Weeding in a Dynamic Landscape: A Goal Oriented Strategy

The Over Thinking Series, part two

Weeding seems simple enough, but that’s the problem with simple things…they often aren’t.

Ugh! Gronk see weed??? !!!Gronk pull weed!!!

It isn’t rocket science, but we’re not stamping out widgets on a production line either…the first one the same as the 13,649th one. Landscapes are living systems containing many complex relationships and feedback loops. Just because most people don’t pay attention doesn’t mean that it’s simple.

[I’m including in my definition of weeding here hoeing (Have you noticed when you spell it you don’t, “drop the ‘e’ and add ‘ing’?”   Why don’t we go out ‘hoing’ weeds?), pulling, cutting down or dowsing with soap, Roundup or whatever chemical of plant destruction you’ve chosen. A co-worker from several years ago used to call the later, chemical hoeing. Weeding is an editing process; you remove specific plants you have designated as threats to your garden or that disrupt the aesthetic you’re going for.]

The plants you choose to weed out may be quite different than the ones I remove, as well as our timing and methods, but the plants we consider to be ‘weeds’ are mostly shared. Weeds are survivors. They are plants that possess a high degree of vigor and the adaptability to grow in poor conditions, conditions that, very often, we have created. Given the conditions within which we live weeds are the plants most common to volunteer, to spread and proliferate. They are nuisances, annoyances at best in the landscape, that some times, if enough of us can agree, we label noxious. Some, those we find to be the most aggressive spreaders we call invasive, while ecologists have another list of those capable of dominating a given landscape ‘ecosystem disrupters’. ‘We‘ as a species, have selected them over our time here as a people. We have selected them based on the way we occupy the land, by our patterns and our habits, the way we’ve built our cities and towns, our agriculture and gardens, our cultural practices and how we do business. Our selection of weeds has not been intentional, but we have been active players in the process none-the-less. Weeds are plants that are capable of growing ‘out of place’ and each of us determines what comprises the plants we go after. We make that determination based on our, largely unquestioned, shared, traditional practices and the aesthetic models we are attempting to apply to our gardens or landscapes, but it is that aesthetic and the same practices that applied over the years, over a wide area, that has both ‘created’ those particular weeds and provided the conditions in which they thrive. Change that aesthetic and those practices and you change both the actual plants that are problematic in the landscape and their ability to spread and thrive. When considering weeding and which plants you will target, we need to start asking ourselves, how, what, where, when and even, why. God, mother nature or…fill in your favorite earth deity, did not create a separate group of plants as weeds. Weeds were not a burden placed on us as if we were Job. We created them, or rather, created the conditions that have lead to their ‘success’ in our modern world. We could undo that.

[Our maintenance decisions matter in the landscape….By acting on them we help determine which weeds survive and increase…your efforts will never be perfect. Eradication quickly becomes impossible in the real world as your scale begins to increase beyond the size of a pot. If you use a particular herbicide, it works better on some species than others and you will shift the mix of weeds on the site. If you regularly till or break the soil surface, that will have an effect likely cutting and killing germinated annual weeds, displacing, chopping up and increasing many perennial weeds while bringing dormant seeds of both up from depths where conditions were not ripe for their germination.  Do you or your staff walk in the beds while working? That will lead to soil compaction that will tilt conditions toward plants, likely weeds, that are more tolerant of that while the plants you want to grow there will be inhibited. The plants you choose for your garden will create soil conditions that discourage some weeds while encouraging others as the soil chemistry, micro-flora and micro-fauna shift. Some weeds will come to predominate because their habit and foliage tends to camouflage them inside the growing plants you’ve chosen and these will tend to flower and set seed at a higher rate, increasing their number. If you periodically strip vegetative growth from the soil, the chemistry will shift with it as will the micro-flora and fauna and microbial life. Life supports life and often the relationships are very specific. Rich soils support different weeds than do those that are nutrient poor. If you bring in soil amendments and mulches or plants carrying weed seeds or propagules…if you have a well-traveled dog, they may bring in an array of seeds. What you do has a huge effect…and if you change what your doing, there is a commensurate change in the landscape.]

