Perhaps there is no better example of living partnerships than there is between a plant’s roots and the living soil it exists in. Soil serves many purposes and is often used to protect a plant’s patrolling roots; keep a plant anchored and upright; provide a nutritious medium; help convey air and water to a plant’s roots; and provide a rich ecosystem for it to thrive in, equipped with everything from microbes to mycelia.
When we think of soil, we often don’t get the sense that it’s alive, but it is in fact teeming with life—much of which remains hidden from our view. Given that most of us don’t have a fancy electron microscope on hand to explore the depths of good dirt, the “I’ll believe it when I see it” model might not cut it. Microscopic bacteria, archaea, fungi, nematodes, and protozoa all abound in a healthy soil substrate.
Even a mere teaspoon (about 4 grams) of healthy soil in a forested area may contain anywhere from 100 million to 1 billion bacteria, which are integral to both carbon and nitrogen recycling. In that same teaspoon of soil, there may also be 1 to 40 miles (1.6 to 64 kilometers) of fungal hyphae, hundreds of thousands of protozoa, and hundreds of nematodes, not to mention nutrients and leaf matter. All of this helps contribute to the health of the plant and its seedlings. Bacteria and archaea can help release nutrients for the plant; mycorrhizal fungi can also increase nutrient uptake, provide resistance against pathogens, and help reduce overall stress. Additionally, air pollutants and other volatile organic compounds (VOCs) like benzene and formaldehyde can be siphoned through a plant and rendered harmless in the rhizosphere, otherwise known as the root-soil interface. Additionally, roots—though operating in the dark belowground—are constantly moving and communicating. It’s been shown that they can emit their own VOCs as a way to defend a plant against pathogens—further offering protection to the plant’s overall health.
When we grow plants in planters, however, we remove them from this rich environment. And if we were to take soil from outside and put it in planters, it would react in a very different way in an enclosed environment—perhaps even harming the plant. So, instead, we often need to use sterile potting mixes and then build the soil up by perhaps adding beneficial microbes, mycorrhizae, and nutrients and even aerating the potting mix as it ages. Providing plants with well-draining potting mix is particularly important as it ensures the roots remain oxygenated.
There are, of course, so many other elements that we can discuss that can benefit plants, including temperature and airflow (both of which are more fully discussed in my Houseplant Masterclass online), but if you keep these three fundamentals of light, water, and soil in mind, then you’ll be equipped to reevaluate the role you play in plants’ lives. If you have yet to get a plant for your home, then the next step is getting the one that is right for you and your conditions. Keep the above information in mind as you choose and then make a home for your plants—watch how they react to the space you put them in and think about what they might need that they aren’t getting, or even if they’re getting too much of something, like if the soil is holding too much water and asphyxiating the roots.
One simple way to get good at plant observations is to designate one day per week solely to your plants. I’ve found that it’s soul-lifting and life-affirming—so it’s as good for me as it is for my plants. That’s my Sunday—a day I really look forward to. Though I take care of my plants on the other days of the week—often walking through the house in the morning to top off anyone who needs water, deadheading any dried flowers, or picking off any dried leaves—I’ve found that having that one day devoted to my green friends makes caretaking less a quotidian chore and more of an activity to enjoy. It also helps me keep track of and observe positive or negative changes in my plants. Every day I learn from my plants; and much of what I’ve learned over the years is now being passed on to you. So go forth and plant.
Get-growing exercise: light, projection, and placement
Find the light. What direction do your windows face? If you’re not certain, take notice of where the sun rises and sets. If you still need help, most smartphones have a compass app, which can help determine the precise orientation of your windows. At what time does light enter your home? Perhaps you get soft morning light. Or hot afternoon light. How long does the light shine in your house? And does the light intensity change seasonally, if at all? Once you determine the direction, quality, and quantity of light that enters your home, begin to research what plants thrive best in those conditions.
Observe a plant and guess its needs. Next time you’re in a plant shop, stop in and take a good look at the plants. Choose one in particular and see if you can intuit where that plant is from and what kind of climate or conditions it grows in. Are its leaves thin and tapered? Fat and succulent? Are they green and glossy or gray and fuzzy? Does it have thick roots, a bulb, or perhaps thin, webby roots? All of these characteristics can be used to intuit more about the plant, and can help you become more sensitive to a plant’s care.
Make the plant cozy. Once you’ve determined which plant is most appropriate for your home, place it where you think it’ll do best. Observe it over the course of two weeks. How does it react to where it is placed? Does its stem move toward the window light? Are its leaves getting bigger? If it’s not responding well, try to place it in another area, and observe how it reacts there. Sometimes finding the best location for a plant takes time and involves a little trial and error.
From HOW TO MAKE A PLANT LOVE YOU: Cultivate Green Space in Your Home and Heart by Summer Rayne Oakes, published by Optimism Press, an imprint of the Penguin Publishing Group, a division of Penguin Random House, LLC. Copyright © 2019 by Summer Rayne Oakes.