Native trees and shrubs in Missouri are well-adapted to the local climate — including hot summers and cold winters — and the soil, which can be a mixture of rocks and clay. While native species have developed resilience to withstand the region’s weather patterns and soil conditions, factors such as disease, pests, and activities like clearing fallen leaves and mowing with heavy zero-turn mowers, can all affect the health and hardiness of trees and shrubs.

In addition, the harsh winter’s frozen ground makes it hard for plants and trees to access minerals and nutrients they need to thrive. As spring begins to break and the ground begins to thaw, deep root feeding (DRF) gives the trees and shrubs in your landscape the boost they need to replenish their nutrient reserves and prepare them for the upcoming seasons.

What is Deep Root Feeding?

Deep root feeding is exactly what it sounds like. A high-powered injection system with a probe applies a nourishing blend of liquid fertilizers below the ground’s surface directly into the trees or shrub’s root zone to help promote healthier and more robust growth.

This method has multiple benefits compared to messy granular applications, which distribute nutrients across the soil surface instead of the root zone, or fertilizer spikes you hammer into the ground, which don’t reach the deeper root layers.

Benefits of deep root feeding include:

• Decompaction of tough Missouri soil with aeration: High-pressure injection provides beneficial aeration between a plant’s roots and surrounding soil. Missouri’s rocky, clay soils make it difficult for roots to stretch and grow, so aerifying the root zone stimulates and promotes less stressful root growth, and improves the oxygen supply for enhanced nutrient uptake .
• Making fertilizer available when the tree or shrub is ready: Microenvironments, or small, localized conditions within a larger ecosystem, may make it tricky for some trees and landscape plants to wake up in the spring. Injecting fertilizer right where it will be needed ensures grass, weeds, and other plants don’t grab essential nutrients first and eliminates the risk of nutrients running off like with a surface application.
• Building early disease and pest resistance: Spring is full of potential threats that well-nourished trees and shrubs will be able to resist, making it less vulnerable to stress and damage caused by pests.

Do all Trees and Shrubs Need Feeding?

In short: Yes. Nutrient requirements vary from tree to tree and for plants. Getting enough of the right nutrients independently is tough, and adding fertilizer can provide essential nutrients like nitrogen, phosphorus, potassium (NPK), and micronutrients such as iron and magnesium. These nutrients promote root growth, flowering, and the production of fruit.

Factors influencing the need for fertilizer include:

• Soil Quality: Poor soil lacks the nutrients trees and shrubs need.
• Species: Trees and landscape plants have varying nutrient requirements. Some are heavy feeders and need amended soil, while others are more adaptable.
• Tree and Shrub Age: Young plants, actively growing plants, and those in the flowering or fruiting stage benefit from additional nutrients.
• Environmental Conditions: Soil pH, temperature, and moisture levels can affect nutrient availability.
• Evergreen Trees and Shrubs: Spring fertilization aids in the recovery from winter stress for hard-working evergreen trees and shrubs. They need nutrients like NPK to support the development of new shoots, foliage, and overall vigor.

When to Feed: Spring vs Fall

We often get asked when the best time to fertilize is: spring or fall? The answer is that both seasons are great for fertilizing, each with distinct benefits based on the different growth phases and environmental conditions. Spring is a period of active growth. DRF provides essential nutrients in spring, promoting lush and vibrant foliage as the trees and shrubs develop new blooms and leaves. Spring feeding helps trees and shrubs recover from winter stress and storm damage and prepares them for summer heat and potential pests.

Root growth takes place in the fall, making it a suitable time for DRF. Nutrients support root establishment before winter dormancy and any necessary trimming and pruning. Trees and shrubs store nutrients in their roots for the winter, aiding in early spring growth. Cooler temperatures in the fall reduce stress on trees during fertilizer application.

Understanding the particular needs of the trees and shrubs in your landscape is important. An ISA-certified arborist can assess your trees and will know what they need to thrive.

Let the experts at Craig’s Tree Service help determine if deep root feeding is right for you. Contact us.