Good morning, everyone. As promised, today I will share with you where I sent my soil sample to be analyzed and where I’m going to send the test results in order to get a detailed prescription for amending my soil. I’ll also share with you how to take a proper soil sample.
HOW TO GET A PROPER SOIL SAMPLE
In order to get a true analysis of your garden’s soil, you need to test the soil where the bulk of the roots will be – as that’s where the plants will get their nutrients. The average depth of most mature plant roots is six inches, so the soil sample should be made up of soil from six inches down. Be sure the soil is not too wet as that can throw off the analysis. If you think the soil isn’t as dry as you thought when you dig it up, you can let it sit in your bucket for a few hours to dry before mailing your sample.
To get your soil for the sample, use a clean trowel (or other garden tool) and dig a v-shaped hole six inches deep. My trowel has measurement lines on it from the tip up four inches. Two more inches past that are the “shoulders” or top edge of the trowel, so I dig until the entire trowel fits in the hole. The soil at the bottom of the hole is what you want to capture — without catching any soil from the sides or top of the hole that may slide back in. (That’s a challenge!)
How much soil you take depends on how many holes you’ll be digging to make up your soil sample. You will need at least 2 cups of soil for the testing to be done, so keep that in mind while you’re digging. You will need to take soil from various places in your garden, not just one hole. You’ve planted different plants in different areas, and those plants pulled different things from the soil. So, to get an “average” analysis, you will be taking samples from several areas of your garden and mixing them together in a clean bucket.
I have 21 raised beds, so I took two samples from each bed – from the middle area of each bed and on each end. (I often plant two different crops per bed, so I figured it’d be best to take two samples per bed instead of one.) I took just a couple ounces or so from each hole and ended up with this in my bucket.
Dirt for my soil sample
Be sure to mix your soil together well. (I actually took my gloved hands and mixed it together several times.) Then take two cups of the soil and put it into a plastic zipper baggie, labeled according to the instructions from the lab you will be sending it to. It will look like this:
Soil sample ready to mail
WHERE TO GET A DETAILED SOIL TEST
Any agricultural college extension can provide you with a soil test for a small fee. I’ve had a couple of soil tests done by Clemson University. However, the recommendations given weren’t as helpful as I would’ve liked – mostly because the recommendations weren’t for organic amendments. Also, the test didn’t include everything that I’ll be getting on the test I just sent out for.
I sent my soil sample to Logan Labs in Lakeview, Ohio, and paid $25 for their standard soil test. That test includes the following:
- pH
- amount of organic matter in the soil
- total exchange capacity (helps to measure how well the plant can uptake nutrients)
- sulphur
- phosphorous
- calcium
- magnesium
- potassium
- sodium
- boron
- iron
- manganese
- copper
- zinc
- aluminum
- % base saturation Ca, Mg, K, Na
Although there are many labs that will also perform this standard soil test, I chose Logan Labs because the place I will send my results to likes Logan Labs’ results format. If you wish to use Logan Labs, click here for instructions on how to send them a sample. This link also includes a link to instructions on how to take a soil sample, as well as a link for the form to send with the sample.
I shipped my sample (and form and check) to them in a U.S. Post Office small flat-rate box for $5.95. It should take 3-5 days for the analysis once they get my soil, and they’ll send me the results via email.
WHERE TO GET A PRESCRIPTION FOR SOIL IMPROVEMENTS
I bet you never thought of getting a prescription for amending your soil, but isn’t that what it is? When a professional looks at soil test results, he or she can write a prescription for what to do to improve your soil and make it nutrient dense enough to grow healthy plants.
Just adding to the soil what your soil test results tell you the soil is low on is not sufficient. The key is getting your soil nutrients in the right balance. Without that balance, the plant is unable to pull the nutrients from the soil – no matter how much of those nutrients the soil contains. Those nutrients must be bio-available. That’s where I am personally having a problem. This past garden year was terrible, and I know my soil is all out of sorts.
Through a book I’m reading (okay…that I started reading last year then put aside – I’ll get back to it!), I found this website: Soilminerals.org. They recommended using Logan Labs and will review my soil test results and write me a “Soil Fertility Prescription” for organic amendments to heal my soil. If you wish to use them for this service, the cost is $45 via PayPal, and instructions can be found here. You will need to email them your test results, as well as answer several questions about your garden – how long you’ve been growing in the soil, what you plant, etc. (They have a link to sample questions to answer in the email you send.)
If you’d like to use these services, please get your soil sample to them as soon as possible. It really should be done at least 4 months before spring planting, but I got lazy. However, late is better than never. You may want to tell them when spring planting begins in your area (as I will), in case that affects what they recommend.
When I get my test results and my prescription, I will surely share it with you. And let me know (in the comments below) if you have sent for a soil test and who you’re using.
Happy digging.
Sanctuary Gardener 