The dirt in your garden, the soil, is generally perceived as the boring part of gardening. Garden soil will never be as fun and interesting as choosing what you’re going to put init, but there is a whole world under your feet that is – quite literally – the base of your garden. Fledgling gardeners are advised to put funds and efforts into improving their soil before they even consider planting anything. Not so many appreciate the inherent smarts in what they are hearing until they watch their new plants struggle to survive, demanding more food and more water. In organic gardening, we’re told, “Feed the soil and the soil will feed the plants.”
The soil in your yard supports an amazing community of insects, invertebrates and microorganisms. Adding organic matter to the soil will provide food for this array of critters and they will in turn release nutrients into the soil as they process the organic matter. These soil dwelling critters contribute more organic matter through waste and decomposition, as well as aerating the soil.
Bug sprays, fungicides and other chemicals make their way into the soil and can kill these beneficial critters living there. Synthetic or chemical fertilizers contain salt and other chemicals, which can also kill your critters as well as build up in the soil and – after time – can actually harm the plants you think you’re feeding. Also, synthetics add nothing to the actual fertility of the soil.
“But what is healthy soil?”
When looking at soil, we should consider four things: texture, structure, pH and fertility.
Texture refers to the actual size of the soil’s particles. Sandy soil has the largest particles and is of irregular shape. This is why sand feel coarse and why it drains so well. Sand doesn’t compact well at all. Silt soil contains particles that are smaller than sand but still irregular in shape. Clay has particles that are almost flat, which is why it packs so easily. Clay soil leaves hardly any room for water or air to penetrate. Sandy loam is thought to be the ideal garden soil and is made up of three textures. Don’t run out, though, and buy sand to add to your heavy clay soil. Mixing sand and clay gives you concrete.
Soil structure is how your soil clumps together. You can determine your texture by testing your structure. Squeezing a handful of damp soil into a ball and poking it lightly will tell you volumes. If it falls apart with a light poke, it’s probably sand. If you need more pressure, you’ve got silt. If you poke and poke and nothing happens, you’ve got mostly clay. A good soil structure is crumbly. This lets the roots work through it, air passes through and water drains, but not so quickly that the plants can’t use it.
There are two things that will improve your soil and they work together:
Remember those critters I talked about? Insects moving about in the soil help to aerate and they add small amounts of organic matter, the second part of improving your soil. Organic matter improves any type of soil. Compost, leaf mold, manure and green manure are all decaying organic matter. They loosen and enrich the soil and provide food for your critters. Infrequent tilling will loosen the soil structure and sometimes this is a necessity. Over-tilling can crumble the soil too much and kill the critters living there. Regular tilling is not recommended.
PH is a measure of your soil’s acid or alkaline levels. 7.0 is considered neutral. Most garden plants prefer a neutral pH range. Some plants have different requirements. Lilacs and clematis like soil with a higher alkaline level, whilst rhodies and blueberries like it a bit to the acid side.
Generally, if your plants are growing well, you pH is probably fine. If your plants are having nutrient issues or not growing vigorously, it’s worth it to get your soil tested. There are a number of pH soil testers available at a good garden center or nursery. Once you know your pH, you can begin to adjust it slowly. Some form of lime will raise pH and a form of Sulphur will lower it. Your testing kit will likely tell you what to do once you have your results in hand.
Adding lime or Sulphur is not a quick fix to the pH dilemma; it can take months to register a change and you will need to periodically retest to make sure your soil is not heading towards it’s old, original level.
Organic matter does so many fabulous things for your garden that it’s just silly not to take advantage of it. There would be no “organic” gardening without organic matter! Organic matter is how plants are fed in nature, how things are meant to be. Those good critters in your soil need to be taken care of. The more beneficial microorganisms your soil has, the less bad organisms will survive. These good critters feed on harmful microbes like nematodes and some soil born diseases. They also feed the soil when they die.
Compost is the poster child of organic matter. You can make your own or buy it in bags or by the truckload. Finished compost looks like very rich soil. Dark and crumbly with an earthy smell. Compost can be added to your garden at any time, either by turning it into the soil or mulching or top dressing. Grass clippings, leaves, vegetable peels, coffee grounds, egg shells, sawdust, straw and shredded paper are all fine things to put in your compost bin if you have one. Aged animal manure is an organic material with the added bonus of soil nutrients. Cow, sheep and chicken manure are the most popular varieties. There are others, however, that are equally acceptable. Avoid cat, dog, pig and human manures due to the risk of disease.
The nutrients in your soil are the final component in building healthy soil. Just like people, plants need certain nutrients to grow and fend off disease. Organic fertilizers are made of plant, animal and mineral sources and are basically returning what you’ve taken from the soil. They are released slowly, which means that plants can feed when they need to. Your plants will develop strong, healthy root systems because they’ll have to work a bit harder to get to the nutrients rather than living off the chemical rush of salt-based fertilizers. No sudden change in the makeup of the soil will prevent harm to your army of friendly critters.
Building healthy soil is an ongoing process. If your gardens are already established, you can always give it a boost by side- or top dressing, mulching and the addition of rich organic matter. It’s not the most fun or glamorous part of gardening, but the rewards are immeasurable.
