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.

Click for video transcription

Phil: Hey guys it’s Phil from smilinggardener.com, if you haven’t checked out my free online organic gardening course, you can do that right on the home page of smilinggardener.com.

Today we are moving onto soil sample testing through a soil lab. This is a step that most people don’t do that is so important if you want to grow really healthy nutrient dense mineralized food or if you want to have all your plants be free of pests and ever have to spray anything ever again. This is a very important step to doing that and here is why it’s important. What most gardeners will do is they will get, they will use a lot of composed if they are specially, if they are organic gardeners, get a lot of composed on there. It certainly does have some nutrients and if it’s a good composed and then they will also use some fertilizers, especially NPK fertilizers, nitrogen-phosphorus-potassium or maybe some kind of more of a broad spectrum fertilizer but really when you are doing that you are guessing as to what your soil needs and the chances are extremely good that you are putting some minerals on there, your soil already has too much of and that maybe you are not adding certain minerals that your soil really needs.

So, it’s just like in the human body, we need to get a certain balance of all the minerals in the soil in order to have healthy food and in order that’s the two main things I always think of, healthy food pest free plants. So here is how I take a sample, first I clear off any organic debris any mulch and then I want to take a sample starting at the surface and going down 6 or 7 inches.

So, I do that with a very clean shovel, I don’t want to have a rusty shovel just like I don’t want to have a rusty pale that I put this in because that will influence the soil results. So I go down in there and you are sometimes what I do mix a little easier is I will pick that first shovel and kind of throw it aside, in that way it makes it much easier to take just a slice because I really want to get the full depth of soil down to 6 or so inches, then when I have that I put it into my very clean pale and that pale didn’t have any fertilizer or salt of anything in it because that would also affect the results.

One really important part of this year is to take samples from a few different spots in your garden. If you have a really weird spot in your garden you would I either leave that out or test it separately but for all your garden parts, parts of your garden that are the same, take a few samples and mix them together, that way you are going to get a more representative sample of your garden. Mix them together in here, they you just take a couple of cups put it into a zip lock bag, send that off to the lab.

When it comes to soil labs, you can go with your local lab and may even have some local knowledge but what I found is that there are almost always chemically minded, they are coming at soil from a very conventional way which is very different than organic.

So what I do is I ship soil sample to an organic lab, the two I often recommend are crop services international and international egg labs but there are a lot more. It’s a little harder you know in the US you can find a lot. It can be a little more difficult in other parts of the world including Canada to find a good lab but if you can find them where they are giving organic results that’s wonderful. I have a little bit written, more written in the article below about some other things I look forward in a lab so you can read that help you find a really good lab.

If you have any questions or doubt about soil testing, you can ask them down below and I will answer them. If you are on my website and you haven’t subscribed to my free online course here you can do that down below. If you are on Facebook, you can click the like button that is of course if you like and if you are on YouTube you can subscribe up above and I will see you next time.

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

Soil Sample Testing

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

Soil Sample Testing

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…


  1. Gare on April 13, 2013 at 10:26 pm

    Hello… We just started a homestead in se Asia and the soil is 80-90% clay, 2 questions for You Phil 1) what’s Your recommendation of where We start? and 2) is it better to have some truck loads of the best black soil, We can find, dumped on top the clay or amend it?… We Very much enjoy following Your gardening exploits All over the world 🙂

    • Phil on April 17, 2013 at 11:22 am

      Can you dig in the soil right now? If so, it’s probably best to work with it. A soil test would be a good starting point and it could help you decide – you can probably send a sample to Australia if you can’t find a good lab in your area. After that you’ll probably want to start making or acquiring compost and other organic matter if your soil is low in that. My preference is to work with the existing soil if possible rather than bringing in topsoil that can raise the grade too much and can cause drainage issues when dumped on top of the clay.

