If you’re not getting the results you’d hoped for from all areas of your organic garden, it may be time to do some soil sample testing.
I’ve talked about simple home soil tests before – there really is a lot you can see with your eyes or smell with your nose or feel with your fingers.
But sometimes the only way to get the real goods on your soil’s nutrient profile is to do some soil sample testing and send it to the experts.
In fact, it’s a great idea to get a soil test done by a good soil lab right when you’re beginning a garden, in spring or fall, and then every year or two after that if you can.
And it’s never too late to start.
A lot of people skip this step, and then have to play catch-up later because they made less-than-stellar fertilizing decisions based on guesswork…
Why Soil Sample Testing Is Important
For example, a lot of gardening information recommends using a lot of nitrogen and potassium.
This can cause all kinds of problems. It’s really calcium and phosphorus that more people should be using.
But only a soil sample test really tells you what you need.
On the other hand, many organic gardeners skip the fertilizer and instead focus exclusively on adding organic matter and compost, and never take the time or spend the money to find out if there are specific nutrient imbalances that throw the delicate dance of the soil life off kilter.
It’s really worth the small investment to do some soil sample testing to get some more detailed information before you decide what to feed your soil.
So how do you take a good soil sample? You basically want to get… well, a good sampling of all the soil in your garden…
How To Take Soil Samples For Testing
Most backyard gardeners probably won’t want to pay for separate analyses for each area of their garden, so the best way is to mix soil from several different locations, leaving out any really weird areas that would skew the results.
How to actually get the soil sample for testing? In at least a few different areas, dig a hole and then use a clean shovel to take a vertical slice of soil from the side of the hole, from the surface right down to about 6 inches.
After mixing all the samples together thoroughly in a clean bucket, put 2 cups into a clean container to send to the soil testing lab…
Choosing A Good Soil Lab
I love to use a local soil analysis lab if possible, but good soil labs are not as widespread as you might think.
In spite of the increasing numbers of people doing organic gardening, most of the labs out there still have a chemical mindset when it comes to making fertilizer recommendations.
So it’s important to choose a soil testing lab that uses the right kinds of tests, usually a base saturation test and perhaps some kind of weaker acid test like a Lamotte style test.
We also want a soil lab that’s dancing to the same fiddler as us when it comes to sustainable practices, a lab that focuses on organic.
If your local soil lab happens to fit these criteria, that’s great. But if not, you should probably go a bit farther afield.
Think of it this way. If MI6 needs to know which evil villain is secretly smuggling spent uranium rods out of a military dictatorship in a bid for total world domination, they call on 007, not on the local private eye that Q ran into down at the pub.
The two labs I use most are Crop Services International (CSI – coincidence? hmm…) and International Ag Labs.
A test should cost $50-75, including their recommendations for which fertilizers you need.
You could even pay as little as $20-25 if you learn how to interpret the test yourself. One of my favorite books on analyzing soil test results is The Ideal Soil.
Feel free to ask me your soil testing questions below…