Why Bad Things Happen to Good Plants?: On Root Problems, Root Washing, Nursery Practices and Customers

“To be, or not to be? That is the question—Whether ’tis nobler in the mind to suffer The slings and arrows of outrageous fortune, Or to take arms against a sea of troubles, And, by opposing, end them?”  Hamlet.

Is the question we face as gardeners as simple as, To ‘root wash’ or not to ‘root wash’, before planting?  To some today it has become ‘heretical’ to suggest that it might not be just a necessary corrective, but an unmitigated good…and not doing so dooms a plant to failure.  The practice of ‘root washing’ in its present form, is relatively new to gardeners.  Horticulture, which is a system of techniques, traditions and science, that goes back to our own species’ first intentional involvement growing and selecting plants, has not always included it.  Practices develop over wide spans of time.  Many are retained, others pass away. Root washing has been around as a method to assess damage to root systems, to ease and make more efficient division, to study root growth or cleanse them of particular infestations.  ‘Bare-rooting’, during a plant’s winter dormancy in temperate regions, has historically been done in the field when harvesting or transplanting many deciduous trees and woody plants for shipping and ease of transport.  In some circles today root washing has become an almost literal flash point, pitting proponent against opponent, ‘science’ against ‘tradition’…yet another fracture line to divide society. The road of the absolutist, as with many other human practices, tends to create conflict as evidence of correctness is lobbed back and forth.  My own view is that, like so many other things today, the subject is somewhat ‘grayer’. Science can be on both ‘sides’, or neither, and reality is rarely so simplistic.
If you garden in the Pacific Northwest today and reach out to any of the resources available to aid us in our practice, you have probably been made aware of ‘root washing’. Root washing, if you don’t know, refers to the several, various techniques of cleaning/removing the soil from the roots of containerized and field dug plants before we plant. It is strongly argued as a ‘corrective’ practice to deal with the root structure problems all too commonly associated with the plants we purchase from the nursery industry today. Washing generally causes less damage to the remaining roots than other strictly physical methods of dislodging the soil, so that once ‘cleaned’ the roots can be splayed out in a more or less radial pattern for proper ‘anchoring’ when planting out in the ground or even when up-potting to a larger container size. (The practice can create an issue with the wet and muddy mess of the cleaned away soil with its own ‘destroyed’ texture…what to do with it?) Today, advocates are recommending that this be a more general practice, the purpose two-folded: first, to disentangle circling or other compromising structures, of the more permanent, woody roots which could girdle the plant or restrict its growth, allowing us to redirect them; and second, to remove the soil mix itself which can potentially create a root environment which impairs the healthy growth of roots.  It is possible they may continue growing in this more ‘ideal’ soil medium avoiding a very differently textured native/surrounding soil. First the structural concerns.

Circling, girdling roots, can and do result from poor nursery practice, which may occur at any stage as a young plant is grown on to marketable size or held later for sale. It can also happen when we grow them on in pots at home.  Roots are directional. Normally they will grow out away from the woody base of the tree or shrub branching regularly, avoiding ‘obstacles’, as they seek supportive conditions, water and nutrients. Ideally this will form an expanding ‘fractal’ pattern as roots extend and branch, the larger more central and structural roots adding caliper over time, the smallest, the hair roots, continuously growing out from a zone of active growth near the tips of those ‘structural’ roots, a zone that continues outward unless somehow physically blocked. The larger woody roots form a permanent structure, which can potentially weaken a woody plant if they are forced into growing in a circular pattern. A plant cannot ‘straighten’ these roots later on its own. Plants, being what they are, are not capable of this kind of movement and correction. They are in many ways defined by a ‘fixity’ to place, with very few exceptions. The roots of woody eudicots simply continue to grow in caliper until the can’t. (The particular stories of root growth on monocots and herbaceous eudicots is slightly different and I won’t discuss it here.) This can lead to the plant girdling itself, the phenomenon of ‘J’ roots, which can occur when a plant is jammed into a pot, its roots being swept to one side, or the other problem of being planted too deeply, the root flare, that region at the base of the trunk from which the roots begin to radiate out, planted below the soil surface. Circling roots are assured when woody plants are left over long in a too small pot. Their structural, larger roots have no where to go and so begin to circle around the pot searching out what water, nutrient and air are still available in best proportion, those in the interior having more thoroughly spent what’s available in the soil volume dominated as it is by existing roots. Because of their permanent woody structure when later potted to a larger size or planted out in the ground, these roots are retained, though they may be virtually invisible within a ‘shell’ of recently added potting soil.

These structural problems are all too common in containerized stock today.  They can happen with field grown stock as well when it is planted out from containers already possessing circling roots, planted too deeply its root flare buried or pressed quickly or carelessly into the planting hole as bare root stock, its roots not positioned in a strong, somewhat symmetrical, radiating pattern. This problem can be exacerbated when the ‘planter’, perhaps to better stabilize the newly planted tree, plants the smallish root mass deeper. This latter problem can also result from our own improper planting techniques when we plant them out in the landscape or in their containers at home. You might get away with this when planting your tomatoes, but definitely not when you are planting most trees. (Always remember that in horticulture that there may be very particular exceptions to the rule. Stray from it with caution.)

