I have been thinking a lot about weeds over the past several years. The dictionary defines "weed" as the following:
a wild plant growing where it is not wanted and in competition with cultivated plants.
This is the classic agricultural and horticultural definition. The goal then is to remove all "weeds" because their presence will reduce yield as the weeds compete for nutrients. Crops are planted in rows to make it easier to use cultivation techniques to eliminate the weeds. On a large farm this was done with a tractor. On smaller farms and in gardens it is done by a person using a hoe and or by pulling them by hand.
In the natural world, Mother Nature wants there to be a multitude of different plants, animals and other organisms growing together. As gardeners and farmers we are constantly disturbing her plan to suit our need for food and fiber, beauty, dominion over Nature and many other reasons. She never gives up. The force of plant succession is powerful and never-ending. Therefore we are always fighting weeds.
As we open our hearts and minds to the complexities of the natural system we learn how we can harness that power for our benefit. Advancements in science and technology have allowed us to begin to understand the interrelationships among plants and the microorganisms in the soil that we call the soil food web. We now know that there is communication among these organisms. In the forest it has been shown that mature trees nurse their offspring by sharing water and nutrients through the vast network of the fungal mycelia. We know that the presence of bacteria and fungi in different ratios support the growth of one type of plant over another, herbaceous perennial plants versus shrubs or trees for example. Dr. Elaine Ingham is doing work to determine how we can use that knowledge to manipulate the soil food web to control weeds in the garden or on a farm.
In the the old days herbalists, shaman, medicine men knew how to use specific plants to promote health and healing. We turned our collective backs on that for a long time but interest is being revived. I gave a talk at a local Evolver spore recently. One of the other speakers was Rob Oliver who talked about foraging for wild edible plants. He would hold up a plant and say how highly nutritious and health-giving it was and I would say oh I have that weed in my garden. After it happened about 10 times I began to think about those plants in a different way. Some I already knew were edible and some were surprising to me. The next day I went out to the garden and starting sampling some of them. Chickweed -good, violet leaves - not bad, henbit -ok, dandelion -really really bitter. I don't plan on making salads out of these every day but now I make it a point of eating some most days. Yesterday as I was pulling chickweed out of a young leek bed ( yes it does compete with the leeks) i ate some and gave the rest to the hens who love it more than I do. A friend of mine has a brain tumor which she is controlling through her diet. She can feel the tumor grow or shrink, depending on what food she eats. She says dandelion greens are particularly good at making it shrink so I harvest them for her.
We have a plant growing in the garden called creeping charlie, Gelchoma hederacea. It spreads all over the place and up until recently I have considered it a frustrating pest. It is an "invasive exotic" having been brought here from Europe because of its curative properties and because it was used to enhance the flavor and clarity of beer ( probably the main reason). Many gallons of Roundup are used every year by people (not me) trying it get rid of it. It is actually an attractive ground cover with nice purple flowers in the spring. During it's bloom time I happened to go to Dr. Richard McDonald's beneficial insect web site to see what new information was on there. He lists plants that bloom at different times of year that attract beneficial insects. He updates the list regularly and this time I saw creeping charlie on the list. I (figuratively) jumped for joy when I saw that. Whoohoo, creeping charlie has moved from my pest column to my beneficial plant column. What a relief because that stuff is everywhere. And anyway, if i keep pulling it up Ma Nature is just going to replace it with something else that might be harder to deal with. So now I keep it out of the garden beds and let it do it's thing everywhere else. It grows in abundance at the bottom of the concrete drive. With all of the flooding rains we have had recently, erosion has been on the increase. I found that where the creeping charlie has grown over the concrete it acts as a trap for the soil which I can collect and put back in the garden. The chickens like it too.
During the summer it was hot and dry. I was out hoeing weeds in the path one morning and I noticed that even though it had not rained for a couple of weeks the soil under the spreading weeds was moist. I thought to myself that maybe I was making a mistake by removing them, exposing the soil to be dried out by the sun. From then on I only removed the really nasty weeds like bermuda grass from the paths. I have always allowed dandelions to grow because they have deep tap roots that reach deeply into the soil to acquire nutrients that more shallow-rooted plants cannot. My supposition is that through the workings of the soil food web these nutrients will become available to my crops. I also leave the violets because I like the flowers and they stay in nice neat clumps, attract bees and (as i just recently learned) are edible.
This experience has taught me to be more thoughtful about the role a plant might be playing in the complex system of the garden. My musings have encouraged me to do more integrating and less segregating which has resulted in increased biodiversity in the garden benefiting my crops and making less work for myself.
One of my twitter friends tweeted this definition of a weed by Ralph Waldo Emerson which I now totally embrace:
"What is a weed? A plant whose virtues have not yet been discovered."