Healthy soil is the foundation of a thriving tree. Whether you’re planting a new sapling or maintaining an established tree, proper soil care is essential to ensure robust root growth, disease resistance, and overall vitality. In Missouri, where soil conditions can vary greatly depending on location, understanding how to nurture and improve your soil can have a profound impact on the health of your trees. Learn more about how to care for soil to better care for your trees in Missouri, focusing on soil structure, moisture, nutrients, and best practices for maintenance:

Understanding Missouri’s Soil Types

Missouri is home to a wide variety of soil types, influenced by its geographic and climatic conditions. Some common types include:

• Clay Soil: Found in much of Missouri, clay soil has tiny particles that compact easily, leading to poor drainage and reduced oxygen availability to tree roots. While clay soil can hold nutrients, it can also lead to root rot if water doesn’t drain properly.
• Loam Soil: Loamy soil is considered the “ideal” soil for most trees because it balances clay, sand, and silt. It drains well, retains moisture, and provides ample nutrients for healthy growth.
• Sandy Soil: This type of soil has large particles and drains quickly, but it doesn’t hold nutrients well. Trees in sandy soil may require more frequent watering and additional fertilization to thrive.

Before starting tree care, it’s important to know the soil type in your area. Understanding its drainage, nutrient-holding capacity, and structure will help you make informed decisions about soil amendments, watering, and fertilization.

Improve Soil Drainage

Proper drainage is essential for healthy tree growth. Soil that retains too much moisture or stays too dry can stress trees, leading to root rot, stunted growth, or dehydration.

How to Improve Drainage:

• Amend Clay Soil: If you have clay soil, improving drainage can be done by mixing organic matter (like compost or well-rotted manure) into the soil. This loosens the compacted particles and improves water flow. Add about two to three inches of organic matter to the soil surface and work it into the top six to eight inches. You can also add sand, but be cautious, as too much sand can create concrete-like conditions when mixed with clay.
• Aerate the Soil: Over time, soil can become compacted, reducing airflow to the roots. Aerating the soil, especially around the root zone of trees, will allow more oxygen and water to reach the roots. You can use a garden fork or rent an aerator to puncture holes in the soil. This is especially useful in heavy clay soils or areas with heavy foot traffic.
• Mulching: Apply a two to three inch layer of organic mulch around the base of the tree. Mulch helps retain moisture, regulates temperature, and improves soil structure as it decomposes. However, make sure the mulch doesn’t touch the trunk, as this can cause rot.

Maintain Soil Fertility

Soil fertility is crucial for the long-term health of your trees. Trees require a variety of nutrients, including nitrogen, phosphorus, potassium, calcium, and magnesium, to grow and resist disease. While Missouri’s soil can often provide these nutrients naturally, adding organic matter and using fertilizers may be necessary to replenish depleted soil. Consider the steps below to improve soil fertility:

Adding Compost and/or Organic Matter to Your Soil: Adding compost or well-rotted manure is one of the best ways to enrich the soil. Organic matter improves soil structure, water retention, and nutrient-holding capacity. Spread a layer of compost around the base of the tree and work it into the top three to four inches of soil.

• Soil Testing: Before adding fertilizers, consult with a certified arborist who can test your soil, which will provide detailed information about your soil’s pH, nutrient levels, and any deficiencies. This helps you avoid over-fertilizing or using unnecessary chemicals.
• Fertilization: If a soil test indicates that your soil is deficient in specific nutrients, you may need to use a balanced, slow-release fertilizer. Choose one that is appropriate for the tree species you’re caring for. Generally, fertilizing in the spring is best, just as the tree begins to grow, so nutrients are available during the growing season.
• Avoid Over-Fertilizing: Too much fertilizer can harm trees by promoting excessive, weak growth that is more susceptible to pests and diseases. Stick to the recommendations on the fertilizer label and always err on the side of caution.

Regulate Soil pH

Soil pH affects the availability of nutrients to your tree. If the soil is too acidic or too alkaline, trees may not be able to absorb the nutrients they need to thrive. Many trees in Missouri, like oaks, maples, and pines, prefer slightly acidic soil, but the ideal pH depends on the species. Again, consulting with a certified arborist will eliminate any doubts about your soil’s nutritional value.

How to Adjust Soil pH:

• To Raise pH (Increase Alkalinity): If your soil is too acidic, you can raise its pH by adding lime. This is particularly common in Missouri’s acidic soils. Lime should be applied in the fall or early spring. Be sure to follow the recommendations from your soil test for proper application rates.
• To Lower pH (Increase Acidity): If the soil is too alkaline, you can add sulfur, pine needles, or composted leaves. These organic materials will slowly lower the pH over time. Again, a soil test will guide you on how much material to add.

Watering Trees the Right Way

Water is one of the most critical factors for tree health, but over-watering or under-watering can cause significant stress. The goal is to ensure the soil remains consistently moist without becoming waterlogged. Trees need deep watering, especially in the hot, dry summers in Missouri.

How to Water Trees Effectively:

• Deep Watering: Water deeply at the base of the tree, ensuring that moisture reaches the root zone. This encourages roots to grow deep into the soil, where they are better able to access water and nutrients.
• Use Soaker Hoses or Drip Irrigation: To prevent soil erosion and ensure even watering, consider using soaker hoses or a drip irrigation system. This is particularly important for newly planted trees or trees in areas with sandy or clay-heavy soil.
• Watering Frequency: New trees and saplings require more frequent watering until their root systems are established. Once a tree is established, it generally requires less frequent watering, but during drought conditions, you should continue watering regularly.

Avoid Soil Compaction Around the Root Zone

Soil compaction is one of the biggest threats to tree health. Heavy foot traffic, construction, or even lawnmowers can compact the soil around the root zone, making it harder for trees to absorb water and nutrients.

How to Prevent Soil Compaction:

• Create Mulch Beds: As mentioned, applying a layer of mulch can protect the soil and tree roots from compaction.
• Use Protective Barriers: If you’re working in the area around a tree or need to prevent foot traffic, use physical barriers or boards to avoid compacting the soil.

Need Help with Your Tree Care? Call us Today!

Your lawn, trees and landscaping all depend on healthy, nutrient-rich soil. Good soil equals good plant life. It’s that simple.

Our certified arborists and plant care specialists are experts in guiding homeowners through the process of caring for your trees, shrubs and ornamental plants for your landscaping. They can assess the health of your trees, make recommendations regarding their care, improving soil and can identify hazards posed by trees or limbs, and if necessary, take them down and eliminate any potential problems.

Contact us today! We’re here to help!