The depth problem can be worsened by bad cultivation practices at the nursery when the soil surface, broken up mechanically to dislodge/kill weeds along the rows of field grown plants, is ‘kicked’ up on top of the flare over a period of what could be several years and repeated cultivations. I’m not talking about a 1/4” or so. Trees have been produced and sold, field dug, ‘balled in burlap’, ‘bnb’ or spade dug in large baskets, which are as many as 7”-8” and more inches deep, stressing the plant, causing their roots to grow upward toward better aerated soil. This creates more consequences for structure. The depth problem is often exacerbated at digging time, because the root flare, which should be at the top, is somewhere below, resulting in more than a ‘normal’ share of the roots being lost, cut off from the bottom of the ball.

Production nurseries which practice field growing must dig to harvest whether bare rooting, digging bnb or using a mechanical spade and placing them in wire baskets, the diameter of the root ball is determined at digging by trunk/stem size.  The rule of thumb was 10” of rootball diameter for each caliper inch of trunk. 1” tree – 10” ball. 2.5” trunk – 25” ball. (‘Caliper’ is the term typically used to signify the diameter of a stem or trunk, just above grade.  Larger trees are generally measured higher up on the trunk, at ‘breast height’ and you will see this measurement with the tag, ‘dbh’, the diameter at breast height, or 4.5’.  This is done because it gives a truer idea of the tree’s size. Trees are disproportionately broader at the base of their trunks to a degree varying with species and as a result of grafting to a different rootstock. We would follow the same sizing rule if we were bnb’ing a tree for transplanting in or between Parks.

Bnb’ing and spading a tree can compound this depth problem.  Picture a circle, representing the rootball, and superimpose a schematic of a tree on top of it. Now, ‘slide’ the tree down, the root flare below the top of the ball. The soil volume is effectively reduced for the roots and the length of roots shortened, ‘cut off’, by the limiting circle, of the ball. Roots are already greatly compromised, shortened and lost anytime we dig them.

All of these practices limit the size, length and strength of the woody anchoring roots, compromising its efforts to grow and may cause the plant to fail catastrophically, breaking off and falling to the ground.

Furthermore the root flare is a sensitive area where the plant transitions from above to below ground structures. Its tissues and their defenses change. Its placement in terms of depth, is critical. (Again there are a relatively few exceptions among some of the species more prone to freely suckering, such as the Willows, but never assume this.)  The collar, the area immediately above the root flare, is sensitive to below soil conditions.  It is not equipped for them. Any plant, its health compromised, is more subject to disease and infestation. Soil depth directly effects oxygen levels in the soil pore spaces.  Oxygen is necessary for gas exchange because the roots are actively metabolizing, performing the many thousands of chemical reactions within their cells critical to growth and health, releasing carbon dioxide at the same time, which must have space to evacuate in to.  This problem can be worse in the clay soils density, clay soils, generally utilized for producing bnb stock because it will hold together while digging and handling,  Such heavier soils compound the soil aeration problem when the root flare is buried. These are real problems and, sadly, they are far too common.

As a horticulturist, I have seen all of these, looked on in astonishment, or come in before the failure and attempted to correct the problem when signs became apparent or I became responsible for a property new to me and with it, a problematic tree. The depth problem is immediately evident by a trunk displaying no visible flare at the soil line, the trunk emerging straight out of the soil. Girdling issues may show themselves early on by a flare that’s ‘interrupted’, visible around only part of the trunk’s circumference, but not others, where girdling roots have stopped it. There is often the ‘telltale’ of a surface root literally wrapping around and above those extending outward from the flare, even ‘cutting’ in to the base of the trunk.  When planted, after growing on for several years, this soon becomes an all but impossible problem to correct…so it is best avoided.

There are many variables to success in planting. From the appropriateness of the species or variety that you choose, to each plant’s health and structural integrity, the time of year and the kind of problems our climate imposes, the specific conditions on our site, even a plant’s size, your prep and how you treat a plant going into the ground. It has never been enough to suggest simply, plant them “green side up, roots down”. Each of the choices we make brings with them a potential attendant suite of problems.

Planting

Planting in the Fall-Winter, often recommended in the Pacific Northwest west of the Cascades, allows our plants to grow their roots out into the surrounding soil preparing them for the coming warm summer weather and the seasonal drought that will then stress them. We can plant then here because our soils generally don’t freeze, or if they do, it rarely goes very deep, and root growth can continue throughout the ‘warmer’ parts of the season, though slowly. It can make a difference.  At the same time, in winter, our rainiest season, our soils can be saturated and working them can be damaging to their texture, causing compaction, breaking down their ‘valuable’ crumb structure, slowing percolation and drainage, decreasing soil aeration.  My preference was for planting in fall after the rains have begun, but before the soil has become saturated.  This would give a bare rooted or root washed plant the greatest opportunity to establish itself.    It is also when temperate deciduous plants normally enter their dormancy, their metabolisms greatly slowed and least likely to suffer the stress of the treatment.  Necessity plays a role in timing.  Another reason I planted in the fall-winter was because that’s when I had the time. I wasn’t running around so much simply trying to keep things alive, limiting the spread of weeds and overly aggressive ‘desirable’ plants and dealing with the ‘urban pressures’ common to all public landscapes.

