The secret to building world class soil and having a garden that is always thriving.
Having healthy soil makes all the difference in a world in your garden, but it is not as simple as adding compost… There are billions of microscopic bacteria per square inch of soil that make—up the microbiome, similar to how probiotics work in our own bellies digesting food, living bacteria in the soil breaks down food for the roots. Unfortunately most soil ecosystems have been damaged by construction, over-mulching, synthetic fertilizers, and overhead irrigation systems.
What happens when we leave soil bare between plants and irrigate it daily [or even left exposed to the elements], is that it erodes and compacts creating oxygen depleted zones. Moss tends to thrive here along with the occasional weeds that have adapted to nutrient poor soils. The solution most people go with is more mulch and more fertilizer which works temporarily, but that eventually will wash away too and further adds the problem or erosion and compaction.
Without healthy soil, gardens tend to look and feel dull to be in. Very few pollinators will come around, and it is extremely difficult to establish new plants. Everything just seems like a struggle when default to traditional gardening practices, where excessive space is left between plants and the notion of companion planting is never considered. These gardens are often planned for immediate gratification and tend to decline over-time, unless they are heavily maintained, which is not fun for anyone.
Companion plantings is the only sustainable solution for building soil, turning a desert into a lush oasis.
When a plant grows, its roots grow through clay and rock it brings moisture down to where there was little... And in the changing of seasons some roots will die, leaving long traces of organic matter extending deep beneath the soil’s surface. This oxygenates the soil and supercharges the microbiome in a way the “won’t wash” and continually gets better with time. It also means plants can grow their roots deeper together and become more drought tolerant as an inter-related, interconnected “eco-system”.
In organic farming it is common practice to use a cover crop that enriches the soil, because it is a well known fact that exposed soil will quickly turn into a desert. Some cover crops that people love to use to keep soil covered are annual rye grass or turnips, which they cut right before it goes to flower, leaving the roots to decompose in the ground over winter. Both can be found in seed packets at most garden centers. It is a step far greater for your soils long-term health, as opposed to spreading compost at the surface level.
In nature grasses and low ground-covers penetrate the top few inches of soil, then come perennials which grow deeper roots, then shrubs, then tree’s. This work highlighted beautifully by the work of Thomas Rainer and Claudia West, in their book “Planting in a Post-Wild World”. Here they have helpful diagrams that show that you can plant something like fibrous grass right on top a bulbous rooted iris, which can be planted right on top of a deep rooted flowering plant "[like Liatris spicata] with virtually no root competition - all strengthening each other by working at different layers in the soils.
The best thing we can is do plant densely and in layers. First identify what micro-ecosystem you are working with (sunny meadow, intermediary shrub layer, forest understory ect…) and then where are the inersection zones. Choose companion plants that would naturally exist in these zones with a dominant species like grass or a fern and mass plant. Plants want to tangle up their roots and touch leaves with one another. Over-crowding is of a concern, but if left alone, companion plants will naturally self-prune and move to find balance. In general it is better to over-crowd than it is to under-crowd, so don’t be afraid of planting close!
Soil is NOT meant to be left bare in our climate. So why do we do it? The answer is simple. Most landscapers focus on the flowers and not the roots. They don’t understand how what they are planting will move and grow, so they keep everything separated in little islands... Even furthermore they may plant something like water loving hydrangea, right next to something like a desert rock rose and it just makes the whole landscape very confusing to read and needs a big maintenance service to maintain.
We don’t need to do that anymore! Take time and plant your garden as a whole, not as an individual island of species. Low-maintenance is king! Soil is where we start!
We can observe the magic of “balance” in old-growth forest where microbe and plant diversity is the highest. It reads to the eye as harmony and you can have it in your garden too. The amazing part is that with selective design a little early establishment help, we don’t have to wait a thousand years to experience this feeling of richness and balance at home. Native plants and in general plants suited to our region will due more good for your yard [and mental health!] than the most expensive landscape maintenance company will every do.
The best thing anyone can ever do is to simply appreciate the life around us, and what better way to start then with our soil.
”Land is not merely soil, it is a fountain of energy flowing through a circuit of soils, plants, and animals” - Aldo Leopold