Five Keys to Healthy Soil
Have you carefully nurtured, hardended off and transplanted your healthy seedlings only to see them struggle once you get them out in your garden? It could be your soil. There are five keys to healthy soil and if any one of them is off, your plants may suffer. Let’s talk about what they are and how to improve your soil if needed.
First Key – Healthy Soil Texture
Soil comes in all different colors and textures. Brown or black soil usually has a good amount of organic matter. Red, grey, or yellow soil may have a lot of minerals like iron or sulfur. All soil is made up of a mixture of clay, silt, sand, and organic matter. The texture of your soil will be determined by the ratio of clay to silt to sand. The different ratios are not necessarily good or bad, and there are things you can do to improve any soil structure.
Sandy soils allow your plants roots to grow easily, but they can leach minerals out of the soil quickly if you get a lot of rain. Clay soils are easily compacted which can make it hard for your plants’ roots to grow, but they retain nutrients and water easily. Silty soils may erode easily.
Luckily you can solve most soil texture problems by adding more organic matter. It loosens up clay soil, acts as a bonding agent to hold sandy soils together, and can slow the movement of water through silty soil reducing erosion. It also keeps a hard crust or clods of soil from forming on the surface which makes it easier for you to work the soil.
Second Key – Good Structure
The structure of the soil is also important. How loose or compact your soil is can affect your plants’ growth. Sandy soil is less compacted than clay soil, but the amount of organic matter has a big impact on soil structure. How you treat your garden soil, through tilling or other mechanical methods has a big impact on your soil structure.
Adding organic matter can also improve the structure of your soil. The natural breakdown of the organic matter also creates air pockets in the soil and pathways for water to flow or roots to grow. Types of organic matter that can help with soil structure include finished compost, grass clippings, shredded leaves, and hay or straw. You can work the organic matter into your soil, or layer it on top as mulch and allow it to incorporate into the soil as it breaks down.
Third Key – Low Acidity
Do you remember those little pink strips that you used in high school chemistry class to see if a solution was acidic, basic, or neutral? You don’t need to go buy pH strips, but how acidic your soil is can impact your plants.
Most soil tends to become more acidic over time. Your soil might have formed from more acidic rocks, or the basic elements can leach out over time or be removed when crops are harvested. Even the breakdown of organic matter can cause soil to become slightly more acidic.
Unfortunately, most plants prefer neutral or slightly basic soil. If your plants are struggling, you may need to check your soil acidity and adjust accordingly. The most traditional additive for soil that is too acidic is lime. But you can also use ground sea shells or wood ashes if those are more available in your area. Soil testing is a good idea, but if you run a woodstove or have a lot of bonfires with clean wood, adding those ashes to your garden can be a good preventative step.
Fourth Key – Low Salt Content
Another bit of soil chemistry to consider is salt content. If you water with softened water, the salt from the softener can build up in your soil. Or if you live in an area that gets salt spray from the ocean or from treated roads in the winter, there may be areas of high salt content in your garden. Or some regions may have soil that is naturally high in certain salt compounds.
One option to reduce salty soils is to collect rainwater for irrigation. If you flush out salty soil with lots of clean water, you may be able to wash the salt down below where the roots are growing. Mulching your garden areas can reduce evaporation from the soil and keep the plants from pulling salt up from down below.
Fifth Key – Enough Nutrients
There are about14 different nutrients that plants need from the soil in varying amounts to grow properly. Classic fertilizers include nitrogen, phosphorus and potassium, known as N, P, and K for their respective chemical symbols. Different plants need different ratios of these basic nutrients. But there are other minerals like calcium, magnesium, and sulfur that can cause significant problems for your plants if their soil doesn’t have enough.
Then there are micronutrients like iron and zinc that plants typically need only in tiny amounts. If your soil lacks these important elements, your plants may have growth problems. Rotating your plants to different beds can help prevent depleting your soil of a particular nutrient. Different plants need different amounts of each nutrient. Especially if you can rotate through nitrogen fixing plants like peas or beans. They can actually increase nitrogen in the soil to be used by other crops.
A soil test is a great way to find specific problems if your plants are showing signs of a nutrient deficiency. Knowing your soil nutrient levels can help you figure out how much of which fertilizers you may want to add. If you are just starting out, you can test your soil at any time. For established gardens, test at the same time each year to eliminate any seasonal variation in the results.
For general soil nutrient maintenance, organic matter like compost or mulch can help add nutrients to your soil. But it may not provide all the nutrients your garden needs. Especially after growing heavy feeding plants like tomatoes or sweet corn. Adding additional fertilizer either purchased from the store or homemade can really help your garden thrive.
How Use the Five Keys to Healthy Soil
Now that you’ve learned the five keys to healthy soil, you can start documenting and diagnosing any problems you might be facing in your garden. Does your soil texture or structure need improvement? Are you dealing with soil that is too acidic or too salty? Are you seeing problems like blossom end rot or other indications that your plants aren’t getting enough of key nutrients?
Once you know which of the five keys to healthy soil to focus on first, you can make your plan. Adding organic matter can help with a lot of soil issues. I try to add 2 – 4 inches of compost or mulch to my beds each year. If you suspect something more specific is wrong, get your soil tested. Some areas offer free soil testing, but even if you have to pay, the prices are usually quite reasonable. Paying for an accurate test could prevent you from guessing and wasting money on things your soil doesn’t actually need.
Once you’ve implemented some fixes, observe and document your results. Sometimes it can take time to see an impact. Or, it’s possible that you fixed one problem, but other issues remain. Don’t be discouraged! Building healthy soil takes time. But it is very rewarding to see your garden plants thrive once you figure out what they need.
What if your soil checks out OK and your seedlings are still struggling? Maybe they are going through transplant shock. Learn how to identify, prevent, and/or minimize the impact on your plants in my blog post How to Prevent Transplant Shock.