What usually happens to me now is that I don’t have my plants and the site ready until spring, sometimes late.  I’m older, less flexible and less resistant to the damp cold of our winters than I once was, my motivation to get out in it again, after years of its everyday reality, is considerably reduced. Doing damage to my soil by working it wet is of greater concern to me now.   Whatever we do we should do it with awareness.  Plant selection and availability is generally greatest from the nurseries during the spring and through summer.  Garden centers all know that customers are more likely to buy a plant in flower, while showing vigor than they are in the fall when so many are looking rather plain or even bedraggled as a result of enduring summer in a smallish pot.  I would sometimes gather plants as they became available for a planned project and hold them until fall.  Most customers won’t have this patience.  There are many other questions and problems that planting presents us. Our work is almost always an ‘intervention’ into natural processes varying in its intensity of disruption.  We act and we change the world, literally. 

When I plant during the spring-summer period I don’t wash the containerized plants I’ve bought.  I don’t want to stress them anymore going into the heat and drought of summer. I do ‘loosen’ the roots at such times from their pots,  I also rarely buy large material which reduces the likelihood of root problems.  I do this also because of the cost and the significantly reduced range of choice that comes with larger sized plants because of the time investment nurseries must commit to growing them, and because larger woody plants are generally slower to establish than smaller sizes. At this stage of my garden I’m primarily buying herbaceous material which is less problematic. They don’t have woody roots. They regularly shed and replace those they have throughout the season or annually. When choosing woody plants today I tend to pick more tender species and selections, which will likely live their lives consigned to containers or I’ll commit to annual or biennial cycles of propagation to always have a younger and smaller plant to place out in the garden, the older, larger, out of scale plant removed…or replaced by another now more desirable selection. There is a fashion element to our gardens and this is my ‘playground’.

As an old gardener, trained in the trade, having studied ‘old’ plant science, I find it difficult to give up on many of the ideas and methods I learned earlier which are still supported by most of the current science I read. Many in the trade have questioned root washing as a blanket recommendation. Garden centers may choose not to replace dead plants that their customers root washed. Their businesses operate on a narrow margin and there is a lot that can go wrong if novice gardeners are also washing roots. It makes me anxious to listen to gardeners who say they wash everything. Root washing will remove most of the hair roots that actually take up nutrients and water…no matter how careful we are. Root hairs provide most of the surface area that a plant relies on to supply what it needs in terms of nutrients for its metabolic processes. The larger and more ‘permanent’ roots serve an essential structural role, perform metabolic functions and are an essential element of a plant’s circulatory system critical for the plant’s tissues and structure above. Washing will similarly effect mycorrhizal root associations reducing a plant’s ability to take up nutrients. Yes, it does make it possible to correct structural root problems and to eliminate conflicts associated with differences between the potting and surrounding native soil and the problems that may present for roots needing to extend out to anchor the plant and colonize the soil, but it would be better if this practice weren’t necessary….With smaller plants, problems will be more evident and there will be less soil ‘conflict’.  There will also be fewer times a plant is up-potted so less chance that problematic roots are ‘hidden’ from sight.  Buy small.

There are many woody plants which are root sensitive, like Magnolias, Ceanothus, Protea family species, Arctostaphylos, Daphnes, Madrone and more that I would never try this technique on. Arguably all plants are sensitive’ to root damage. It is a matter of degree. Such treatment for a plant would ‘normally’ never occur. Root washing represents a potentially catastrophic assault in any plant’s life. Massive mudslide or floods, stream banks eroding and collapsing, come to mind. These are the comparables that I see in nature. That we can get away with something does not mean that it is good for the plant. Roots live in intimate relationship with a fixed volume of soil. Movement and change there occurs only at the pace of life, as organisms, large and small, bring organic material and minerals to the soil, or tunneling through improving its aeration.  Organic waste accumulates there, falling to the ground from other plants, excreted from roots and animals, the remains of dead and decomposing plants, all waste that will decompose over time and enrich the soil. Trees and other woody plants are fixed to place their entire lives. We have introduced a never before condition of mobility. It is most definitely, not normal and it exacts a cost from any rooted plant.

What’s Going On Here?

