How To Test Your Garden Soil - Backyard Boss
We are reader supported. External links may earn us a commission.

How To Test Your Garden Soil

When it comes to starting a new garden, it can be very helpful to know what kind of soil you’re starting with. It can inform the rest of your decisions when it comes to soil amendments or what to grow where.

The tutorial below will cover two different soil tests that you can easily do at home. One tests for nutrient deficiencies in your soil, and the best ones require you to send soil samples to a lab. There are home soil test kits as well.

The other test is testing the texture of your soil. More specifically, the ratios of sand, silt, and clay in your soil. This information is useful to understand how your soil will behave about water retention.

It’s a good idea to do both of these tests at the same time. That way, you know right from the beginning what you’re dealing with and what amendments you need to add for the best results.

Testing For Nutrient Deficiencies

Materials Needed

  • Shovel
  • Bucket/jar
  • Measuring cup
  • Sealable plastic bag
  • Soil test (if doing DIY)

Step One: Dig

women digging in soil with shovel
Image credits: HappyNati via Canva

The first thing you need to do is gather some soil to be tested. To do this, choose a spot in your yard and dig a hole about 6-8 inches deep. Keep all the material you removed from the hole in a bucket or something similar.

Where you dig this hole should be somewhat random. Although if you want to test the soil in your raised beds, there’s no point in digging holes in your lawn, so use your discretion.

Step Two: Repeat

Choose another spot at random, and repeat step number one.

Some people choose to mix all the soil into one big bag to be tested. It works, but it’s a lot less precise. Since a bunch of soil from various locations will all be mixed in together, it will be difficult to pinpoint where any deficiencies are.

The alternative is bagging and labeling each hole separately and sending each sample off individually. It is a lot more time-consuming and expensive to do. So the choice is yours.

Step Three: Bag, Dry, And Send

soil in bag for test
Image credits: microgenvia Canva

Once you’ve collected all your samples, it’s time to prepare them for testing. Take about a cupful of soil, and leave it dry out indoors for a few days.

Then bag it up, label it, and send it off to the lab that’s testing your soil for you. If you’re using a DIY test, follow the manufacturer’s instructions.

DIY Test For Soil Texture

The following test won’t tell you much about nutrient deficiencies in your soil. It will, however, give you plenty of information about the ratios of sand, silt, and clay in your soil. You can use this information to decide which plants to plant or amend your soil accordingly.

Materials Needed

  • Straight-sided, clear jar
  • Shovel
  • Dish soap
  • Ruler/measuring tape

Step One: Dig

Dig down about 6 inches and collect enough soil to fill your jar ⅓ to ½ full.

Step Two: Add Water

adding water to soil test
Image credits: microgen via Canva

Fill the rest of your jar with water, leaving about an inch gap at the top.

Step Three: Add A Drop Of Dish Soap

Any old dish soap will work here. This job is to break the surface tension of all the elements in the jar so you get a more accurate reading.

Step Four: Shake

Shake the jar vigorously for a few minutes. Clay particles can stick to themselves, as well as silt and sand, so this vigorous shaking paired with the dish soap should break everything up.

Step Five: Allow To Settle

Place the jar on a flat surface and leave everything to settle.

Some people like to measure the sediment layers at increments of 1 minute, 4 minutes, and 24 hours. I find this unnecessary since the sediment will settle out into its layers and remain that way until disturbed again.

Whichever method you choose, allow the soil to settle for at least 24 hours for the most accurate reading.

Step Six: Measure The Layers

By now, all the soil in the jar should have settled into at least 3 distinct layers. The bottom layer will be the sand in your soil. The second layer is the silt. The top layer is clay. Above the clay will be the water.

By measuring these layers, you’ll be able to determine the ratio of sand, silt, and clay in your soil. This information is super helpful when it comes to maintaining a garden. Sandy soil is well-draining but has poor retention of water.

Silt and clay soil hold onto water for a long time but have poor drainage. The best soil has somewhere in the range of 40% sand, 40% silt, and 20% clay.

Last Word

And there you have it, two super simple soil tests you can carry out to gain a better understanding of the condition, health, and texture of your soil. You can use this information to match these conditions with plants that enjoy these conditions for a beautiful garden. Alternatively, you can also use this information to decide how to amend your soil for optimum health.

It’s important to note that amending your soil with nutrients is a temporary solution. You will have to keep adding these nutrients to your soil as they will get depleted over time. A solution would be to focus on the long-term building of your soil while adding amendments as necessary until you have healthy soil that’s full of life.


You Might Also Like: 128 Backyard Garden Ideas