Should I test my soil?
When deciding on which plants to buy, most people just want those beautiful plants that flower all year round. But, wait! Before you spend all your hard-earned money on plants, there are important things you really need to understand. What are you actually planting them into?
It is integral to plan ahead and keep in mind what soil you have and which plants are best suited to grow in it.
The soil is a large part of what makes your plants grow and testing it is a definite must for growing a beautiful garden. Not as much fun as planting and watching the plants develop but imperative for getting the best results.
So, what is soil testing?
Garden soil can be tested for many things but gardeners usually test the soil’s mineral health and fertility. These tests are inexpensive and the best way to gain the knowledge required to decide how to treat the soil and which plants will flourish in it.
Soil nutrient analysis services (try saying that three times in a row!) come in packages depending on your budget, from basic macronutrient tests to the full-spectrum analysis of the mineral nutrients that plants need. All tests tend to include the PH value and some tests can include cation exchange capacity (CEC), soil texture, particle size, and organic matter.
Unfortunately, nitrogen samples degenerate quickly and are difficult, (but not impossible,) to test for. Nitrogen is also highly mobile in the soil so test results can vary too much to be of any real benefit to a gardener.
Why is soil testing important?
In short, if one of the essential nutrients is lacking in your soil, plant growth will be poor even if all the other nutrients are abundant. And how will you know if your soil is deficient in a nutrient if you don’t test it?
Questions you should be asking
All plants need nutrients to develop properly. Many (if not all) of these nutrients will already be available in the soil in your garden, do you have too much or too little of any of them?
What is the PH of the soil?
How much organic matter is there and do I need to add more?
All of this information will help you to choose the right plants and the best amendments (compost, conditioners, manures, fertilisers, etc.) for your soil’s condition.
And ask yourself this: Why waste money adding products that you don’t actually need?
The answers to the above questions can be found in a soil test.
Soil nutrients for a healthy garden
You do not have to understand nutrients to get a soil test and read the associated advice but here is the technical stuff for those that are interested.
Non-mineral nutrients make up the vast majority of the plant, (96%). These consist of oxygen, hydrogen and carbon. They are available to plants in air and water so the plant just needs good access to air and water through its leaves and roots to obtain adequate supplies of these essential nutrients.
The other 4% are the mineral nutrients, which may seem like a low amount but they are no less important to plant health.
Mineral nutrients are divided into macronutrients (used in larger quantities) and micronutrients (used in only trace amounts).
The macronutrients obtained in mineral form are: Nitrogen, phosphorus, potassium, calcium, magnesium and sulphur.
The micronutrients obtained from the soil are: Boron, chlorine, copper, iron, manganese, zinc, molybdenum and nickel.
Each nutrient has a different degree of mobility in the plant and in the soil and this affects how they should be treated. Excessive nutrient leaching has a negative impact on the environment so adding excessive amounts of nutrients is not just bad for your wallet.
Soil PH and Soil Structure
Soil pH determines if your soil is acidic or alkaline. Most soils are in between, working toward a neutral point. The pH of the soil largely determines which plants will grow best in your garden The soil pH is measured on a scale of 1 to 14 with a measurement of 7.0 considered neutral. A number below 7 is acidic (sometimes called “sour”), and a number above 7 is alkaline (“sweet”). Most plants prefer nearly neutral soil in the range between 6.2 and 7.2 although higher and lower values are common and many plants are quite PH tolerant.
Wide bars indicate higher nutrient availability and narrow bars indicate decreased nutrient availability.
(University of Florida/IFAS Extension, http://blogs.ifas.ufl.edu/marionco/files/2018/04/pH-Chart.png)
Soil structure contributes to drainage and the ground “room” available to the plant to develop a good root system. It also contributes to water retention, which is important for a healthy soil ecosystem, and reduces the need to water the soil, therefore, less wasted water and leaching of nutrients.
Adding good organic matter is generally good for the ‘soil food web’. Some sources suggest that (ideally) organic matter makes up at least 2 to 3 percent of the soil for growing lawns and 4 percent to 6 percent of the soil for growing beds.
When and How Often Should I Test the Soil?
This can depend on a number of individual circumstances but, as a general guide, you can test any time of the year, then take a second test one year later to see if your actions are working. After that every two or three years will suffice.
Where to get a Soil Test
The RHS offer a Soil Analysis Test:
https://www.rhs.org.uk/membership/rhs-gardening-advice/soil-analysis
For a greater choice of tests you can go to Hill Court Farm Laboratories:
The Soil Association can provide more information:
https://www.soilassociation.org/farmers-growers/technicalinformation/improve-your-soil/soil-testing-companies/
Contact us for complete soil testing service and help with your soil test results, soil conditioning and planting needs.