Plants live in close, even intimate, relationship with their immediate environments.  During dormancy, whether cold or drought induced, metabolism is slowed. On dormant deciduous trees, mostly, I have much less problem with this practice. Bare rooting such trees was once common while dormant. When we used to do this, we would cut away damaged or poorly structured roots, problems which often as not were a result of our own act of digging. These problems were less common and severe on the stock we grew for ourselves. When buying a bare root tree I would always examine them, just as I would the structure of its top-growth.  (Poor above ground branching structure is arguably even a bigger problem with some nursery grown trees.) Circling/girdling roots can be devastating to a tree’s longevity as are plants grown too deep. I’ve had conifers literally fall over a few years after planting out by a predecessor because of unseen circling roots that poorly anchored them. I had a large Pin Oak, over 20″ dbh, snap off below grade because of this, barely disturbing the ground, when it failed. It looked like a giant sharpened pencil with the lead snapped off. Too many nurseries and garden centers, big box stores for whom plants are a sideline, are a problem and part of that derives from the fact that consumers, Landscape Architects, designers and local codes demand larger sizes…and low prices. So, nurseries tend to accelerate growth while some cut corners.  Too many vendors simply ignore the reality that their plants are continuing to grow in their pots…especially those for whom plants are a sideline.

My argument here, about the ‘unnaturalness’ of root washing may seem suspect to some.  Understand that i am on neither the ‘pro’ or ‘con’ side of this…there are certainly many cases where this would benefit a particular plant, and there are those many others where the benefit would be negligible especially when a plant is not suffering from poor root structure, but its been washed anyway and now must go through our summer drought season.  There are those for which such practice itself can be a fatal injury.  As a society we accept the practice of modern medicine, which can at times be very invasive!  Consider surgeries…and our use of so many drugs, the use of which, unregulated, are dangerous and toxic and could lead directly to our deaths.  Can anything be more of a direct assault on our bodies than surgery? cutting into and away at our own tissues?  We leave this to doctors, trained surgeons, to not only perform the task, but to decide when its use is called for…to assess the risk to the health of us the patient..  Yes, root washing is different…it is not done to us and yes we already commonly practice tree surgery in the form of pruning, but I would caution that it is also true that pruning is too often done badly, compromising the plant’s health and integrity as a living structure, as it attempts to grow out of it.  We do these things because we believe them right or best and dismiss many possible criticisms, because we are convinced of the ‘rightness’ of our practice….Our intentions aside, which are good, we are introducing another element of risk in our ‘patient’s’ life when we do this, and because of this, we should consider its use case by case and look to the causes that drive this and address them first.  Okay, you might concede, but we don’t have control over the bad practices of nurseries and garden centers.  Well, maybe not directly, but this is a social and economic problem and there are things we should be doing now regarding our own purchasing habits which I’ve already suggested.  Attempting to fix a problem while continuing our own related ‘behaviors’ addresses only the ‘victim’, individual by individual.  The problem will continue to be generated.

As long as a plant remains in the nursery, being ‘forced’ to grow quickly to salable size, the potential for this problem, all other things remaining  the same, will continue. ‘We’, collectively demand larger plant material.  These root problems are inevitable, at least with the dynamics as they are today. Nursery staff can be educated, well compensated and motivated, though too often they aren’t, and still we will have problems when  this or that ‘batch’ of plants gets lost in the shuffle, its up-potting delayed or a plant sitting too long on a sales bench has its root problems begun. Disentangling every such pot in the nursery as soon as it is discovered, is possible, but highly unlikely. Every time a plant is handled by staff, costs go up.  Keep in mind that nurseries and garden centers are our partners, not our enemies.

On Expectations

Nature makes no special effort to ‘save’ every individual.  Many consider nature ‘ruthless’ as it goes about ‘selectively’ favoring one individual over others without judgement, simply working to improve the health of the larger system.  In natural communities, when an individual is compromised, nature makes no special allowance nor provides any dispensation and these individuals perish, in vast uncounted numbers.  It is actually the rare tree in the forest, woodland or savannah which germinates from its seed, grows to maturity, reproduces and ‘claims’ its place for a long span of years.  We bring a different set of expectations with us to our fragile garden systems.

No nursery intentionally produces a defective product.  We need to remember this.  There product, our plants, are very much alive.  In a healthy active plant roots are growing.  When we buy a plant, we want it to be healthy and vigorous.  A plant growing in a fixed soil volume, such as when in a container, has less ‘choice’ as to where it will grow.  It is contained and limited.  Nurseries work so that every plant lives, again, something that never happens in nature. Customers don’t want plants which have been overlong in the pot and are ‘root bound’.  We don’t want plants, which lacking vigor, die when we bring them home. Customers can and do complain to garden centers about root bound plants…they also complain about plants they see as being unready for sale, too recently up-potted falling apart when removed from their pots.  Such customers are paying for the larger size, while the plant has neither filled out the pot nor produced the associated top growth.  People complain.   At what stage is a plant prime?  How long does that last?

