Healthy soil = healthy plants: most every gardener I’ve met eventually succumbs to this fundamental gardening principle. However, there are still those among us that cling to the alternatives: ritualastic applications of expensive fertilizers, sprays and laboratory cure-alls in a never-ending attempt to sustain thier garden.
Soil is alive. This may be the most important concept for a successful garden. Many of us grew up with the understanding that soil is just a sterile, lifeless accumulation of bits of rock, minerals, mud and other unknowns. The more sterile the better. As gardeners we understood that soil essentially just held our plants upright; but it was the fertilizers and chemicals that we sprayed and spread that were the source of healthy plants.
Today we now know that healthy soil is teaming with millions, no billions of unseen organisms in every shovel full. We cannot see the vast majority of these organisms and so we sometimes forget how essential they are; beneficial bacteria, fungi, algae and protozoa. Earthworms, sowbugs and springtails are all present in healthy living soil, even beneficial versions of nematodes and mites.
We now know that these organisms are essential to a soil’s fertility and health. This invisable life in your soil breaks down organic matter into nutrients, improves the structure of the soil and wards off pests and disease. Remove these organisms from your soil and your soil will soon compact, lose its nutrition, lack aeration and harbor root diseases.
We’ve established that soil is alive, and from your plants perspective, the more alive the better. So what can you do to help create soil that is even more alive?
Creating living soil begins with not killing it. As gardening consumers we are subjected to an onslought of marketing messages that eventually “teach” us how to behave in our gardens. Here are a few ways to kill a healthy living soil:
Systemic insecticides applied around roses and other plants. This is a very inneficient way to control foliage pests but a very effective way to kill your soil life.
Over cultivating. Contrary to decades of messages otherwise, soil should seldom be cultivated. Cultivating the soil, even just the surface with a hoe, does serious damage to soil life and soil structure.
Over use of pesticides, fungicides and weed products. This would seem obvious.
Over fertilizing. As odd as it may sound, too much fertilizer, especially phosphorus can be very detrimental to soil micro-organisms. The 12-55-6 “High Bloom” formulas and even the popular 15-30-15 brand may promise bigger and better flowers, but often at the expense of beneficial soil organisms.
Now that you’re not killing your soil anymore, how can you make it even better. Remember the words “Feed your Soil and Your Soil will Feed your Plants”. That’s exactly what your invisable soil life is doing. It is releasing nutrition to your plants. But, like any living thing, soil organisms need to be fed before they will in-turn feed your plants. If you don’t feed them, they will not thrive. If they do not thrive, your plants do not thrive. So feed them, feed the soil.
Feed my soil? What do I feed soil? Herein lies the lesson in this weeks column. Your soil feeds on organic material; it’s that simple. Apply ample amounts of organic composts and amendments and your soil will well. Living soil has to eat or it will die, and its eats organic material. You need to feed it.
It’s as simple as this. Get as much high-quality blended organic compost or mulch as will fit in your car and spread it all over on the top of the soil in your garden. In most areas this layer should be about two to three inches thick – really. You do not need to dig it in, in fact I suggest you do not dig it in. Just keep adding more throughout the year to maintain this organic layer on the soil. You’ll notice that it will begin to disappear after a short while. Where is it going? The invisable micro-organisms are eating it. As long as you keep feeding (adding organic material), they will keep eating and multiplying. Your soil will become healthy again; water will percolate in, diseases will deminish and your plants will thrive.
When I explain how important it is to mulch, the hardest part for most casual gardeners to understand is that they do not have to dig their soil. They can’t figure how this organic layer on top of the soil will, almost like magic, improve the soil beneath. It will; dramitically.
Where today you can barely push a shovel halfway into the hard ground, you may not even need a shovel. In that same dry, hard, dead soil where plants once struggled you will be able to dig a hole with your bare hands. Plants will grow stronger and healthier and more pest and disease free. Your soil was once dead, you fed it and now it is alive. You fed your soil, now your soil is feeding your plants.
Ron Vanderhoff is the Nursery Manager at Roger’s Gardens, Corona del Mar