Look at your garden. What do you see? Plants, a collection of plants that share a common theme or design idea. They support each other aesthetically and, hopefully, belong together, complement each other and fit the site conditions. The ground was prepared for planting, the plants laid out and planted. Over the seasons each plant grows with a degree of vigor or perishes. The composition was almost certainly a simplification and probably contained components that had never occurred anywhere in the world before without our intervention. Plants naturally grow in association with one another, in communities each serving one or more roles in that community. As each grow the others ‘respond’ to it, may be leaning away, or perhaps growing with more vigor if they are beneficial associates. Some provide shade, some take up excess moisture that might threaten others, leaf litter, shed and rotting roots help retain nutrients preventing them from leaching away, while live roots work to actually improve the soil conditions as they grow and die sometimes even pulling up nutrients to be shared directly with other species through symbiotic relationships. Mycelium, growing roots, bacteria, moles and all of the incredible creepy crawlies and more join in to help aerate the soil, literally providing the ‘glue’ that binds the soil’s crumb structure thus creating the conditions for tilth and required for healthy root and plant growth. Rich soils evolved in place as a direct result of such communities and time in ways we are only beginning to understand. ‘Nature’s Gardens’ are ever evolving. They are not static landscapes that are managed to continuously reflect the designer’s intent. And, because of this they are somewhat ‘elastic’ or adaptable and can respond in nuanced ways to the forces around them. They are more than the ‘list’ you could write up while walking through them.

When we impose our designs on the land, planting in simplified sweeps, or monocultures over carefully worked grades, utilizing soils stripped from…all of these relationships are broken. Growth is the natural state of the landscape. The earth can be defined by its fecundity. Nature abhors a vacuum…. However you want to say it, landscapes are dynamic. They are alive. That is their natural state. When we scrape off a landscape, when we attempt to hold one in limbo, vacant or impose a design that has more to do with what is today considered fashionable or tasteful or utilitarian, we are imposing a human construct on a landscape that is in direct conflict with all of the natural forces and cycles in play on a particular place…weeds will flourish. The weeds are a healing response. When this wound is small enough, the response will bring about healing…but, when the scale of wound is extensive, the overall health of landscape compromised, and the practices of the constituent human community works to continually ‘tear the scab off’, the landscape is thrown out of balance and will in fact continue to decline as new challenges confront the landscape. It is completely appropriate, and even tremendously useful, to use a health model when discussing the landscape. We are effectively preventing healing and by keeping the landscape in a chronic state of ‘dis-ease’ we are making it susceptible to every new weed, insect and disease that comes along and by enabling conditions of poor plant health making it more difficult for the plants and landscape to ‘fight off’ these ‘infections’. When any plant or organism suffers from chronic poor health it becomes ever more susceptible to attack even by those things that once posed a negligible hazard. Weak plants can’t defend themselves.

So, when you are out working in your gardens, or landscapes, keep this in mind. In a small garden it is possible for many of us to keep them ‘healthy’ in spite of them being out of balance. We add amendments, fertilizers, dormant oils, compost tea, insecticidal soaps…an ever increasing range of options and products to keep them, thwarting the forces that threaten our creations. Scale can defeat any of us. Our private little Edens can go on in spite of these kinds of violations. I think you will find though that the more in tune your garden/landscape is with place the less work and resources you will have to bring in simply to assure its survival….and, I’m not talking about making improvements. I get tired of ‘fixing’ the same broken wheel every year. I have better things to do. If you are like me and still choose to practice zonal denial and follow a string of whims, at least in a part of your garden, there are still questions you should ask yourself about your design, maintenance standards and practices. Weeding is a good place to start. How, what, why, where and when. The answers lie in your garden/landscape itself. They can be found through careful observation of your own garden and those of others and how they respond to action.

 Pulling:

Weeding is a disruptive activity. That’s kind of the point. You want to end the life of a given weed/plant. This is a disruption. Pulling would seem to be the best method as your action is a more controlled and targeted tactic. You identify it and pull it out by hand or with the help of a tool like

A traditional hori-hori of the type I use

A traditional hori-hori of the type I use

a hori-hori. Sometimes a tap rooted weed might be more easily extracted with a ‘weed wrench’ (for a helpful review of the original click here) or, as I have often been want to do, using a Pony shovel to loosen the surrounding soil to ease the extraction process. We’ve all done this, probably many more times than we’d like to think about, but because of the degree of control it affords us it is often the best option especially when the weed has situated itself into a difficult to get position like inside a desirable plant. Pulling works on annual and most perennial weeds…if you get to certain perennials before they’ve established a significant root structure. Perennial weeds utilize various strategies, some resorting to a simple tap root, and can be pulled though you must be careful to extract enough of it so that it doesn’t come back later presenting an even more difficult challenge. Others may be either rhizomatous or stoloniferous. The difference is technical.

Rhizomatous roots extend in a spreading mass that stores starches and posses the genetic capacity to grow from multiple points along their length. These can be relatively shallow or several feet deep depending on the plant species and the soil condition. Stoloniferous plants have shoots, modified stem growth, that extend in a loose mass, generally relatively shallowly in the soil, and similarly store starches. Stolons possess nodes along their length where both rooting and new top growth can initiate. The effect is similar, they form spreading masses and can be difficult to impossible to pull out depending on how deep their roots run. The problem is exacerbated by the fact that often times even broken off bits of stolon or rhizome can form new plants. This particular characteristic also makes hoeing or any other form of mechanical tillage problematic on many species as the effect can be to spread the plant even more widely. This is also an issue with weeds like Yellow Nutsedge which possess ‘nutlets’, another storage organ like bulbs and tubers, on their roots that easily tear away when the soil is tilled and often, even when the plant is pulled. You face a similar problem with particular bulbous plants you wish to get rid of as they will shed bulb scales or tiny bulbs that will grow back, e.g., Scilla sp. and Allium cernuum. Know your weeds before you employ a control strategy. You may be working against yourself.