As customers we need to take care that when we shop our expectations are not unrealistic.  Nursery stock is grown with a confined limited soil/root space.  Under no circumstances can their roots ever develop as they normally would had they begun in the ground and remained undisturbed there.  A container will inevitably redirect roots as they grow out in search of water and nutrients and their structure won’t and can’t be ideal.  This is not the nurseries ‘fault’.  Yes they can exacerbate it, but the nature of plant growth, the limits inherent to the nursery industry, produces this problem.  The nurseries are in the middle trying to make a living and supply product. They are dependent on satisfied repeat customers.  Their margin is too small and their unit price too low to be successful otherwise.  What is the operator to do?  A vigorous plant can only be held so long before it becomes problematic, but it can’t be sold too early either…..

The Problem of Soil Mixes and Nurseries
What about the soil problem i mentioned way back at the beginning? We should remember a few things from horticulture 101 and soil science as well as the reality of the nursery business. I’ll address each of these: Plant roots accomplish three things, they stabilize and anchor a plant to the ground, providing the foundation for the structures above; they possess the capacities to take up both the water and nutrients that a plant needs, with assistance from the mycorrhizal fungi they associate with, in some cases providing them the ability to share resources between individuals; and roots, and these same mycorrhizal fungi, also assist plants in their response to disease and insect attack by ‘communicating’, passing ‘signals’ through these ‘networks’ internally, with other individuals of their own species and sometimes other species if they are growing in ‘natural communities. In a very real sense they are the organs with which a plant is communication with the living soil and adjacent plants.  There is an increasing body of research which is revealing the relationships between plants and their soil environments. 

Anchorage is critical in terms of supporting the above ground portion of a plant that gathers the light and provides the plants ability to photosynthesize. This top structure, its trunk and branches, provide some assurance that a plant’s ‘claim’ to this essential light will continue. It allows it to assert this claim physically relative to its neighbors, able to present its branches and leaves in a recognizable and efficacious way. Together, roots and top structure, provide the opportunity for a more diverse and successful mixed and layered plant community that could not exist without them. Plants were once limited to a two dimensional, surface, existence, when they first evolved on dry land…many still are.

Soil is composed of specific mineral elements and highly variable organic components which can include between a hundred million and 1 billion bacteria in a single teaspoon of soil, most being decomposers, others ‘mutualists’ like the nitrogen fixing bacteria which work with plants, then there are those that may cause disease and still others that metabolize minerals in the soil including those that break down pollutants.  Along with these are the larger tunnelers and multi-celled decomposers, smaller insectivores and herbivores, all of the accumulating detritus and carcasses, literally, of now dead organisms.  Soil builds up over hundreds if not thousands of years, yet its specific living populations can change rapidly in response to a change of any of the component parts and conditions.  It changes with temperature, aeration and pH.  It changes in step with the living organisms which occupy it.  Native soils evolved in place with their animal, plant, bacterial and fungal communities. These work as a system contributing to conditions supportive of a plant’s ongoing life. Soil is not simply ‘dirt’.  The use of this term in place of ‘soil’ shows the extent of the speaker’s ignorance or indifference. 

Soils have more fixed qualities, which barring erosion and our grading of a site, remain unchanged.  This includes the soil ‘horizon’ and the mineral component parts that comprise it, the base rock from which they originated and the varying proportions of sand, loam and clay particles, along with its coarser particles and rock that may be mixed in it. All of these, mineral and organic, combine together with shed roots and exudates from plants and fungi following the climatic patterns overhead. All work together to determine the formation and maintenance of a soil’s texture, density, its friability, making possible its ‘crumb structure’ all of which contribute to the ability of roots to grow through and utilize what a soil has to offer.  This complex living and decomposing community retains much of a soil’s nutrients.  When the living landscape is scraped away many nutrients are lost immediately or easily leached away, the organisms which once held them gone.  The texture of the soil changes as well.  All of this is in a dynamic balance that will be different from species to species and place to place.  (Read about the ‘Soil Food Web.  A lot of important work has been done on this topic by Dr. Elaine Ingham. Here’s a place to start.) 

The Nursery Business and the World We Live In

The nursery industry is obviously a human invention operating outside of these historical ecological communities. A good propagator and nursery manager has to know his/her plants.  Many do so intimately and have committed their lives to both growing them and educating the public regarding their beauty, value and requirements.  Nurseries act as suppliers of plant material to local markets and buyers. They’ve selected forms based on their understanding of their customer’s preferences, their performance and beauty and are able to make them available to a public that would otherwise go wanting.  Because society has ‘chosen’ to pursue a pattern of land development which mostly devalues natural plant communities and landscapes nurseries are a necessity. Our landscape of choice, in which we live most of our lives, is market driven and places a dollar value on all assets.