  2. melissa manton on April 14, 2013 at 12:12 am

    Hi Phil. Do I need to get my soil tested if I live on the coast in primary and secondary sand dunes and it’s sand, sand, sand to kingdom come. Thank you. Melissa

    • Phil on April 17, 2013 at 11:18 am

      Are you trying to grow right on a beach-like soil? If so, I would amend it first with compost and let that settle in for a few months and then get it tested. Otherwise, if you have something that more resembles sandy soil, like it already supports plant life, you can test now.

  3. MLF on April 27, 2013 at 12:37 pm

    What is the maximum % OM one should target for a growing medium/soil?

    • Phil on May 2, 2013 at 11:01 am

      In the soil, 5-10% is usually about right. In a potting mix, I’ve successfully used as high as 50%, but my usual recipe uses 1/3 compost.

      • MLF on May 2, 2013 at 5:10 pm

        Thank you. CSI rated my ‘soil’ at 26% humus, CEC = 29; ERGS at 1200; ph 7.3 and base ratio’s not too far off although K was 13% (and they called the base ‘excessive’) therefore I assume the micro-life is alive and well (also feeding with 1oz/2 gallons H2O molasses every 2 weeks). The LaMotte ratios were all well in the target ranges except Mg which was 100; both nitrogens were good. I’d appreciate your comments (if you have time, otherwise I understand) and would also like to know what you recommend to move the Mg up (epsom salts [S on the base test was 100]) or do I just let it alone? The plants are tomatoes and eggplant and they look great, are flowering well and filling fruit – EC has been about 600 recently (distilled water). Thank you for all you are doing – it’s very helpful and fun. It’s also lead me to the BioNutrient Association and some recent communication with Dan Kittridge. All of this resonates very well with me as I believe we are here to humbly reedem that which we come to understand is broken. FYI I’m in Austin, Tx

        • Phil on May 6, 2013 at 1:25 pm

          I reserve detailed soil analysis for Academy members, but briefly, I think epsom salts would be a good bet, and maybe some calcitic lime (for Ca and Mg) to help knock down the K. Glad you’re enjoying the site here. Wow I’ve never seen humus that high!

          • MLF on May 6, 2013 at 7:06 pm

            Thank you.FYI, I am an Academy member (sent the pic of the cattle fencing compost pile recently).Regarding the humus number, I’m using about 35% compost and amending with lignite . . . I suppose that explains it.

  4. Brenda on April 27, 2013 at 1:39 pm

    If the soil is needing serious help, would it be easier to build some raised beds as in Mel Bartholemew’s book “The Square Foot Gardening” to just use what he calls a perfect mix of 1/3 of each of sphagnum peat moss, vermiculite, and a good mix of compost rather than try to amend your soil that could take years to get it to where you want it, especially if you want to raise some food now?

    • Phil on May 2, 2013 at 11:07 am

      In my view, his mix isn’t ideal if you want to sustainably grow very nutrient-dense food, but yes, raised beds can be a good way to go if your soil is so compacted you can hardly dig in it. I prefer to stick with half compost and half topsoil in my raised beds.

  5. Chris Campagnaro on May 26, 2013 at 2:32 am

    So, what are the best lab options in Canada for ‘Base Saturation’ & ‘Reams’ testing, … and, do you recommend both tests in conjunction, or just one or the other? Does the Soil Food Web lab in Alberta do these tests?Cheers ; )Chris

    • Phil on May 27, 2013 at 2:45 pm

      It’s hard to find in Canada. I’ve had a base saturation test done at A&L Labs, which I was happy with as long as I didn’t rely on their recommendations. I can’t find any Reams testing in Canada. I rely more on base saturation if I’m interpreting the results myself, but I will do a Reams test at the same time if I’m sending it to a lab that gives good recommendations, such as Crop Services International. I’m not sure what Soil Food Web does.

      • Chris Campagnaro on June 3, 2013 at 4:14 am

        Thx for that Phil, I’m going with CSI.

