L, Bio 12-6-6, and Colonise Bio LTO. This package provides essential support for trees and shrubs in several key ways:

• Introduces beneficial soil microbes
• Supports robust root systems
• Aids plants in producing their own food
• Enhances the uptake of water and nutrients
• Promotes overall plant health without encouraging delicate top growth before winter

Grow-In

For turf managers looking for a simple solution, Foliar-Pak Grow-In combines plant nutrition with Armament®, AminoPrecise®, and Colonise® technologies to support rooting, establishment, nutrient availability, and overall plant performance.

Directions for applying Grow-In in a deep root feeding tree and shrub application:

• Mix 2 gallons of Grow-In with 100 gallons of water
• Apply 1 gallon of solution per inch of trunk or shrub diameter
• If turf is present, inject the solution straight into the soil

Stronger Springs Start Below Ground

Healthy trees and shrubs contribute to the landscape’s overall appearance and value. Fall deep root feeding gives turf managers another chance to support plant health and prepare trees and shrubs for the coming growing season. With the right timing, application practices, and Foliar-Pak solutions, attention below ground now can help you set the stage for success next spring.

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