Spring Tip: Checking the Health of Your Garden Soil

It’s an exciting day -- your seedlings are thriving and ready to be transplanted. Your plants might be ready, but what about your soil?

In this article, we cover some basic ways to measure your soil’s composition, pH and nutrient levels.

So, what are some ways to check your garden soil?

Method 1.) Send a soil sample to a professional lab for testing.

For serious gardeners with large plots, you could opt to send small bags of soil into a lab that offers soil analyses to the public at affordable rates.

These labs have equipment and technology the average gardener does not have and are well worth the small fee they charge per sample. 

In addition to finding the nutrient levels of nitrogen, phosphorus, potassium, and other micronutrients, labs will check the soil’s pH, organic matter volume, salinity, and levels of toxic metals like lead and aluminum.

While the tests ran by labs are comprehensive, there are simpler ways for the average home gardener to do basic soil check-ups.

Method 2.) Buy an at-home soil test kit.

Another option is using a simple soil test kit that analyzes soil pH, nitrogen, phosphorus and potassium levels. These test kits can be purchased online or from a local garden center and will give you a very general picture of the nutrient levels in your soil.

A soil test kit is an invaluable tool for gardeners; they're inexpensive, reusable, easy to use and will aid you greatly in assessing the general health and viability of your soil.

Method 3.) Do a visual/tactile inspection of your soil.

Start inspecting your garden soil by looking at how it breaks up when you work it in your hand. Try wetting it with a hose to see how readily it takes up the water.

Does the soil clump up like clay? Or does it slip through your fingers like sand?

Whether you have clay-like or sandy soil, most gardeners find they can get away with simply amending the soil with organic matter such as compost.

For clay-like soils, consider adding organic matter to your garden to improve soil composition. In clay soil, compost, worms, and leaf mulch aerate the soil and lessen compaction, allowing for better drainage and healthier root systems.

For sand-like soils, adding organic matter can improve its framework. Organic matter increases the soil’s water retention by absorbing and holding onto water that would otherwise run through the soil before root systems get the chance to absorb it.

Very rarely are gardeners fortunate enough to pick a plot and find its soil is already perfect.

More often than not, your soil will need amending to improve its overall constitution and structure.

Adding organic material such as compost or high-grade organic top soil can help develop better structure for both types of soils.

Organic Matter: To Add or Not to Add?

Compost is a readily available source of organic matter with which to amend your garden, and it is easy to find bagged at a local garden center. If you can prepare it yourself, that is always best. Making your own compost is great for your garden, your wallet, and the environment.

When adding organic matter — whether it is compost or not — don’t be afraid to make use of what you already have at home; an old bag of potting soil, leaf mulch left over from fall, grass clippings, and any vegetable scraps can be used to improve soil.

If you decide to add vegetable scraps to your garden, we recommend not adding food scraps directly in your soil plot, but rather compost them before adding them into your soil. This will reduce the likelihood of critters digging up your garden! But if critters aren’t a problem for you, then adding compost-friendly material is fine.

Amending Soil pH

If your garden soil has an issue with pH, soil amendments are a great way to address it.

If your soil is below 6.2, you may want to raise its pH.

Liming agents like agricultural lime and oyster-shell lime can be purchased and used to amend low pH soils. Even a few household items like eggshells, wood ash, and baking soda are known to be used by gardeners looking to offset acidic soil.

If your soil is more akaline, that is more than around 7.2 pH, then you’ll need to amend it with something acidic. Sphagnum peat is a great organic method to lower a soil’s pH since its pH is generally around 4. Coffee grounds also work great. If you have neither, you can pick up a bag of low pH garden soil from a local garden center to help you adjust your soil’s pH.

Though having neutral pH soil is usually best, it is important to note though that not all plants will thrive in a neutral pH environment. Blueberry bushes, rhododendrons and hydrangeas actually enjoy acidic soil!

Garden Nutrients: Nitrogen, Phosphorus and Potassium

Garden soil is made up of numerous mineral nutrients, but nitrogen, phosphorus and potassium are the most crucial for healthy plant growth. Like soil composition and pH, imbalances of these three important nutrients can easily be addressed when amending the soil.

If your soil has low nitrogen levels, commons signs include weak plant growth, yellowing leaves, and small or insufficient flowers and fruits. If you choose to add manure to increase nitrogen, be judicious! Too much nitrogen can burn your plants.

Soils low in phosphorous typically produce plants with stunted growth, sometimes having purple discoloration.

Plants grown in soils low in potassium often have yellowing leaves around their edges.

For a more complete list of common plant ailments, see our blog “What’s Wrong with My Tomato Plants? 10 Common Problems”.

Luckily, most gardeners find that amending their soil with compost or manure on a yearly basis is enough to address deficiencies of all three crucial nutrients, keeping the soil at healthy levels for plant growth.

Don’t Neglect Your Soil

There is no better time than now to take a minute or two to inspect your soil, make a few quick adjustments and ensure your efforts see your garden flourish as it should. Good luck!