After just publishing our latest post about soil testing in the garden, I knew I needed to write this one up. Why? Well, in the post on soil testing, I briefly mention home soil test kits and how to use them. And while they’re relatively simple in theory, they can be a bit tricky to use in practice.
Sure, they’re convenient in that you can run to the garden center and pick one up to test your soil the same day. When you go to complete the steps, though, you realize these home test kits have some flaws. So, I sat down to write out my experience with them and the ways I would suggest making their use a bit easier… I hope it saves you some headaches!
Why take my advice on soil test kits?
Honestly, I hated these things the first time I used them. I broke multiple little capsules, spilled the test tubes a couple times, and ended up with results that just weren’t clear. Since then, I’ve figured out my preferred system for using these tests and have a much easier time. I’m not saying I figured out the perfect way to avoid all these hassles, but I have found what works best for me.
Now I routinely use these soil tests as a quick check up on my garden at the beginning of the season as well as during fall cleanup. It’s a great way to get a quick answer as to which beds need the most attention and where to prioritize adding compost. I hope my trial and error can help you avoid some of the same headaches I endured!
What Home Soil Test Kit is This Post About?
The most popular home soil test kit you’ll find at most big box garden centers is the Luster Leaf 1601, pictured below. This is the one I used to write up my review and recommendations. Luster Leaf is the manufacturer, but the kit can be found labeled under several different brand names. The last time I bought one, it was Rapitest, but this time it was under the name Akasha. Either way, if you buy a test kit that looks like this one, it’s likely from Luster Leaf.
How to Use Home Soil Test Kits in Your Garden: Basic Steps
First, Collect a soil sample. Dig 4-6 inches deep in your garden bed and collect a cup of soil, including a bit from all layers within your hole.
How to test soil PH:
- From your soil sample, scoop enough soil out to fill to the first line of the test tube.
- Carefully break apart the PH testing capsule and add it to the test tube.
- Add water to the fourth line and shake vigorously for 30 seconds.
- Let the color develop for about 30 min.
- Compare the resulting color to the chart included in the test kit to determine PH level.
How to test soil Nutrients:
- Take your soil sample and add water to it at a 1:5 ratio of soil to water
- Stir the mixture about 30 seconds then let settle (this can take up to 24 hours for soils with more clay)
- Remove the cap from each remaining 3 test tubes and use the included pipette to fill each tube with water to the fourth line.
- Carefully open each capsule and add it to a test tube, then replace the cap and shake vigorously.
- Let color develop for about 30 minutes, then compare results to the chart included in the test kit instructions.
Tips for Success When Using At-Home Soil Test Kits
Now that you have a general idea of how to use these kits, let me walk you through some challenges you may encounter and how to make the process a bit easier.
Problem: Breaking Capsules
This was my biggest qualm with the home soil test kit when I first tried it. Those capsules are so fragile, and some are really difficult to separate. This combination makes incredibly easy to pinch them too hard while separating the sides and end up breaking the capsule.
To avoid breaking capsules, hold the each side of the capsule very gently between your fingers and start twisting the two sides in opposite directions. Do not try to pull them directly apart. You should only use enough pressure to get the sides to spin, then gradually start twisting them apart, as if you are unscrewing them.
And how does this help? Resistance of the capsule is much greater when the two sides overlap more. If you try to pull them directly apart, you end up pinching on them too hard. Twisting first allows you to grip the capsule gently to avoid breakage.
Problem: Soil not Settling Enough
After you thoroughly mix your soil and water, you may be disappointed by how long it takes for your soil to settle enough to start your testing. The more clay in your soil, the longer it can take. However, keep in mind that it may not need to settle as much as you’d think. Here’s an example using my most recent soil test. This first picture is how the sample looked right after mixing it with water.
…And here’s what it looks like after about 24 hours. It looks like it’s still cloudy and colored, and I thought it might never be clear enough to test.
But, the effect is nearly gone once I transferred the water into the test tubes.
The lesson here? You may not need to wait as long as you think you do, so don’t waste your time waiting for the water to be clear. Instead, when you can see that most of the sediment has settled, go ahead and try filling a tube to see if the water is clear enough. You can always wait longer if need be.
Nitrogen Test Color not Showing Up
This was one problem I had the first time I used these soil test kits, and one I continue to have. In fact, I don’t really have a solution for you on this one! Instead I just have a word of advice: ignore the nitrogen results or just don’t bother testing it at all.
Why? Well, nitrogen is one nutrient that is notorious for making a speedy exit from soil. It dissipates into the air when soil is disturbed (this is part of the reasoning behind no-till gardening methods), and it gets washed away by rain in the garden. As your soil sample sits, most of the nitrogen in the sample is lost. Mine, for example was definitely all gone after I let the sample sit for 24 hours. You can see in my results below that the nitrogen test tube (purple) didn’t show up at all.
The solution? Simply don’t trust the results and know that your garden most likely needs a bit of a nitrogen boost. You don’t have to turn to conventional fertilizers to achieve this, though. In fact you can make your own! Coffee grounds are a wonderful and budget friendly way to add nitrogen to your soil, and so is compost.
My Review: Pros and Cons of Home Soil Test Kits
To sum it up, I’m not impressed by these test kits, but I do think they are convenient for quick answers (once you get the hang of twisting those capsules apart). I mostly agree with this very thorough review over at The New York Time’s Wirecutter column, where they call all the soil test kits they reviewed “complicated, messy, and, often, inaccurate.”
The only part I disagree with is the “complicated” label. At one point in the review they mention that the instructions are not simple or easy to understand. I don’t know if the manufacturer changed their instructions pamphlet, but I find the instructions to be rather clear and concise.
When to Use a DIY Soil Test vs When to Get Professional Soil Testing
I go more in depth to the pros and cons of each of these in our guide to soil testing post. In general, it’s smart to opt for professional soil testing when you’re dealing with persistent probelms in your garden. Starting from scratch with a DIY landscaping project, or creating new flower beds? Anytime you’re planting somewhere you’ve never gardened before is a great time for professional testing so you know exactly what you’re working with.
It’s best to opt for soil test kits when you’re working with garden soil you’re already somewhat confident shouldn’t have any problems. For example, I just used an at home kit when we first built our raised beds because we purchased raised bed soil from a local landscaping supplier.
At Home Soil Test Kits: My Opinion
To sum up my opinion on at-home soil test kits, I think they’re great for routine garden maintenance. I use them to ensure I don’t fertilize unnecessarily and spot nutrient deficiencies before planting. If I ever encounter persistent problems in the garden or start a fresh landscaping project, though, I’ll opt for professional testing. How about you? Let us know in the comments which you prefer and why!
Next, continue your efforts to level up your DIY garden maintenance with our post on sprinkler winterization, and maybe treat yourself to a new “she shed” for all your had work. Or, take a minute to learn about using cover crops in a home garden to further improve your soil’s health!