According to the Tree Care Industry Magazine, non-living causes of plant decline, including soil problems, account for 30 to 40 percent of issues encountered by an arborist. For Nebraskan homeowners, this includes areas of the state with clay soils, like Omaha and Lincoln.
Understanding Nebraska's Clay Soils
Clay soils are heavy, dense, and composed of incredibly fine particles. Because of their structure, clay soils are great at retaining moisture and nutrients, but this also results in poor drainage and aeration.
Nebraska is significantly composed of clay soil, especially in its central and eastern regions. Eastern Nebraska also has alkaline pH levels, thanks to glacial till deposits. These factors make tree care significantly different from areas with loamy or sandy soils.
How Clay Soils Harm Trees
Because of their structure, clay soils can hinder tree growth. Here are the reasons why:
- Soil Compaction – Clay soils are susceptible to compaction from foot traffic, construction, or heavy equipment, especially when wet. Compaction reduces pore space, which limits oxygen and water movement to roots. This results in shallow rooting, slow growth, and early leaf drop. Most homes constructed after World War II will have compacted soil.
- Poor Drainage & Waterlogged Roots – Clay’s tight soil structure means water drains slowly, sometimes leaving tree roots saturated for extended periods of time after rain. This deprives roots of oxygen and creates the conditions for root rot. A drainage test can help determine if your soil has poor drainage.
- Iron Chlorosis & Alkaline pH – Eastern Nebraska’s alkaline soils withhold iron and manganese, making them unavailable to tree roots even if they’re present in the soil. This is one of the most common soil issues in the area, and results in yellowing leaves, especially in pin oak, river birch, and other pH-sensitive trees.
Signs Your Tree Is Struggling With Soil Problems
Many symptoms that arise from soil issues can resemble pest or disease damage. Having an accurate diagnosis matters. If you notice these symptoms, contact your local arborist to get a proper diagnosis:
- Yellowing or off-color leaves with the veins remaining green
- Stunted or slow growth
- Standing water after rain
- Heaving or cracking soil near the tree’s base
- Early leaf drop
- General dieback
How to Improve Clay Soil for Trees
Guessing soil issues can become costly and make things worse. A professional soil test identifies pH, nutrient deficiencies, and compaction issues before treatment. The Davey Institute Diagnostic Lab is a USDA-APHIS-inspected facility that analyzes soil samples for fertility, water quality, and abiotic disorders, then provides tailored management recommendations.
Once soil testing is completed, here are a few actions that can help with clay soils:
- Air Spading & Soil Aeration – Air spading uses compressed air to fracture compacted soil without excessively damaging roots. It can also be used to punch through compacted layers to create a drain. It’s one of the most effective tools for restoring healthy root zones, but it should only be done by a professional. “For trees in Nebraska, soil aeration is great for clay soils that can be easily compacted. After aeration, clay soils will see improved drainage, which results in improved tree and root health,” says Dr. AD Ali with the Davey Institute.
- Organic Matter & Mulching – Mulch moderates soil temperatures, retains moisture, and slowly adds organic matter as it breaks down. Spread 2 to 3 inches of organic mulch around a tree, keeping away from the trunk.
- Soil Amendment & Fertilization – Amendments and fertilizers can help increase soil nutrient levels. Slow-release fertilizers provide sustained nutrient availability over a longer period, while targeted amendments, such as elemental sulfur to lower pH and iron chelates to address chlorosis, help balance soils.
- Choosing the Right Tree Species for Nebraska's Clay – Not every tree species thrives in clay soils. Bur oak, Kentucky coffee trees, swamp white oaks, and hackberry trees do well in Nebraska’s clay soils, while red oaks and river birches are more likely to struggle. “Tree species with shallow root systems may be able to tolerate clay soil’s heavy moisture and compact nature,” says Dr. AD Ali with the Davey Institute.
Davey SoilCare®: Science-Backed Soil Solutions for Nebraska Trees
Davey SoilCare is a holistic, sustainable approach to help restore tree health. Our experts understand that each property is unique and requires different solutions to correct soil problems. Some examples of SoilCare solutions include:
- Enhancing soil chemistry with our slow-release fertilizers, which are proven to address mineral deficiencies
- Using amendment materials to improve soil quality when biological issues are present
- Using air tools to address physical issues such as soil compaction
Davey’s experts in the Omaha area can help determine the best course of action for your soil.
FAQs: Nebraska Clay Soils and Tree Care
A professional arborist inspection, as well as a professional soil test, can help determine if your tree is struggling with soil issues and not a pest or disease infestation.
It can be difficult to fix clay soils on your own; a professional has the expertise needed to pinpoint issues and provide more options that may help make the soil more hospitable to your trees.
Trees like bur oak, Kentucky coffee trees, swamp white oaks, and hackberry trees do well in Nebraska’s clay soils.
Soil should be tested every 3 to 5 years for residential properties, unless you suspect an issue with your soil. Davey’s diagnostic services test plant, soil, and water samples for insect, disease, and weed pests, soil fertility, water quality, and abiotic disorders caused by environmental stress.