There can be another issue with pulling weeds, as the roots pull free of the soil, you break the soil surface, often pulling up a clod of the soil. Effectively, you are tilling the soil and may be creating just the right conditions for the germination of more and worse weeds. This is especially true if you are pulling out extensive colonies of weeds whether they are perennial or annual. Keep in mind that we have been selecting weeds for thousands of years and that we have been encouraging weed growth in part by our ‘tillage’ practices. Any plant has a set of preferred conditions. Weeds tend to ‘like’ the tillage practices we commonly employ.

Woody plants, including some trees like several Oak, or Quercus, species including Q. rubra, Q. palustris and Q. coccineus, some of the Maples like Acer platanoides and our infamous Scotch Broom can easily invade waste areas and beds. These woody interlopers are very adaptable to even highly degraded sites and soils, one of the reasons that we see many of these specified in plans, is that they are a kind of can’t miss plant choice…that can come back and bite us, by volunteering where they aren’t wanted. The problem with weedy trees like these Oaks, and please note that I don’t include our native Garry, or Oregon White Oak, which is actually disappearing as ever more of their habitat is developed, is that they can behave as weeds. This can be a particularly tedious, disheartening, because while you pull them out year after year the adjacent trees keep producing more acorns that will germinate in following years, and, in the case of the Oaks, a somewhat grueling task as they quickly form a thick taproot. Taking on a carrot shape, larger in caliper then the emerged stem diameter, these can be difficult to pull even in early stages of growth. For this I used to carry a small Weed Wrench (WW). This tool firmly clamped the base of the stem, spreading out the force along its slightly elongated jaws so as not to tear the top off and levered the root out. I also had two larger sized WW’s, the biggest of which had jaws that could clamp 2 ½” caliper Scotch Broom and pull it out. A great tool! Sadly, the Oregon manufacturer has closed down.  There is a new manufacturer, in Grants Pass, who has taken over offering an ‘improved’ version of Tom Ness’s original at, Uprooter, though he currently offers it in only one size. The original came in four sizes.  Other alternatives are available. (Some woody plants can be cut to the ground killing them, but many, will re-sprout, often aggressively. This will result in a multi-stemmed plant that grows back quickly while the whole time the roots continue to grow larger. This is a bad delaying technique. Somebody will hate you later as you are making future removal even more difficult. Pull or dig it out. If that is too disruptive to surrounding plantings, or physically overwhelming, learn about cut/spray techniques to kill the root crown.)

Seed Banks – a brief description (a more complete posting follows)

The soil in every landscape serves as a ‘bank’ for seeds produced or brought here. Like money in a bank seed is accumulated on and in the soil. Some of it germinates as soon as conditions are supportive, while others wait and accrue for potential germination later. Other seed, the conditions not supportive in a timely way, simply rot. The seed of every species will do this at their own varying rate. Banks also contain the seed of desirable plants. Together, with weeds, they keep a running balance that shifts between the two depending on the production of seed by the many desirable and weedy species. It is a feature of weeds in general to be very good producers of quantities of seed. It is one of their strategies for survival and, over all, they are better at it than many of the species that normally grow together in native plant communities. ‘Weed accounts’ in seed banks can grow even faster over time if weed control is not conducted in a timely manner. I’ve seen thousands of sites and gardens in which the weeds are typically left until they have begun to drop seed. People often cut them or tear them out roughly sending seed everywhere pulling them or raking them up to move later. Time does not always work in our favor. If and when a weed population gets ‘ahead’ of you, do this carefully. Consider cutting off the seed head and bagging them as you go, and, unless you are meticulous with your composting methods, haul them off site. Cut the bulk of the plant down later…and, be ready for what will come next. Weeds effect the development of any garden/landscape. Their seed will be a factor in it for years to come. Have a strategy.

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Weeding: The Over Thinking Series, part 2

 Cutting or Mowing:

This is a less direct strategy. Cutting or mowing doesn’t kill most weeds, it weakens the plant by removing tissue that now has to be replaced by utilizing starches held in its remaining tissues, or produce it anew, before it can flower and seed. It delays seeding and, if growing conditions are harsh enough, through summer heat and drought, may lead to the death of some annuals, particularly those that have to grow to a significant height, but more often weeds make an adjustment and begin to flower after cutting at a lower than customary height, mimicking the strategy often employed by gardeners to reduce top-growth of desired perennials in order to keep them from flopping open at maturity. This often results in sturdier stem growth.  I don’t often actively pursue this as a strategy…it is a fall back when the weeds get away from me.  One example follows.

