Nutrients injected directly into the root zone, past the alkaline clay that blocks surface-applied fertilizer from reaching your trees.
Most trees in Davis County are not starving because the soil lacks nutrients. They are starving because the soil locks those nutrients away. Alkaline clay at pH 7.5 to 8.5 makes iron unavailable to roots. Surface-applied fertilizer sits in the top few inches where lawn grass intercepts it before it reaches tree roots. Deep root fertilization solves both problems. We inject a liquid nutrient blend directly into the root zone at 4 to 12 inches deep, where feeder roots can absorb it immediately.
The soil along the Wasatch Front is alkaline clay with a pH between 7.5 and 8.5. At that pH, iron becomes almost completely unavailable to plants. Iron solubility drops dramatically with every point of pH increase. By the time soil reaches pH 8.0, which is typical in Davis County, there is not enough available iron for most trees to stay healthy.
The soil is not missing iron. It is there. But alkaline conditions lock it into forms that roots cannot absorb. Calcium carbonate throughout the soil profile keeps the pH high. Adding acidic amendments to the surface does not help because the soil buffers back to its original pH.
Clay compaction makes it worse. Dense soil restricts root growth and limits how much water and oxygen reach the root zone. In older Davis County neighborhoods, decades of foot traffic and mowing have compacted the soil around trees. Nutrients applied to the surface cannot penetrate the compacted layer.
On top of all that, lawn grass competes for anything that does make it into the top few inches. Tree roots grow deeper, but surface fertilizer rarely reaches them. The grass gets fed. The tree does not.
Deep root fertilization uses a soil injection probe connected to a hydraulic pump. The probe is inserted into the ground at multiple points around the tree. At each point, a pressurized liquid fertilizer blend is injected directly into the root zone.
Where we inject. We place injection points in a grid pattern starting several feet out from the trunk and extending to the drip line. The drip line is the outer edge of the canopy where feeder roots are most active. Points are spaced about two and a half to three feet apart. A small tree may need 4 to 8 injection points. A mature shade tree with a 12-inch trunk may need 25 to 30.
How deep. The probe goes 4 to 12 inches below the surface. This is where 90 percent of a tree’s absorbing feeder roots live. Deeper than surface fertilizer can reach. Below the compacted clay layer. Past the zone where lawn grass intercepts nutrients.
What the pressure does. The liquid is injected under pressure. This does two things. It delivers nutrients directly to roots. And it fractures compacted clay around each injection point, creating channels for water and oxygen to flow. That soil loosening is a secondary benefit that helps the tree even after the nutrients are absorbed.
What we inject. The blend includes nitrogen, phosphorus, potassium, iron, and micronutrients. We adjust the formula based on the season and the tree’s condition. The iron we use is a chelated form that stays available to roots even in alkaline soil. Standard iron fertilizer from a garden center breaks down in high-pH soil before roots can use it. Chelated iron is protected by a molecular shell that keeps it in a form roots can absorb.
If your tree has yellow leaves with green veins, that is iron chlorosis. It is the most common nutrient deficiency in trees along the Wasatch Front. The tree cannot absorb enough iron from the alkaline soil to produce chlorophyll normally. Leaves turn yellow or pale green while the veins stay darker. In severe cases, leaf edges turn brown and die during hot weather.
Iron chlorosis gets worse over time. A tree that shows mild yellowing one year may develop branch dieback the next. Left untreated over several years, chlorosis can kill a tree.
Trees that are most susceptible in Davis County. Some species handle alkaline soil better than others. The trees most likely to develop iron chlorosis in our area include silver maple, red maple (especially Autumn Blaze and Autumn Fantasy), pin oak, river birch, sweetgum, and quaking aspen. USU Extension specifically warns that aspen is native to higher elevations with lower soil pH and is not well adapted to the low-elevation sites where it is commonly planted in Davis County.
If you have any of these species in your yard and the leaves are yellowing, iron chlorosis is the most likely cause. Deep root feeding with chelated iron directly addresses the problem.
Trees that tolerate alkaline soil well include honeylocust, hackberry, Kentucky coffeetree, ginkgo, most elms, catalpa, and Canyon maple. These species rarely develop chlorosis in Davis County conditions.
Not every tree problem is a nutrient problem. But these signs point to trees that would benefit from deep root fertilization.
Yellow leaves with green veins. This is iron chlorosis. It is the clearest sign that your tree cannot get what it needs from the soil. It shows up most on silver maples, red maples, and pin oaks in Davis County.
