Soil Health & the Role of Garden Maintenance

Soil health, the quality and composition of your soil, is a key factor in how well your garden and landscaping perform. We’ve previously discussed the characteristics that go into a healthy soil and the corresponding affect on plant vitality. Now, let’s talk about some of the ways a comprehensive garden management and landscape maintenance program can improve the quality and health of your soil.

Garden Maintenance Practices That Optimize Soil Health

In the northern Virginia region, clay dominates the soil. Clay’s ability to hold water and nutrients makes it a useful part of the soil, but too much clay can prevent adequate drainage and airflow. Thus, we always add leaf compost mixed with topsoil and composted manure (i.e., decomposed branches, leaves, critters) to optimize soil health when we plant. At newly constructed homes, we often find the top six inches of soil has scraped off during construction, so we may have to add the topsoil back if the builder did not replace it.

Let’s talk about some specific improvement and maintenance techniques that are employed to support soil health for garden beds and trees:

1. Mulching. Adding mulch boosts the nutrientlevels in the soil. The mulch decomposes and becomes topsoil over time.
2. Adjusting pH. If the pH is too high (alkaline), we add sulfur to lower it. If it’s too low (acidic), we add lime to raise it. In Pennsylvania, soil tends to be alkaline because of an abundance of limestone; in Virginia, our soils tend to be naturally acidic. We correct the pH balance during maintenance to encourage optimal nutrient absorption.
3. Topdressing. Adding a layer of compost also improves soil health by boosting the nutrient levels.
4. Soil amendments. Anything that is organic (i.e., comes from living things that die and start to decompose) can be beneficial to the soil. Worm castings can be quite helpful as a soil amendment.
5. Aerating turf. Aerating creates much-needed air pockets in soil that has become compacted. We aerate because plants use oxygen (O2) to support growth but primarily use carbon dioxide (CO2) to make food. Plants use CO2 to create energy and use O2 when they burn the energy they have created (i.e, when they are actively growing or producing fruit).
6. Vertical aeration. Vertical aeration is the process of blowing air into the soil around tree roots. If soil health is in extremely poor around trees, we use pressurized air to loosen the soil and remove it from around the roots. Then we add back good soil around the exposed roots.
7. Vertical mulching. We use an auger tool to drop compost into holes created during aeration—an added boost to soil nutrients.

Measuring How Soil Composition Interacts with Plant Life

Plants thrive in a healthy soil that is consistent with their needs. The soil provides stability for the roots so the plant can support itself, holds the right amount of water, and provides nutrients for plants to produce their own food, which in turn gives them the energy to grow. A lively garden above ground is the direct result of lively soil composition below ground.

Soil Nutrients

The two types of nutrients we measure to determine soil health are macronutrients and micronutrients. Plants need fairly large quantities of macronutrients (which include nitrogen, phosphorus, and potassium), while they only need small amounts of micronutrients such as iron, magnesium, calcium, copper, zinc, and manganese. Some of these nutrients occur naturally in the soil, while others are added to the soil by organic material. (As living organisms break down, they release many of these elements.)

Some nutrients are leached away with water drainage and must be added back into the soil periodically, typically through fertilizer. This is especially true of nitrogen in lawns because any nitrogen that the lawn doesn’t immediately absorb is leached away. A good landscape maintenance company will pay close attention to how much fertilizer it applies, making sure to maximize the benefits to plants and turf while avoiding over-saturation of nutrients.

Soil Testing for Nutrients and pH Values

One of the key ways a good landscape maintenance specialist will ensure soil health is through soil testing—sending test samples of the soil to a lab to check nutrient levels. The soil test will reveal if there is too much or too little of a particular nutrient.

It will also show pH values, which is important because there may be adequate nutrients in the soil, but if the pH is off, the plant may not be able to absorb those nutrients correctly. From the soil test, the landscape professional will know what sort of soil amendments to add (e.g., worm castings, compost, fertilizer—or in the case of a pH imbalance, lime, or sulfur)—to return the soil to optimum readings.

For the overall health of your garden and lawn, it is important to periodically take soil samples and test to determine if the soil is in good condition. Is it holding moisture properly? Is it draining appropriately? Does it have a good balance of nutrients and organic matter? Is it pH-balanced?

Hiring a reputable garden management company is one of the best ways to make sure your garden and lawn are growing in the best soil conditions possible.

Perhaps you are wondering how to bring out the fullest expression in your landscape and gardens. Our eBook: Choosing the Right Kind of Landscape Maintenance Firm, is full of valuable information to help you understand the fundamental differences between landscape maintenance companies.