      • Chris Campagnaro on June 3, 2013 at 5:32 pm

        BTW, for general information purposes, Bob at Soil Food Web Canada in Alberta advises me that they do normally conduct ‘Reams’ type soil testing, however, he added that they are presently without a lab tech. They are recruiting, but until further notice they can not do any testing.

        • Phil on June 5, 2013 at 11:16 am

          Interesting, I was under the impression they didn’t do Reams testing. Good to know.

  6. Juliet on August 14, 2013 at 9:25 pm

    Phil, I am on the third lesson and absolutely love all this wonderful information. We live in the Panhandle of Florida and this is my first gardening experience. We have three raised beds, 18 inches high. My husband did such a good job building them. We brought in 2 truck loads of mushroom compost and mixed it with a sandy loam. I had one bed of tomatoes since Spring and fought lots of worms and didn’t do very well…though we have had constant ran this Summer. I have pulled those up and planted three new tomato plants in a different bed. I just spent a lot of time picking worms off of these plants. I sprayed them with neem oil with added garlic and cayenne pepper. Since I planted these I saw your information on MyCorrhize fungi and have ordered that. I haven’t seen you mention mushroom compost and would like to know your thoughts on it. Certainly I need to have the soil tested. I did well with zucchini, squash and my eggplants are still producing. We have a large ground bed that I planted about 45 male 2-year asparagus plants and they are still producing. My second question to you is when I receive the fungi what is the best method to quickly get some to the roots of my tomato plants? I really want some organic tomatoes! I was thinking maybe rake some of the soil away and poke holes in the soil to add it and then cover them back up. Should I mix the fungi in water and try and water it down in there? Now when I am at the garden and see bugs all I think of is my plants are not healthy. Thanks! Julie Grossman

    • Phil on August 18, 2013 at 1:33 pm

      I’m not a big fan of mushroom compost because it can have some pretty major pesticide residues, and the mushrooms already took a lot of the nutrition, but if you work on improving the soil biology through microbial inoculants, they should gradually take care of the pesticides. And of course you can improve the nutrition over the years. If the mycorrhizal fungi you get is a powder, you can mix with water and water it into your soil. Otherwise you can dig holes near the tomatoes and drop some in. I can’t get into much detail on your tomatoes here – obviously they aren’t optimally healthy, but building healthy soil takes time. It should get better each year.

  7. Jason LaMarche-Hunderup on April 10, 2014 at 3:37 pm

    I live in King, Ontario. Where do you recommend getting my soil tested from an organic perspective? I know University of Guelph does testing, but I don’t know if it’s in line with your recommendations. Thanks, as always.

    • haleynauta on April 10, 2014 at 8:46 pm

      Hi Jason, Phil’s out of the office for a while so I’m responding on his behalf. Even if you live in Ontario he usually recommends shipping to either Crop Services International or International Ag Labs. If you don’t want to ship to the US for samples (you would have to fill out some extra customs stuff) you can easily work with http://www.alcanada.com/ although he still prefer the former 2 for their organic focus. AL is in London, Ontario though – so it might be just as easy for you as UoG would be.

  8. mervyn on April 15, 2015 at 4:36 pm

    do you recommend using rock dust

  9. Julie on April 15, 2015 at 5:41 pm

    What I have learned is the soil test is the easiest part of the process. It’s the interpretation, analysis and then execution of how to go about remedying/amending the results of your test to get the desired result that’s the hard part. This is when I feel like I need a degree in soil science because every amendment you add (or don’t add) can affect other nutrients/components of the soil. I’ve received so much conflicting advice that I’m afraid to do anything! Do you offer soil test analysis?

    • Phil on April 15, 2015 at 10:33 pm

      I agree, it can be a huge challenge interpreting soil tests, and then finding the appropriate fertilizers. Unfortunately, it takes so much time to do it right that I have to reserve doing this for my Academy members only ( https://www.smilinggardener.com/academy/ ).