There are several species of annual Brome grasses that had invaded areas I cared for along the Willamette River. It had gained a foothold in scattered areas totaling about about an acre (43,560 sq.ft.= 1 acre) of bank and was spreading quickly. These Brome are supremely adapted to disturbed sites here, especially on bare soil. They likely arrived on site from the adjacent Willamette River, although they could have come as a ‘contaminate’ in mulch or in potted plant material. In this case I think it was the river as I had applied no mulches for a couple of years when it first showed up. Neither had I been doing any planting in the immediate areas. The River, is an active corridor for the movement of weeds as seed from adjacent land finds its way into its flow with a rising level and then is deposited downstream on the banks where flow is slow and the river level drops a process that is continuous in a river. This would occur every year often bringing in weeds I’d never seen before in this landscape, or in any other landscape I was responsible for.

Pulling Brome wasn’t an option for some of the reasons discussed above. This is a very aggressive weed considered by some to be an ecosystem disrupter. It can quickly dominate a site sucking up available spring moisture needed by more desirable plants that are slower to emerge or to initiate growth. It starts its growth early and has a quick cycle from germination to maturity (it sets seed by mid-June + or -, so it is imperative that someone is paying attention and that you act in a timely manner. This often meant strapping on a string trimmer and walking the site cutting it down to the crown while trying to minimize damage to the adjacent desirable plants and weakening them. Sometimes I would switch this up by spraying, if conditions were dry, with Scythe, a contact killer, which utilizes a fatty acid, or soap. It works by dissolving the protective cuticle covering the leaf or blade causing the contacted surface to desiccate. It does not enter the plant and kill the root and if some inadvertently got on desirable plants, they wouldn’t be killed either only the contacted tissues. Either treatment would be used about three times late April through June.

Obviously mowing, either mechanically or chemically, is not a precisely targeted technique so it has limited utility, but it can be effective on annuals that get away from you if the neighboring desirable plants’ placement and growth permit it. A strategy that hits some of the desirable plants as hard as the targeted annual weeds can weaken them to such a degree that you are shifting the landscape balance in favor of the weeds. Remember, weeds are more adaptable and can respond and recover more quickly than the perennial desirables you are trying to encourage. Pay attention and pick your strategy carefully.

Mowing or cutting down can be helpful in controlling certain perennial weeds if done prior to flowering/seed dispersal. (As noted above it can also be used, if practiced with care, as a way to collect seed heads from weeds that have already begun to flower and/or set seed, like Canada Thistle. Again, carefully bag the seed. Some plants, if sprayed with systemic herbicides when already flowering, will be able to set ripe seed anyway, because systemic chemicals are relatively slow to act, so cutting and bagging is a viable control strategy). I said controlling, not killing. Perennials will rebound from cutting. Yes, you are taking energy from the plant, but perennials, particularly an established colony has a root structure that contains considerable starch and energy. Some people argue you can get rid of many perennials like the too common Himalayan Blackberry by ‘mowing’ with goats as an example. This is not a strategy many of us can use. Goats provide non-selective weed control…they may also eat what you are trying to encourage down to the ground. Mowing, whatever the specific tactic you choose, must be consistently and continuously practiced so that the recovering weeds cannot recoup the spent starches in their roots. This takes a huge commitment over what can be several years. During this time your landscape may be in limbo as planting with desirable plants will complicate your control attempts.

Himalayan Blackberry, left unchecked can grow 12’ and more tall and wide, annually!. Cutting this down and all of the canes into small pieces, can be the first part of a strategy to remove them. The second part is an appropriately timed application of a systemic herbicide. More about that later.

 Hoeing and Mechanical Tillage:

[There are all kinds of hoes and we all have our favorites and ones we can’t stand. For an incomplete list of hoes, look here. Some hoes, like the circle hoe, I tried to like, but…. I prefer hoes like the Winged Weeder or a good diamond shaped scuffle hoe that cuts in both directions. At work they supplied Hula (oscillating) hoes that I found serviceable. The standard garden hoe I’ve never liked. It seems to be designed for chopping because the blade is at almost perpendicular to the soil, but all of these must have their adherents. I’ve used these for mixing small batches of cement in a wheel barrow pushing and pulling the mix back and forth.]

