Selecting the Right Tree for Your Soil Spurs Plant Growth, Health and Maintenance

Matching the right tree to the right soil provides numerous benefits. Matching grows strong, healthy trees by delivering nutrients, drainage, and aeration to the plant, boosting disease resistance, and reducing maintenance needs—all while promoting a harmonious, nurturing ecosystem. Plus, it increases your property’s value. A mature, healthy tree adds anywhere from 3 to 15 percent to your home’s value.

But matching the right tree to the right soil is dicey. So, you need to get it right for the best results. Choosing the wrong soil, on the other hand, stunts a tree’s growth, deprives it of essential nutrients, leaves it susceptible to diseases, and even causes death.

Specific challenges to choosing the suitable soil include:

• Diverse soil types and tree needs
• Generating an accurate assessment
• Limited information about specific trees
• Modifying existing soil
• Monitoring to ensure trees continue health

By understanding these challenges and then overcoming them, you can boost your chances of making a successful tree-soil match that nurtures a thriving, healthy tree for years to come. Consulting technicians at the Rhode Island Tree Council can help as well beat the challenges described above.

 Two Critical Steps to Tree-Soil Matching

There are two critical steps to match a tree to the soil. The first is understanding your soil. Start by consulting the USDA’s Plant Hardiness Zone Map, which is divided into 12 zones. Each zone reflects the area’s average minimum temperatures during the winter in that area. Zone 1 is the coldest, while Zone 12 is the warmest. A powerful tool for growers, the map tells you which trees thrive in your climate.

While most of Rhode Island falls within the plant hardiness of Zone 6a, the state’s complete hardiness zone extends from 5b to 7a. This area averages annual minimum temperatures ranging from -10°F to 5°F. The results reflect the state’s coastal location with its northern and western regions being cooler than its southern and eastern areas. Our blog post on the Plant Hardiness map tells you how to use the map to the best advantage.

Test Soil to Determine Key Factors

The second step in the matching process is testing your soil. This step reveals your soil’s pH, nutrient levels, and drainage—all critical factors for tree growth. Home improvement stores, like Home Depot or Lowes, often sell test kits for this purpose so you can test the soil yourself. Or, you can mail soil samples to a professional lab for a more detailed analysis.

The University of Rhode Island’s Soil Testing service, for example, is free through its Master Gardner program. You provide the school’s lab with a sample of your soil. It will test its pH (acidity/alkalinity), evaluate its texture and content, and recommend what actions to take to improve your soil’s pH and health. 

The booklet “Soils of Rhode Island Landscapes” by William R. Wright and Edward Sautter provides more information on Rhode Island soils. The booklet’s goal is to arouse public interest in soils and make people aware of this valuable natural resource.  As the name implies, this 62-page booklet provides an in-depth look at Rhode Island soils.

Research on Tree-Soil Compatibility

Studies by scientists offer valuable insights into the relationship between trees and soil. One five-year study by the Morton Arboretum in Lisle, IL, for example, targets the impact of organic and inorganic fertilizers on soil quality and tree growth. That study shows that soil compost and mulch have a significant impact on soil quality, but the benefits take three years to kick in.

Here are some additional findings tree-soil compatibility research provides:

• Some tree species prefer specific soil characteristics like drainage, pH, nutrient content, and texture. For example, oaks thrive in well-drained sandy soils, while maples prefer slightly acidic soils with good moisture retention.  

• Certain trees have deep root systems that can access water and nutrients from lower soil layers, while others have shallow roots that rely on surface moisture. Matching root systems to suitable soil depths boosts water and nutrient uptake.

• Adding organic matter like compost can improve drainage and nutrient availability in clay soils, but adding sulfur can adjust the pH for more acid-loving trees. But you need to consider these actions’ long-term impacts and cost-effectiveness.
• Rainfall patterns, temperature fluctuations, and local topography can affect soil moisture and nutrient cycling. That, in turn, impacts tree suitability. Matching trees to local conditions and a site’s microclimates boost plant health.  
• Long-term monitoring after planting trees in new soil proves significant. Monitoring growth, survival rates, and potential disease or nutrient deficiencies helps assess the success of the tree-soil match and identify any necessary adjustments.

Understanding these research findings on tree-soil compatibility is beneficial. It helps you make informed planting decisions about what trees to plant in which soil environments. That, in turn, promotes the tree’s health and longevity. Plus, it contributes to healthy ecosystems, among other things. Put simply, making the best tree soil match possible is a win-win for you and the tree you plant.