  10. Sarah Lee on April 15, 2015 at 6:15 pm

    I just wanted to plug my soil testing lab in Arcata, CA. We do testing for soil, plant tissue, and water. The recommendations we make are ONLY for sustainable organic farming practices. We also have a consulting arm to the business to help people make the transition from conventional to organic farming. Check out our website at http://www.dirtybusinessdivas.com

  11. Di on April 16, 2015 at 12:51 am

    We have some moss growing in our garden bed after the soil was turned. Is this normal for the time of year in southern Ontario, or a sign something is off in the soil. Do you know of a good lab here? Thanks

    • Phil on April 18, 2015 at 5:06 pm

      Hi Di, moss is normal. It’s just a type of plant. It’s true that it sometimes grows in shady, acidic soils, as most people think, but it can also grow in sunny, alkaline places, as there are many kinds of mosses. Personally, I would let it grow – it’s entirely fine. A&L Labs is okay if you learn how to interpret their base saturation test organically, but I don’t know of any good, organic labs in Canada.

  12. Keith Taylor on April 16, 2015 at 3:56 pm

    Wow, Phil, I’ve been growing my own food for years and never once have I had my soil tested. I use the weeds, grass clippings, leaves from the trees and water from the duck pond as fertilisers, adding all the ash from our nightly winter wood fires, which I sprinkle on top of the decaying vegetable matter that was left over from the mulch on the beds. This is supplemented by our coffee grounds (we drink a lot of coffee) and my own urine, which I dilute to 10:1 before using it on the beds. In spring I let the weeds come up and plant my seeds among them, using them to protect my plants from wind, frost and pests as the insects prefer their natural food to my “artificial” plants. When the plants are robust enough to support themselves, I start weeding, pulling the weeds up gently to help aerate the soil and generally dropping them on the beds from which I’ve pulled them up, so that they can break down and return the nutrients they’ve used to the soil. The surplus go to the compost heap. My veg gardens always manage to look like jungles, with food everywhere … except this year, because my niece is one of those crazy cat ladies and her cats have now decided that my veg garden is a great toilet area, so I’ll not be planting any more from now on.

  13. Dee on May 27, 2016 at 12:17 am

    Could you explain how to interpret the test yourself? You do mean to still send test to lab, but just not have them give results on what your soil is lacking, right?Thank you!

    • Phil on May 28, 2016 at 3:23 pm

      Interpretation is a complex process – you can learn how to do it, but it’s not something I can explain in one article. But what I encourage most people to do is get the lab to interpret it for you and make recommendations. That’s why an organically-minded lab is important, so you can get organic recommendations.

  14. Guest Connie on May 31, 2016 at 2:05 pm

    Hi Phil, I’m a beginner at your website and am excited already. Just a funny note – I listened to the soil test video first and wrote down “International Egg Labs” as one of the recommended soil testers…which doesn’t bring up anything useful online! Glad I continued to read…:-)

  15. Kimberly Williams on February 5, 2021 at 10:21 am

    Hi Phil, Just discovered this website when searching for appropriate soil testing lab. I have almost an acre that has been watered with well water that is heavy in boron and sodium. I have been making compost from the cut grass and fallen leaves from this property. I now want to see how much boron and sodium is in the ground and in my compost so I can “start fresh” if necessary. I believe the boron is responsible for many of my plants dying. Do you know whether the labs you named would be appropriate for that type of testing? I have been told boron builds up in the soil and never leaves. Do I need to dispose of my compost and start over? Until I learned of the problem, I have been watering it with the same contaminated well water. Thank you so much for your advice.

    • Phil on February 8, 2021 at 10:57 am

      Yes, these labs will both test for boron and sodium. Whoever you go with, let them know about your situation and ask them what advice they have. Boron can be leached out with irrigation, which works better when the soil is otherwise balanced, and your soil test will help you with that balancing, too. I probably wouldn’t dispose of the compost but if it tests high for boron and the soil, too, you may keep it for a few years until your soil boron is back down.

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