I’m not big on hoeing. I’m 6’2” with back issues and the somewhat stooped body position assumed when hoeing can quickly aggravate it. Some taller people will have handles made that allow them to maintain a more upright posture. Our industrial world likes to keep things uniform and anyone much shorter or taller than average realizes this. I understand that some people actually enjoy hoeing!!! If the soil is loose and friable it is an easier proposition as you don’t have to apply so much downward force and a gliding type hoe, like some of the goose neck or diamond shaped hoes, are better able to glide below the surface where they can cut the crown away from the roots…,keep your hoe sharp! Hoeing works by either cutting off the plant just below the root crown making it unable to draw up any moisture thus thoroughly desiccating and killing the top growth and crown where the meristematic tissue is located or, particularly with small, newly emerged weeds, dislodging the whole plant, roots and all, from its previously anchored position where it can dry out on the surface. Death is most likely in the first case. Weeds dislodged by hoeing may re-root if they are otherwise undamaged and the soil moist. Remember weeds are adaptable survivors.

When I used to maintain several large, each 200-600 sq.ft., annual display beds I kept the soil in loose tilth, roto-tilling before each new wave of annuals and hoeing, pulling weeds and using a 3 or 4 tined cultivator during the season. Flowering annuals’, which tend to have less vigorous root systems greatly benefit from growing in loose soil, and because they are spaced and planted in bare soil, provide the opportunity for the quick germination and growth of any weed seed on site. This used to mean weekly hand weeding and hoeing, at least until the annual flowers covered the soil. (I never used selective pre-emergent herbicides to stop germination of particular weeds in annual beds. Some types work as a ‘root pruner’ on new roots and can have an effect on root growth of desirable plants as well, others would ‘burn off’ the tender shoots of emerging cotyledons. I was more interested in promoting plant health and found that if you practiced good mechanical control and didn’t let weeds set seed and your amendments and imported plants were clean enough, any problems would be manageable. I was regularly visiting the beds anyway for dead heading, monitoring irrigation and dealing with any vandalism issues.)

Because I mulched my display beds annually and minimized walking in them soil compaction was limited. Provide paths or stepping-stones that you can work from. Display beds and vegie gardens, both benefit from good tilth and generally require even moisture, conditions that can lead to soil compaction, if you walk in them. Again, don’t do this.

A brief note on maintenance of hoes. Hoes are edge tools intended to cut, not bash weeds into submission. Keep them sharp and clean! Everyone has a preference, mine is to use hand tools for this task, i.e., a 10” mill file. Clean your hoe after every use. Dried on clay will only make it heavier and harder to draw through the soil. Keep the surface smooth. Use a wire brush if needed. Oil it occasionally to protect it from rust and corrosion. When sharpening keep the edge uniform and not too thin as a ‘long’ thin edge maybe sharp, but it is much easier to damage, requiring that you sharpen it again. Some people like to use a bench grinder. The unskilled can eat up a lot of metal quickly with a bench grinder.

When using a weeding type hoe, not a heavy grub hoe, wield it as you would a knife, with control. The handles are light to allow this. A hoe can be partially rotated to use a corner to reach in and cut an individual weed. When hoeing remember that as the blade slides along under the surface you could also be cutting roots on desirable plants so be aware of how close you are to their crowns.

Hoeing can often be a waste of time in controlling/killing many perennial weeds. Cutting off the top of a tap rooted weed like a Dandelion, and many other similar plants, will only delay flowering, cause the plant to split into multiple crowns and result in an even larger more difficult to extract, tap-root. In general, tap-rooted weeds either need to be cleanly pulled or sprayed with a systemic herbicide.

Annual mechanical tillage, such as that done by the roto-tilling of vegetable and annual beds, can be effective, again depending on what the weed problem is. It appears to clear the slate as it chops up and buries weeds, but this is not true for many perennial weeds. Keep in mind that many established perennial weeds, particularly those with rhizomes, stolons, bulbs, tubers and other storage organs, are resistant to tillage and may even be spread by equipment and the practice of tilling. When you cut these into pieces many are capable of growing a new plant from each piece. Many spreading perennials are commercially propagated by root cuttings! Again, understand the effects of what you’re doing.

In most cases a weeding strategy other than motorized tillage will need to be utilized while the beds are in production to keep the weed seed bank from germinating its nuisance, weeds, in the bed. Yes, if you are row cropping, which isn’t generally done in landscapes or display beds, you can sometimes get in with one of the mini-tillers. I, personally, avoid using 2-cycle tools when there is a good quieter and less smelly, less polluting alternative. And, again, such tilling provides ideal conditions for the growth and germination of many types of weeds.

 Spraying/Herbicidal Control:

I am not going to write exhaustively here about this. Herbicides, including those that are approved for organic production , use their chemical properties to disrupt the normal functioning of plant growth. Monsanto would argue that everything is chemistry and so, organic or synthetic, it makes no difference. Read, The World According to Monsanto, it is an eye-opener, disturbing and, I think, an honest and relatively dispassionate look at where we are in this world today. Let me just say that certain chemicals have ‘utility’ in the landscape, whether they are derived from Chrysanthemum’s or Neem Trees or come from the Big Boys like Monsanto and BASF. They all kill their targets. They all have the potential for certain off target effects. They all give the gardener, land manager and farmer a power they would not otherwise have at their disposal. As is often the case with power some will use it responsibly and others, while perhaps following the law as described on the label, won’t. The user maybe sloppy, their judgment and their strategy can be problematic. Humans are human.

