Every gardener knows that good soil is the key to a successful garden. It’s the foundation of every garden and one that gardeners take great pains to improve each season. Understanding that soil is a living entity, as important as the plants that rise from it, enhances the relationship between gardener and their surrounding dirt.
While some areas of the country have naturally occurring growing soil, other areas need to add amendments to the soil. These are generally compost, humus or fertilizers that enhance the physical property of the soil and provide nutrients for microorganisms or the plants themselves. Looking at the soil’s texture – defined by the percentages of sand, silt or clay – is one component that gardeners can tinker with to improve their garden’s overall health.
Before you get into the more advanced techniques like measuring specific pH and nutrient levels, do a simple inspection by hand. Take a sample of wet soil, roll a piece around with your fingers and see what happens. Does the soil stick together and the particles feel smooth? Does the sample easily fall apart, lacking a binding agent? If the sample is squeezed in the hand does it retain its shape or crumble into pieces? This is a just a quick-check method to understand if the soil is sandy, siltly or has excessive clay. It provides a snapshot that can be further investigated by performing a soil test to determine the type of soil present, as well as the availability of nutrients – or lack thereof.
What Plants Need
Not all plants are created equal. Depending upon which plants a gardener is trying to grow can affect the desired soil conditions. Many factors such as pH, compaction, drainage, and micronutrients may affect how well plants grow in certain soils. As an example, blueberries grow better in soil that is more acidic than what potatoes might like. Understanding a plant’s growing needs will help with soil preparation.
What Soil Provides
As the growing medium for plants well balanced soil will provide moisture, nutrients, and organic matter to support soil organisms such as bacteria, fungi, insects, and other creatures. Another role gardeners shouldn't overlook is that soil is also the support system for your plant roots; this is why . Creating ideal growing conditions is a good preseason activity or one to enhance throughout the growing season.
The physical property of soil based upon percentages of sand, silt or clay, also affects nutrient uptake, ability to hold water, pore spaces for the exchange and movement of water and air, and drainage. Based upon these physical characteristics, soils are defined as coarse-textured, medium-textured, or fine-textured.
Coarse-textured soils are in the sandy loam range, while medium-textured soils would be defined as more silty loams or sandy clay loams. Fine-textured soils, made up finer silty or clay particles are defined as sandy clays, silty loams, or clay. These finer-grained soils tend to have small pore spaces, high water-holding capacity, and abundant nutrients. Coarse-grained soils tend to have large pore spaces, are somewhat nutrient deficient, and have good drainage but don’t hold water as well. Medium-grained soils represent optimal conditions for pore space, nutrient availability, and water movement which in turns leads to good root development.
Another simple test the home gardener can undertake is determining how their soils drain by digging a cubic foot pit and filling it with water. Let the water drain out, then refill the pit and see if the water drains within 24 hours. Good drainage will occur within this period; greater than 24 hours the soil is probably in need of some modification. Several other factors that may play into drainage is if the landscape has relief or topography. Water follows gravity and often the path of least resistance and this can influence the placement of plantings.
Most garden soils will benefit from the addition of compost or mulch. Not only does it provide structure, drainage, and nutrients to the soil, but also enhances the habitat for soil microorganisms that occur there. Leaf litter, manure, compost, and vermicompost are all excellent sources of organic material. These amendments can be added in the fall to allow some of the material to breakdown prior to the growing season. Many gardeners have established compost piles in their yards utilizing their own leaves, grass clippings, manure, etc. to create affordable compost. Obtaining material from neighbors or other sources such as Starbucks which offers its spent coffee grounds for composting are a couple of ways to accumulate more material to be composted.
Take a Soil Test
In addition to understanding the physical properties of soil, the chemical nature of the soil is next. Knowing the soil’s pH which determines if the soil is acidic or alkaline will also contribute to good soil creation. Simple tests are available at nurseries and garden centers, but for a more comprehensive test, consult with your local extension service or a soil testing company. A professional can also help interpret the results of a soil test which can be daunting.
Understanding the chemical make-up of the soil will determine which fertilizers or soil amendments will be necessary to achieve the desired growing substrate. The beauty of a soil test is that multiple samples may be sent in to analyze the composition in different spots of the garden.
Soils are derived mostly from native material, whether it be volcanic ash from ancient eruptions or rich silt from nearby rivers overflowing their banks. This parent material is the foundation of the garden but one that is often disrupted by human activity. Building sites are cleared to soil to construct a house. Land use changes alter the activities that place on a piece of land. Working with this parent material need not be a wrestling match between gardener and garden for many local plants have evolved to survive in current conditions. Whether adding organic compost or using chemical fertilizers, there are many tools in a gardener's toolbox to create good growing conditions. Modifying this foundation may be a simple chore or a major undertaking. But understanding the dirt about dirt may help influence a gardener’s plans and desire to create a thriving, living landscape.