First timer. Plan to start a vegetable garden. In your ‘Basic Vegetable garden’ seminar, I was convinced to do a soil testing. Should I do the test using some kit available in hardware store or dig up 300g soil and send it to the Guelph university Lab?
Thank you for contacting Toronto Master Gardeners.
Starting a garden for the first time can be overwhelming. It sounds like you are doing all the right steps to ensure your first try will be productive and rewarding.
There are many different levels to soil testing. Depending on location and concerns, you will need to decide what is right for your situation.
Soil kits available at stores will test pH, Nitrogen (N), Phosphorus (P) and Potassium (K). NPK are the main nutrient building blocks in your soil. The results from this test will give you a good idea of what nutrients are missing to create a balanced soil for vegetable production. Too much Nitrogen will lead to lots of green growth and very little fruit production; Phosphorus is needed to encourage root growth and fruiting; potassium helps with the functioning of the plant. In a proper balance your garden should thrive. The pH of the soil tells you how acidic or alkaline your soil is. If your pH leans too much in either direction it will hinder the growth of the plants.
Soil is complex. For soil to be fertile it needs to not only have the correct pH and nutrients but also aggregates that hold water and air and a host of microorganisms and animal life to create the correct environment for plants to thrive. If you are digging into the ground and do not know the history of your yard there may be contaminants that could transfer to your vegetables. If you are working with raised beds where you have added the soil yourself and know its makeup this is less of a worry
Sending soil off to a facility for testing will give you the NPK and pH of your soil as well as listing micronutrients for you. It can also test for organic content, nematodes, bacteria and fungus as well as lead, pesticides and other contaminants that maybe in your soil.
Depending on the history of your yard and your knowledge of the soil, you will need to decide how in depth you need to be with your testing. Sending off samples will give more detailed results if that is what you need. In either case it is important to closely follow soil collection directions so the results are representative of your garden and not one small section.
Below are a couple of links that may be of use to you.