(Originally published via SLIV’s blog)
Oh, they are indeed considered the bane of a gardener’s existence. Although on the flip side, they partially do keep me employed, so I can’t mind them too much!
While we’re at it though, let’s take a deeper look at weeds and the ecological role that they play by asking a few important questions. What are the persistent little buggers? Why do they keep coming back? Are they really “invasive”, “aggressive” and just out to ruin everything? Or are they something more important and beneficial? However, to answer these questions we need to delve into a key ecological concept: succession.
Succession is the process a landscape goes through when it is necessary to recover from a type of disturbance. Nowadays this disturbance is more often than not human caused, either through development or other activities such as industrial farming practices. Historically though, these types of disturbances were fires, floods, volcanic activity, earthquakes, and other catastrophic natural events. Nature abhors a blank or uncovered landscape, as it means a dangerously increased susceptibility to erosion, drought, dramatic temperature fluctuations and other further damages. To repair and heal these damaged landscapes, the process of succession is initiated.
To help the average person understand succession, I invented a neat analogy. Think of the process of ecological succession as being similar to the healing of a wound on a person. An open, raw wound is incredibly susceptible to infection, pain and further damage, so:
First, you put a bandage on the wound (what we consider ‘weeds’ aka restorative, nutrient and organic matter accumulating annual plants, which cover and protect the soil, build soil organic matter content, as well as mine nutrients from down below to begin a nutrient cycling process)
Second, a scab forms (hardy grasses and herbaceous perennials)
Third, you grow a tender scar to protect the area (shrubs, softwood deciduous trees and evergreen trees)
Finally and eventually, tough new skin (hardwood evergreens and deciduous trees, and stable, multi-layered resilient ecosystems)
In the establishment and progression of succession, plant diversity is a very important element as diversity=redundancy=resilience. Eological niches and needs are provided by numerous different plants, allowing for fluctuations due to environmental factors. If one plant species struggles, then another takes over as the primary provider of that function. This redundancy is what gives the eco-system its strength and resistance to further catastrophe. Diversity is increased furthermore by aspects such as differing elevations, geographical locations, amount of sunlight (north/south facing), soil mineral content, soil structure, micro-climates…the list goes on!
So! How does this all relate to those numerous little weeds that pop up in your garden, farm, side of the ditch, etc? I’ll use the eco-region specifics of the Pacific Northwest (as it is my home turf) to create a basis for reference. The Pacific Northwest is a very wet, warm climate (at least traditionally; let’s ignore the summer droughts of the last few years…). The soil is mineral rich, the water plentiful, and we hardly have deep snows or freezing temperatures each winter, leaving plenty of time for a long and fruitful growing season. Many centuries ago, those attributes of this eco-region used to foster the succession and eventual growth of stable, diverse, and massive cedar, hemlock and fir forests all up and down the Pacific Northwest coast. It is also very worth noting that for millienia Indigenous peoples tended and cultivated these forests to ensure the sovereign future and survival of their descendants. Barring those natural disasters I spoke of earlier, the landscapes enjoyed very little total destruction.
Cue the colonisation of this continent by Europeans and the ensuing deforestation and development. To fuel growth and industry, modern day humans have removed a substantial amount of what has naturally existed in this area for thousands (millions, even!) of years thanks to a beautiful boon of fertility. As a result of our activities there is now millions of acres of bare and disturbed soil and landscapes, however the environmental conditions of the eco-region still persist. Farming and conventional landscaping practices especially love bare soil (mulching garden beds still counts as empty soil). Thus, we have weeds! The highly evolved and resilient system we call succession is trying to take its first baby steps into creating those massive, stable, beautiful forests that once populated this area. However modern day perceptions of time are generally not grand enough to grasp that that is what eventually will take place. As it is, we love to vilify weeds and call them bad guys for simply doing their job while we perpetually create dangerously bare soil and empty ecological spaces.
The concepts I outline in this post also apply to those plants which I prefer to call opportunistic (inspired as I was by Eric Toensmeier and Dave Jacke in Edible Forest Gardens Vol. 1), such as bindweed/morning glory, ivy, japanese knotweed, purple loosestrife and many, many others. In the Pacific Northwest, these highly aggressive plants are simply filling an ecological void which almost surely human activity has created (and whose spread has been accelerated by us as well due to the increasing speed of our movement following the industrial age). When our native plants struggle due to such things as development, pollution and climate change, these more resilient plants jump in to take over and fill the void left by their dwindling numbers. As humans with our short lifespans and limited perception, it seems the end of the world! Oh no! They are disrupting the ecosystems! The truth of the matter is that the disruption of the ecosystem began long before those guys moved in. The good news in all this though is that there is growing evidence of those eco-systems’ elements adapting to these new alien denizens. Native birds, insects, bacteria, and fungi return and populations begin to grow. Diversity is admittedly low, however again, these things take time…
So! Weeds. In the ecological world, they are so very important. Yet, you don’t want to deal with them, you say? How can we minimise their presence in our gardens? I advocate changing our perceptions, to observe our surroundings, and to ask more questions. If I have weeds in my garden/farm/homestead/landscape, what is missing that these weeds are trying to replace? What sort of ecosystem does my eco-region/micro-climate support? Am I creating a disturbance or destruction of my landscape? What can I do to create what they are trying to create? What ecological niche/void needs to be filled? These questions and many more will help you understand the roles those weeds are trying to play in your landscape.
If you are struggling with how to answer these questions yourself, contact me! I’d be happy to consult with you on this matter.