Typically we prepare a site for development by clearing it of its native communities and impose our own pattern upon it, patterns that vary primarily with the density of human population intended to occupy it and the built infrastructure we ‘demand’.  With this clearing comes the loss of the soil community which once supported their landscapes. Our aesthetic which we use to redevelop a site varies within constrained limits. We are driven by fashion to some degree and limited by physical boundaries of a property, by financial as well as the legal constraints and requirements imposed by the jurisdictions within which we live. The original landscape, should we wish to reproduce it, is largely unsupportable on these lands right now, their internal ‘compass’, the several cycles that sustain it, massively disrupted; soils graded, drainage altered, with hundreds of new and often weedy species introduced while the former soil communities have collapsed…even the patterns and intensity of light and shade are changed. Add to this, our common, almost manic/neglect, on again off again pattern of landscape maintenance, especially on vacant or marginally ‘developed’ lands and we have a modern landscape held in a permanently disrupted state, actively prevented from developing any pattern of sustainable cycling, especially given our pattern of land ownership and devotion to following ‘fashion’ which can result in periodic ‘rebooting’ of landscapes, undoing previous work, however successful or not. The modern landscape, often viewed as a ‘blank slate’, or one which can be returned to such a state, is divided up into small pieces unable to sustain themselves, regardless of the design imposed on them, bereft of significant connection with others beyond their physical proximity. The stability of any landscape today is closely related to its scale and health, as well as the whims of its owners. Compromise a system’s cycles, cut it up into disparate bits and a landscape is rendered less stable and will require ongoing support to maintain itself in any kind of state. Uncared or minimally cared for sites will devolve to weedy communities of the lowest common denominator. Okay, now that was a bit harsh, but such is our overall condition….

Nurseries must, then, gauge this human driven market and determine what they can grow and sell, while also attempting to perhaps influence said market to increase their own sales. They can do this more conservatively and cater to the broadest, most common demand, or they can go after smaller niche markets and provide plants to more discriminating customers, albeit at perhaps greater economic risk to themselves. They may even attempt to steer or influence the market through their offerings, marketing and outreach. Whichever strategy they choose, as a business they must seek to perfect their production practices while keeping their costs down. This is an imperative of any business if they want to continue operating. These factors drive much within a nursery business. These, along with our ‘broken landscapes’, play a key role in the problems I’ve addressed above.

Cost control is imperative in any business. Costs tend go down when selection is limited to the tried and true, ‘bread and butter’ plants that a nursery can crank out efficiently with little loss, of course these are also the same plants many competitors are offering so the margins can be very thin and the advantage goes to the industrial strength producers. Efficiently producing a single plant ‘widget’ can simplify production greatly decreasing per unit costs, as long as the market supports it. Offering a more diverse inventory, can drive up customer interest, but can also leave a nursery/garden center holding on to stock too long as customers make their choices with both limited pocketbooks and space for plants. Plants don’t stop growing while they wait. A plant waiting in the yard or on a bench is not making money, it is, however, still growing. Potting up properly and in a timely manner adds expense, driving up the price which may reduce future sales….The seller can easily find themselves in a losing position. Some will just sit on stock. Others will hold it on, even putting it on a discount bench where roots will become even more problematic.  Others sell stock knowing it is a loser, simply to get more customers in their store to purchase more profitable items.

When sales are consistent and predictable losses are theoretically avoidable, but there are many factors complicating this including competitors trying to do the same. Choice, as I said before, can complicate matters, but it is also that which can increase future sales. It’s a conundrum. When choices are more limited, propagation and production problems are a more primary focus. Perfecting the protocols and techniques of propagation and production is a prerequisite.  It also provides a starting point when attempting to add new material to their inventories. But, there are many other factors beyond the nursery operator’s control including local, regional and national economic trends as well as weather. Many larger nurseries become more assembly line like as they attempt to control every penny of cost.  Middlemen and big box stores may be able to control the price a nursery can charge simply because they buy so much of a grower’s production.  In such a relationship a nursery’s profits depend on every penny they can cut form their production costs. For others providing specialty plants to limited niche markets can be highly stressful, even when such businesses have a developed a stable level of brand loyalty.

One of the primary production issues, after successful propagation, is choosing the ‘correct’ soil mix(es) that fit the needs of their inventory in combination with their fertilization and water schedules. Nurseries grow a product to be used elsewhere where it must grow under variable conditions including those of soil.  This is critical. It involves a balance between drainage, nutrient retention, aeration and water retention. Growing in a container is not the same as growing a plant out in soil.  Nursery grown stock must be readily ‘portable’. As discussed earlier this is a highly unnatural state for most plants. Growing contained nursery stock in native soil does not work so nurseries have experimented with many different materials that will not just support a plant, but will speed its development.  Bark, perlite, pumice, sand, vermiculite, compost, sphagnum moss, coir and various man made adjuvants are blended together with fertilizers to create potting ‘soils’.  Ideal media for speedy growth assuring that a high percentage of plants reach a salable size, quickly in a good state of health.  These may be tailored to the plant.  A nursery’s choices will vary from business to business. One is not necessarily ‘better’ than the others.  Each will entail a different set of protocols and schedules to be successful. These are blended ‘soils’. None are the soil in your garden unless you’ve hauled yard upon yard of a manufactured blend in to ‘make’ your garden.