In my previous work, I sometimes sat in on meetings or consulted with peers who worked in various re-vegetation programs whose mission centered around reclaiming vast acreages from invasives on thoroughly degraded sites, sites often dominated by single species that afforded poor to no opportunity for more desirable species to find a place and thus little habitat for wildlife. This is a massive job they are attempting to do and all of them use herbicides when they are initially clearing the site. With landscapes as disturbed as these are, with so many exotic species, weeds and invasives, there is simply no other way. In a sense herbicides magnify our efforts, but it is more than that. Herbicides are not the equivalent of labor. The aggressive nature of some of these weeds, there rooting systems and the incredible seed bank that grows every year after every ‘crop’ of unthwarted, ripened and ungathered seed, pulling or otherwise attempting to deal with each plant individually on the ground doesn’t work. Many of these plants aren’t individuals, they are linked, mutually supportive colonies. Herbicides may be the only way short of excavating away vast quantities of contaminated soil. Where would we put that? How would we treat it? Ignorance can propel us along a set of misguided priorities. Weeds don’t just happen. We as a culture have played a central role in their creation and continuation. And, we are maintaining the conditions that will only make the problem worse.

How someone views weeds determines whether and how they choose to control them. In today’s black or white world where all is good or evil, little to no gray areas are allowed. For many people if it’s a weed, spray it…if it’s native volunteer, spray it…if it’s a seedling from one of the original specified plants or an interloper from a nearby landscape, it still doesn’t belong so, spray it. You certainly can. Property owners, land managers and landscape companies do this all of the time. It is easier to spray every germinating seedling than to learn and differentiate between each seedling before ‘controlling’ it. Spray them all.

In practice this is an attempt to hold the line against change. The landscape is often seen as fixed and the intention is to hold it there, but everything is working against this, all of the natural energy and nutrient cycling, all of the use and abuse, are pushing the landscape over time to something else and it is the maintenance crews who stand in the way of this. Our other landscapes, the vacant, neglected and under utilized landscapes are mostly all a mess, overgrown, trashy and weedy…and above all expected to be so. It is only us, the majority believe, who are capable of holding back the tide. This is a position taken and clung to out of ignorance and short sightedness. Our society largely subscribes to this notion that nature is chaotic and we stand alone in an effort to fend off decay, that nature too is entropic. The truth is we are too narcissistic to see or admit our role in the decline of nature and how our accepted way of life continues to degrade life around us. Our blind insistence to these destructive attitudes and practices illustrates this. We are insistent. We refuse to question these beliefs. So, we continue to view the world and our landscape, as something subject to fashion and whim. We do what we do and throw more labor at it, if we can afford to. We don’t consider that there are valuable lessons there to learn. We scoff at the idea of ‘health’ when we think of the landscape. Gaia is a story, that once had some political value, but has now fallen out of favor. It is not our herbicides, necessarily, that we use that are so terrible, it is this attitude and how it drives all of our management and design practices.


Weeding: The Over Thinking Series, part 3

Weeding is a correction. We see where things are headed and we don’t want to go there. It is a negative process. Something is being removed. As gardeners we know that when something is removed something else will grow back. Will it be desirable? Or, will our action be a net negative? If we aren’t making something better we should reconsider the action especially if its something that requires repeating. We should be headed toward more stability reducing the need for our intervention. (Granted, formal landscapes will always require our ‘intervention’.)

It is also important to see weeding as part of the process of cultivation. Cultivation is the practice of specific activities that will enhance what we choose to grow. We are removing weeds, creating space, removing competition, maybe even creating the perfect seed-bed. We are intentionally creating an imbalance in the landscape. While we may be doing this for the adjacent, established, plants, we have also improved the conditions for other plants, weeds and volunteers, to grow. If the weeds are more vigorous, adaptable and able to take advantage of the conditions of the moment, weeds will return.

When we habitually clear away weeds and leave open space, we are assuring that something, probably undesirable, will grow back, and we become locked into a fixed and continuous cycle of maintenance. Commercial and many institutional landscapes are this way and a great deal of labor is saved by maintaining open space around plants where the systematic use of herbicides is the practice to keep the ‘defensible perimeters’ around the protected plants open. With adequate spacing it is easier for applicators to limit any off target applications. It also makes it more possible to use pre-emergent herbicides to limit the range of weed species that can grow there. This strategy is most effective in landscapes where individual plants are kept separated and they are trimmed in such a way as to give them a uniform ‘edge’ and so that branching is kept clear of the ground so that it can be observed and sprayed as necessary. This simplifies maintenance for staff as it can be made more ‘one size fits all’. As you deviate from this clean and uniform approach, you complicate maintenance, raising the needed knowledge and skill level for staff, thereby increasing costs.