Thin or sparse canopy. If your tree produces fewer leaves than it used to, or the canopy looks thinner year after year, the tree may be nutrient-deficient. Compare it to similar trees nearby. If theirs are full and yours is not, feeding is likely needed.
Slow growth. A healthy shade tree adds visible new growth each year. If branches have stopped extending or the tree seems stalled, nutrient deficiency in compacted clay soil is a common cause.
Dead branch tips. Dieback at the ends of branches, especially in the upper canopy, often signals that the tree has been nutrient-stressed for multiple seasons.
Sticky residue or black coating on leaves. This is honeydew from aphids. While aphids are an insect problem (treated separately), a tree weakened by poor nutrition is less able to resist insect stress. Feeding and insect control work together.
If you are seeing these signs, contact us for a free evaluation. We can determine whether deep root feeding, insect treatment, or both are needed.
We apply deep root fertilizer in two seasonal windows. Each serves a different purpose.
Spring (late March through mid-May). This is when trees come out of dormancy and push new leaf growth. Demand for nitrogen and iron is highest. Spring feeding supports canopy development, green color, and overall vigor for the growing season. For trees with iron chlorosis, spring is the best time to get chelated iron into the root zone because uptake is strongest at bud break.
Fall (late September through November). After the canopy stops growing, roots remain active below ground. Trees shift energy toward root expansion and nutrient storage for winter. Fall feeding with a blend higher in phosphorus and potassium builds the reserves that fuel next spring’s growth. Trees that go into winter well-fed come back stronger.
When we do not feed. We avoid deep root feeding during the heat of summer (June through August). Hot weather combined with fertilizer salt can stress roots. We also do not fertilize newly planted trees in their first growing season. New trees need to establish roots before they can handle added nutrients.
Deep root fertilization is available as a standalone service or as part of our Tree and Shrub Program.
Standalone deep root feeding is a good fit if you have a specific tree showing chlorosis or decline and you want to address the problem directly. A single spring or fall application can make a visible difference, especially for trees with iron chlorosis. You do not need to commit to a full program to get your tree fed.
The Tree and Shrub Program includes two deep root feedings (spring and fall) plus two insect control treatments during the growing season. This is the better option for homeowners who want ongoing protection for all the trees and shrubs on their property. Feeding and insect prevention work together. A well-fed tree resists insect stress better. An insect-free tree uses nutrients more efficiently.
Many homeowners start with a single deep root feeding to see results, then move to the full program the following season. Either approach works. We recommend what makes sense for your trees and budget.
Surface fertilizer has two problems in Davis County. First, alkaline clay soil locks out iron and other nutrients before roots can absorb them. Second, lawn grass in the top few inches intercepts most surface-applied nutrients before they reach tree root depth. Deep root injection bypasses both barriers.
Yes. The pressurized liquid delivers nutrients directly to the feeder root zone where absorption happens. For iron chlorosis specifically, using the right chelated iron formulation is critical. Standard iron from a garden center breaks down in alkaline soil. The chelated iron we inject stays plant-available even at high pH. Most trees show improved leaf color within a few weeks of a spring application.
Trees with iron chlorosis typically show greener, more uniform leaf color within two to four weeks of a spring treatment. Overall canopy density and vigor improve over the course of the season. Trees on the full program show the strongest improvement by the second year as nutrient reserves build.
It depends on how far the decline has progressed. Deep root feeding is most effective as maintenance and early intervention. A tree with mild to moderate chlorosis or nutrient stress responds well. A tree with major structural damage, extensive dieback, or root system failure may be beyond what feeding can fix. Contact us for a free evaluation and we will be honest about what treatment can and cannot do.
For most trees in Davis County’s alkaline soil, twice per year (spring and fall) produces the best results. This is the schedule built into our Tree and Shrub Program. A single annual feeding helps, but the two-application approach builds stronger nutrient reserves over time.
Fruit trees benefit from deep root feeding, but they also need separate insect and disease management. Our Fruit Tree Spraying program covers dormant oil application and targeted pest control specific to fruit-bearing trees. Deep root feeding can be added alongside that program.
We serve Davis County, Utah, including Bountiful, Layton, Kaysville, Farmington, Centerville, Clearfield, Syracuse, Fruit Heights, Woods Cross, West Bountiful, and North Salt Lake.
If your trees show yellow leaves, thin canopy, or declining health, contact us for a free evaluation. We will identify the problem and recommend the right treatment.
Phone: 801-451-2220 Text: 801-893-8836