Gardeners might add specific coarse mineral elements like pumice, 1/4-12 gravel or organic materials like compost to improve their own drainage and soil texture. They might create conditions to mimic a plant’s requirements in the form of bog, scree or crevice gardens. Lately, more nurseries and plant’s people are recommending that we just plant into our native soil to avoid other drainage and rooting problems which arise from creating different effective layers in our garden soil, layers that interrupt and slow the percolation of water down through it as well as the spread of roots. Sometimes, when ‘localized’ this can create a ‘bowl’ or teacup effect, the amended soil actually holding more water, even to the point of saturation, which can be deadly to a great many plants over our wet winter season.

Plants are effected by changes in texture, their roots tending to stay in the blended potting soil they are growing in.  When planted out they can be effectively physically constrained by the interface between two different soil textures, rather than growing out into the surrounding native soil.  By staying in this amended area or the blended soil, it is still rooted in, your plant may remain poorly anchored and subject to toppling, its roots continuing to grow circularly.  Roots that stay in the original potting soil may continue to grow, as if the pot were still in place and we can find ourselves with poor root structure.  The above ground structure can become ever more poorly anchored in place. This also leaves the unestablished plant subject to multiple stresses, drought stress over the summer as the amended soil dries more quickly than the surrounding soil and its opposite, a saturated root zone when winter rains drain into the area and are held there….Whether you actually suffer this problem depends on several things, first, the significance in difference in terms of texture, between the amended soil and the native, the more different the two are the worse the potential problem; second, a small pot may be less prone to this than a larger pot; third, whether there is a transition zone blending out the difference between the two; fourth, what you do to the rootball before you plant it out, e.g., how much you disturb the roots, do you plant without disrupting the pattern established in the pot; do you ‘score’ the sides deeply to interrupt the direction of root growth; do you ‘tease’ at least some of the large roots out and spread them when you plant; or do you wash as much of the potting soil away as you practically can, first considering the plant’s sensitivity to such disturbance; and then carefully plant without mashing the roots down in the hole. Planting a washed or bare rooted plant, is a much more labor intensive process, when done correctly, requiring that you arrange and support them as you backfill the hole.

Planting was never as easy as dropping a plant in a hole and pressing the soil in and around it. Some plants have always been more adaptable to this kind of treatment and such success encourages many to generalize.

What should we do to Assure Healthier Roots to Avoid Root Washing?

Be patient and buy smaller sizes. Grow the plants yourself from seed…in place where you intend for them to grow, ideally, a practice that more closely follows that of nature and by all means press the industry to improve its practice. Propagate yourself and trade with your friends and peers controlling root problems as they arise.  Don’t buy root bound stock no matter how seductive the price.  Understand that cutting such corners can be a result of efforts by the grower to reduce production costs or of having been held too long in a sales yard. No business will last long if it’s losing money. Customers tend to be driven by price, too often over quality and selection. Many gardeners are poorly educated regarding plant health and good structure. Many don’t understand the needs of plants and how much they can vary. Educate your fellow gardeners so that they understand the source of the problem and change their habits. Quality plants, grown well, will always be more expensive than plants grown using shortcuts. Cheap plants mean that there will be quality issues, selection issues, labelling issues and that the people doing the production and sales work may be poorly compensated. Sellers are rightly worried about raising their prices too high which will reduce the pool of potential buyers rapidly, leaving them holding unsalable product which becomes ever more ‘expensive’ to hang on to because of the labor involved in up-potting and consequent care, done correctly or not.  That is a recipe for continuing disaster. Support good practice and don’t begrudge nurseries by complaining about how expensive their plants are. They have expenses and must adequately compensate their staff if they are to go to the trouble of further training them and taking the time to do the work ‘right’. 

Creating a garden or landscape will always be relatively expensive.  It is a significant investment and commitment.  Creating an instant beautiful garden, for most of us, drives us to ‘economize’ and search out cheaper plants.  Relaxing our expectations will give us more permission to seek out the plants we want over a more realistic time period given our own budgets and resources.  Such a choice also may have the benefit of deepening our own appreciation for our gardens with the additional benefit of not having to undo rushed, or not so well thought out, decisions.  Many people who work in the plant world love what they do.  Underpaying them is the quickest way to discourage them and force them on to work elsewhere, perhaps in other industries which compensate more fairly. 

Having said all of this I do sometimes wash roots.  As noted before I’ll also score, tease and trim away damaged or circling roots. In my home garden I’ll often wash when I’m dividing particular plants at various times of the year, whenever it is best for that plant.  I used to sometimes bare root deciduous shade trees that I dug to reduce the soil weight which could rapidly escalate into several hundred to a thousand pounds or more if left it in place. I do it with all of my Bromeliaceae and many others when it is important to separate and divide them so that each has a number of roots to assure a speedier recovery.  I will do it with others when I am worried about passing perhaps unwanted interlopers on to others with the divisions, an all too frequent problem in my mature and diverse garden.  It is also useful if one has infestation problems of such pests as Root Weevils, so we don’t share that particular ‘wealth’ with them.  At such times it is essential that we can clearly see what we are doing.  Otherwise I don’t do it as a general practice. 