Weeding, how, what, why, where and when are part of the solution. When we’re out on site or in the garden surveying the work to be done, we should be keeping in mind what the goal is, what plants and conditions are in play on this particular site. Before we work our way through a patch of weeds hoeing or spraying them out with Roundup, we should have thought about the effects of this action, this time. We should ask ourselves what if we tried something else? What if we did nothing at all? Something will grow here. If it isn’t what we want right now, is it really that much of a problem? Will it serve as a temporary bridge to a more long-term solution? Are the plants I’ve planted enough to form a healthy functioning community? Do weeds keep popping up because there is some niche I haven’t addressed? Are the weeds here so aggressive that if I don’t work to eradicate them they will take over? If I show a little more patience can the developing plant community thrive and limit any problems by shading them out, allopathically inhibiting them or through root competition? Are my irrigation practices really what they need to be? Is my need for neatness pushing me to continually mess with things causing continual disturbance? Should I add another plant(s)? Should I remove a plant that, culturally doesn’t fit and my efforts to help it are disrupting the balance? I don’t really sit that much in my garden or the landscapes I’ve cared for…I fuss and putter. I wonder what if this???

Maintaining a garden/landscape is not simply a matter of establishing schedules for routine maintenance. Gardens/ landscapes are dynamic. Growth, maturation, increase, decline and death…at variable rates. We are editors when we work in the garden, constantly watching and listening, then making adjustments. Uncompromised native landscapes did not need this level of ‘participation’ because the landscape had not been so drastically disturbed.

“Oh, the Spiraea is getting out of hand, I should cut that down in early spring. The Canada Thistle is coming back over here so I need to keep an eye on that and have the sprayer at the ready when they start to bud. The Blackberry. I need to get my squirt bottle, push through the Cornus and cut and squirt the Blackberry. There’s more Blackberry seedlings sprouted over here by the Geum, gotta keep those separate. I’ll spray with a broadleaf spray on the bank and get the False Dandelion at the same time.”

Integrated Pest Management (IPM), a concept that came into more common practice in the late ‘80’s early ‘90’s, offers a helpful approach to the idea of weeds and their control. In a nutshell it directs you to carefully monitor/ observe your sites. Know which weeds are problems. Set ‘economic thresholds’, that is, at what point you take action and what action that will be. To do this well you have to know your landscape, and you need to have a good idea of how it will respond to any chosen course of action. Sometimes, when the known alternatives will be insufficient, you pay even closer attention and try something different. It provides a structure to make informed decisions. When nothing seems to work well enough, you step back, re-evaluate, and consider the design. Maybe its your own expectations…or maybe its one of those givens, those practices that you’ve always done, that need to be examined.

When you walk through your garden/landscape and you see weeds, they too are growing in association with what else is there. They are filling niches, and may in a sense, more rightly ‘belong’ where they are than what you planted. Consider this for a minute, they fill a niche or need in the landscape. They are adding something to the soil or community that your design doesn’t. (Even the invasive/ ecosystem disrupters have roots, that together with hyphae of soil fungi, form polysaccharides that serve as glue to hold soil aggregates together.) On a literally surface level this niche may be covering bare soil. Open soil in most landscapes, desert and certain alpine biomes being notable exceptions, represent an imbalance and will be ‘filled’ by a plant or plants that is available. Weeds possess the characteristics to take advantage of those opportunities. They are present in the form of seed or propagules while a more desirable plant either won’t be or does not ‘attack’ the space with such vigor. ‘The quick and the dead.’ The soil, the growing conditions, the living plants and the reservoir of plant material in the seed bank determines what will fill this space. There is a ‘rightness’ to this succession below the soil surface as well.

For millions of years, back to the advent of the first plants on earth, nature has worked, over time, to enrich soil. It evolved systems unique to each plant community, soil condition and climate to do this that work conservatively to hold and cycle the nutrients plants require to grow. Through a web of living and dying roots, fallen leaves, decaying organic matter of all types, mycelium, bacteria and the soil macro and micro-flora and fauna it captures and stores nutrients that might otherwise be leached away. Soils were not nutrient poor prior to the intervention of Man. Soils stripped of plant life, managed as mono-cultural landscapes of turf or agronomic crops or planted in contrived, generally simplistic compositions, will not possess the complexity to do this nutrient cycling. They will degrade, relatively quickly, becoming inert growing media. They lack the needed associations. Weeds may actually fill part of this role and function in the contrived landscaped. By filling the rooting zone they are holding on to some of the nutrients and maybe supporting healthier growing conditions, by supporting a healthier soil chemistry as well as the soil micro-flora and fauna.

