It's often said that the secret to successful gardening is good soil. But what's the secret to getting good soil? I asked Jen Neve, President of Oppenheimer Biotechnology, to shed some light on the mystery.
I first met Jen in 2011 when she spoke to a group of garden writers at Moss Mountain Farm. Her company specializes in growing the microorganism Archaea. Archaea is like the Incredible Hulk of microorganisms. Aggressive, fast and tolerant of harsh conditions, it is used at oil spills to recycle contaminants into natural compounds. The microbes break down complex materials into basic nutrients and trace elements that are beneficial to plants. For this reason Archaea is also a great soil amendment, which is why you'll find it in fertilizers offered by my friends at Jobe's Organic Fertilizers.
While she was at the farm I noticed how Jen was able to take fairly complicated information and translate it into something we could all understand – sort of like Archaea! I thought she'd be the perfect person to explain the nature of good soil.
Here are the questions I posed to Jen and her responses.
Allen: A common mantra in gardening is "feed the soil, not the plants." What does this mean and how can gardeners feed the soil?
Jen Neve: Plants get most of their nutrients from the soil - so the way to have a healthy plant is to make sure your soil is healthy. When you start your garden make sure you use sand, compost and organic fertilizer and mix it into your existing soil. Microbes are hugely important and often chemicals can harm them so they may not exist in sufficient numbers in backyard soil. I suggest using an organic fertilizer that has beneficial bacteria, mycorrhizal fungi and especially Archaea. Plant whatever you want, mulch, and once or twice a year apply organic fertilizer then leave it alone. Too much digging and fiddling disturbs the root system, in fact it disturbs the whole soil structure and can harm your plants. I know I started that way – dig, dig, dig...fiddle, fiddle, fiddle - it was just more work for me without really helping the plants. So my gardening mantra is now "get it established and leave it alone."
Allen: How can a gardener tell is their soil is healthy? What do you consider to be the most important elements of healthy soil?
Jen: I think the best way to tell if your soil is healthy is to take a look at the soil. Soil is a complex assemblage of decaying organic matter, stable organic matter, fresh residue and many living organisms ranging in size from the tiny bacteria, Archaea, algae, fungi, and protozoa, more complex nematodes and micro-arthropods, to the visible earthworms, insects, small vertebrates, and even plants. The most important elements are signs of life and non-uniformity. By signs of life I mean can you see little creatures in it? Are there bits of plant matter (green as well as decaying)? Can you see grains of sand? Tiny rocks? Perhaps some leaves and sticks? Contrast that to sand in the desert – yes, it's pretty but it's uniform & for the most part lifeless.
Allen: How does Archaea contribute to soil health? How is it different from mycorrhizal fungi?
Jen: Within the soil the mycorrhizal fungi establishes a symbiotic relationship with plant roots by penetrating plant root tissues and surrounding root mass to more effectively take in needed nutrients. The Archaea are microorganisms similar to bacteria that work in the soil to release greater amounts of nutrients so the plant can take in nutrition as required. There is a natural cooperation developed between Archaea and beneficial bacteria making them more effective as a group. Archaea also breaks down organic matter into usable forms that plant roots and mycorrhizal fungi can identify, absorb, and ultimately incorporate for new growth. There has been some interesting research in Europe indicating that Archaea have an important role in the nitrogen cycle, one that is completely different than the traditional role limited to bacteria only.
You can think of the mycorrhizal fungi as an extension of the plant roots allowing the plant to use more of the nutrients the Archaea have made available.
Imagine a family all sitting around the dinner table with different kinds of food all along the center of the table – where most of the food is in unopened cans. The Archaea are the can openers, allowing the food to be available but only to the people right in front of the food. If you hand some of the people 2-foot long forks (aka mycorrhizal fungi) they can grab food from anywhere on the table - allowing them a more varied diet and therefore a healthier life.
Allen: Beyond good soil, what's your best tip for a successful garden?
Jen: Plant what grows & be patient. Seems simple but we all try to make plants grow where WE want them NOW. I always scour all the local nurseries and even big box stores looking for plants in small pots (lots of native plants) and then plant several different kinds all in one area and wait a season to see what happens. Then I buy & plant more of what thrived without extra attention from me. If a "weed" happens to grow and looks pretty then I leave it in the garden. I happen to love the wild English garden look so this method works for me. My friends all say I have a green thumb but actually, I just plant more of what has grown for me. Also, as I mentioned earlier - get the healthy soil established and just leave the soil alone.