Crevice gardens, with their vertically aligned and closely spaced rocks, often require root washing.  These are plants that typically grow in rocky soils and have deeply penetrating roots for varying survival reasons.  In a great many cases a containerized plant simply can’t be fit between the rocks.  There is also the the bigger issues of soil problems and the fact that these deeply rooted plants require that their roots go deep.  Bunched at the rocky surface, these are much more subject to drying and over heating over summer and/or freezing during winter and  perish.  These are not your typical garden conditions nor the plants we would grow in them.  Most such plants are grown to quite small size before being planted out, often grown from seed by the gardeners themselves or by alpine/crevice garden enthusiasts and traded with others.  My understanding is also that these have a comparatively low success rate, but such a planting method is necessary for any success at all.  Again we must consider our practice by the plant and the conditions in which it will grow.  

Exceptions can also be found more broadly among succulents, epiphytes (those growing on branches) and lithophytes (those growing in rock).  For such plants anchorage is their more primary function as they have slower metabolisms and with this a reduced need for water and nutrients.  These plants generally utilize the more conservative CAM, Crassulacean Acid Metabolism, ‘pathway’ of photosynthesis rather than the more profligate C3 or C4 pathways.  Epiphytes, like those in the Bromeliaceae and the epiphytic Orchids rely more heavily on other structures, such as the specialized trichomes on their leaves, to take up water and nutrients.  Many of these often contain within their structures complex biotic communities that provide the necessary nutrients for their growth.  Physically stabilizing epiphytes when ‘planting’ them out allows them to slowly produce their thickened and modified anchoring roots.

I’ve killed too many plants already to unnecessarily risk further stressing them.  I’m also unlikely to do something as radical, there I’ve said it, to a plant with which I’m unfamiliar, because as I’ve said before, a plant’s tolerance to such ‘abuse’ is not a given.  In fact, among many of my more experienced gardener and nurseryman friends, this is a common position.  We don’t want to put a prized plant under unnecessary duress.  When I select a particular plant its health is central to my decision.  I don’t need a plant so badly that I will accept one of which I have doubts as to its quality.  I don’t shop at businesses that put quantity ahead of quality, whose workers aren’t knowledgable or passionate about the product they sell.  If ‘burned’ I won’t go back no matter how tempting the price.  I know that if I don’t get a plant right now…it won’t be the end of my world.  There will always be one I can find that I’ll treasure.  There are over 300,000 species of flowering plants, another 1,000 species of gymnosperms, the non-flowering seed producing plants and over 10 thousand ferns.  I don’t choose to get hung up on one plant, at least for very long….And, everything I just said, I sometimes make exceptions to, especially for herbaceous material.

As people we often find our lives to be far too complicated already, so we attempt to simplify when we can…but organic life is never simple and when we choose to follow such a path we will be bound to have even more disappointments.  Anyway, enough on this. I think I’ll wait a few more years to see if the science and recommendations ‘change’ again. For now, I’ll continue to take a moderate approach and pay attention to both the plant and site.

A Suggested Book

Peter Wohlleben is a forester and a particularly good observer of trees and the forests that sustain them.  His book, “The Hidden Life of Trees” presents his insights and the work of several forest ecologists and plant scientists, as he looks into what is going on beneath the bark, their relationships with their particular sites and the other members of their living communities.  Many attack his book because of the anthropomorphic tilt to his writing, his attribution of human like qualities to trees that most dismiss outright.  I suggest that you cut him some slack.  His book is written to be accessible to a more general audience.  It would seem on the surface to be too ‘sentimental’, but for me it ‘rings’ consistent with cutting edge ecological and biological science.  Were he to rely on scientific language strictly and the structure imposed by science, the ideas he presents would remain outside the understanding of many lay-readers.  We are a species that learns and retains stories more readily than we do facts on their own.  We are contextual…much the same can be said for plants.  Science does us limited good if it remains inaccessible to all but the experts.

2 thoughts on “Why Bad Things Happen to Good Plants?: On Root Problems, Root Washing, Nursery Practices and Customers

  1. John

    Wow…I can’t believe I’m the first one to leave a comment on this well written article. I have been in the horticulture/landscaping/nursery industries for over a decade now and a lot of the points you present here ring true to me. At least in my experience in the piedmont and mountains of N.C., there is a widespread lack of understanding when it comes to even the basic science of how woody plants grow and how to install them in a landscape properly. I see the same issues over and over in private, commercial and public landscapes everywhere. Unfortunately the problems caused by improper planting sometimes take years to become apparent and by then, it is often too late to remedy the situation. I also strongly agree with your stance on choosing smaller plants most of the time. Having installed hundreds of container-grown woody plants in my lifetime, I have seen some really janky root systems that never should have been allowed to grow the way they did. Most of the time, they were on larger trees and shrubs.

    Your commentary on the realities and limitations of the nursery industry are important context to this whole discussion and I wish more consumers could read your words. Thanks for the excellent read!

    Like

    Reply

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