Our maintenance practices often exacerbate this by regularly removing top growth and detritus, harvesting and removing nutrients, leaving the soil poorer. We end up in an endless cycle of removal and fertilization, in our effort to retain fertility while we continue to disrupt the healthy cycling of nutrients on site. Heavily degraded, waste/ vacant sites are often left on their own maybe receiving a sporadic herbicidal treatment or cutting down and cleaning up, maintaining them in a kind of ‘limbo’ status.

Nature works to build stability in its systems and it often does this by building in complexity. Our built and neglected landscapes are generally poorly attuned to their sites, and may be very simplified in terms of the communities we’ve created. Their constituent plants are sharing space but lack significant relationship. Natural communities, though they may look simple, contain complex relationships in which small niche players may play key roles. Weeds may help plug these holes and so may ‘belong’ more than your choices might. You chose the plants in your garden…with imperfect knowledge. Weeds found their way on their own or, by chance hitched rides and are taking the opportunities that the site offered them. I’m sure many weeds germinate on a site and die without our intervention simply because something at some critical stage was not their for them. We see the successful ones. When we plant, it is one plant at a time and we suffer with each loss. We may even ‘battle’ for our choices, it’s part of gardening. Nature has time and numbers on its side. Our created landscapes are an idea that we impose on a site. The more attuned we are to our site the more careful we are with our design idea and the more adaptable we are when we maintain the landscape, the less intrusive, disruptive, our actions will be. We become more responsible stewards.

When we see a ‘weed’, we should show a degree of patience, be thoughtful, take the time to learn about it, what conditions it will grow under, how aggressive it may spread and what its effects on its neighboring plants might be whether through direct competition for light, water or nutrients or allopathically. Can we tolerate it? Will it decline over time as more desirable plants grow and mature? Is it serving as an acceptable placeholder, keeping even more damaging weeds at bay? Or, is it an aggressive ecosystem disrupter that can dominate a landscape over time? Will it so detract from the aesthetic character of a landscape that it must be controlled, pushing you to take action? Is there another plant or group of plants you can add that will fill the niche that has been serving as the point of entry for these weeds? Are you doing what you can to control their entry from neighboring properties, waterways and traffic corridors?

The landscapes in our world today tend to be of five different types:

  1. The commercial type, which are planted simply, with a very limited range of species, grown in a very trimmed and controlled form and managed with a ‘clean’ ground strategy.  There primary purpose is to meet the requirements of local code.  After installation these areas are often neglected unless it serves the client directly to provide maintenance or they are concerned about the message a neglected landscape presents to its customer base and public.  Many of these quickly degrade.  They are often planted in narrow strips, surrounded by hard surfaces (parking lots) and serve as barriers to foot traffic, as they are intended to guide traffic often not giving people once they exit their cars comfortable choices to get to their goal.  More recently man of these ‘scapes have been built to absorb runoff from adjacent hard surfaces collecting contaminants (Many of the later are on public rights-of-way and may receive marginally more maintenance than those on private property.)
  2. More aesthetically designed gardens and landscapes, often very contrived, often marked by the inclusion of exotic species with a high degree of required maintenance.  These can be relatively short lived if the owner loses interests, has changed priorities, dies or moves away while such public spaces are subject to changing politics and shifting budget priorities.
  3. Restoration/Reveg sites that are often large scale public efforts to reclaim degraded landscapes often with an eye toward creating wildlife corridors and/or improving habitat for wildlife species.  These are generally planted with native species sourced from populations that are local and from similar though less disturbed habitats.  Because of budgets and scale these areas often receive relatively minimal followup maintenance, the expectation or hope seems to be that the plantings will have enough ‘integrity’ to stand more or less on their own.
  4. Everything else, which includes, heavily disturbed waste/vacant properties; land being held in limbo for later development; fence lines, corridors and waterways whose primary utilitarian function has removed them from consideration as bonafied landscapes; and, designed though now neglected, underfunded landscapes dominated by weeds including invasives and ecosystem disrupters, the original landscape overwhelmed and in decline.
  5. These are what I would call the ‘New Landscape’. They do not rely on a wholly local/native palette.  These are concerted efforts to create healthy landscapes with an eye on all of the elements and factors at play on a site: energy and nutrient cycling, harmonious/supportive relationships, site conditions and use as well as beauty. They require that the designer and gardener/ maintenance staff be in relationship with it. Adaptive maintenance and an idea of the landscape as dynamic and evolving are a necessity.

Landscapes are all a product of our time and they heavily influence the nature of the problems we face in our gardens and our thinking about them. Gardens and landscapes exist in context…so do we, and it takes an effort to see ‘the box’ that we live in. If we want to improve our gardens and landscapes we have to be more aware of all of the forces at work on them…and us.

See, and you thought weeding was simple!

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