Culling Plants, and Culling in Nature



Greenhouse with seedlings, 2009

    Not to pick up where another post left off--about first days landscaping--but every time I hear pounding rain on the stretched plastic of a greenhouse roof, I'm carried back to a January day in Petaluma, California where I logged my first day as a nursery worker.  My boss shepherded my into the little 48' x 24' hoop house, after we'd dashed from the barn.  Stepping inside the greenhouse, it sounded like being in a subway tunnel or on the tarmac of an airport next to an idling plane.  Greenhouse plastic amplifies the sound of rain, and the roar was alarming.  My assignment was to go through about 5,000 small seedling tubes of marsh plants and cull.  I had never heard that word.  So I watched as he did the first few.  Culling is a word I've since learned from this and other contexts, but I didn't know there was a real word for thinning the herd, so to speak.  It comes from Latin, where the root "coll-" meant 'to collect'.

  In nursery vernacular, 'culling' usually refers to the removal of dead plants from a large group, and the re-arrangment of that block of plants with only the remaining good, healthy ones.   Most good nurseries remove the worst living plants with the dead, as a way of upgrading the stock.  I culled pickleweed--Salicornia--for about 3 hours as water rose up through the grenhouse's gravel floor, as if the marsh plants were demanding their nursery environment seedling tubes were all sticking together and sticking to their holding trays, with roots tangled together.  It become a marsh right then and there.  It was hard on that first day to judge which live plants were weak or unhealthy enough to toss.  Something all nursery workers learn over time based on a few factors, boiled down to the idea of a standard for that nursery.  One easy guage you can try is: "Would you want to buy this one?", but that doesn't always work if someone isn't the type who buys plants at nurseries.



Deer in Ithaca suburb, 2011

    'Culling' has recently been used in relation to localized deer problems, basically meaning to reduce the total numbers by killing a significant percent of the deer herd in a given area.  I won't get into the right or wrong of that here, except to say that the nuances of the word are different from how it's use for plants in a nursery environment.  In a nursery, you wouldn't really refer to that as culling.  You might call that 'tossing plants' or 'pitching' them as a dear old friend from North Dakota used to say.  Pitching or tossing plants is something a nursery person hates to do, and only does when he has to admit he's grown too many of something to sell, and while it's a waste of money to throw plants away or compost them, it will cost more to care for them all.  But as you can see, the words are all a little different, even though they all refer in some way to reducing a quantity of a living organism for some reason.

   Nature culls its own, we know that.  Weak organisms are often easier prey; some are spared their eventual fate by the cruel pragmatism of the group: they may be eaten, killed, or abandoned to ensure they don't survive.  Evolutionary theorists argue about how animals of many kinds know to do this, or if in fact we are reading into their actions to see forethought or intent that's not really there.  But somehow they know.  It is perhaps biology's most fundamental idea--that organsisms struggle to pass along their genes to the next generation.  Barely hidden in this idea is another one: that organisms can recognize defective genes in their relatives. 

  In plants, we see a much more decorous society.  There is really no eating their own.  It's all left up to nature and her elements.  Yes, there is prey--lots of things eat plants.  But even the strongest most fit plants are stuck in place, there to be eaten by any animal willing to try.  Again the theorists: plants develop protection to defend against their sitting-duck problem.  Spines, thorns, toxic chemical compounds, rapid rejuvenation after being browsed--all these are ways plants have adapted to their fundamental flaw of being stationary.  Culling, then, comes at the hands of a more external cruelty.  As a plant you have to worry about a lot, but one thing you don't need to watch out for is being eaten by your parent, or being abandoned by one. 


Tsuga candensis, hemlock seedlings

    There's one more intriguing consideration with culling in the nursery environment.  With native plants we're growing them for their genetic diversity or their genetic specificity.  That means we either want a broad mix of genetics from within a given region to maximize appropriate options, or we want the genetics from a given habitat or location because we've decided that's what maximizes chance of survival in this particular case.  So we raise as many plants as we can, from our seed crop that meets those goals.  So should we cull the weak ones within such a subset of plants?  Once we've raised 1,000 spicebush for a project for example, should we cull out the 50 or so that are weakest and slowest to grow?  What if those end up being the most productive for seed output at maturity?  What if those happen to have a higher concentration of a compound that renders them more deer resistant?  What if the slower growers happen to be longer lived?  As a grower of native plants, we wrestle with these questions as they hide just below the surface of the more obvious decisions we make.  Some growers even argue you should save all the seed that doesn't germinate, because that reluctance--or recalcitrance as it's called in seed jargon--is precisely what these plants need in their gene pool to survive a changing climate.  After all, what better survival mechanism than not playing all your cards at once?  When you see a block of 200 columbine plants in 4" pots in the nursery, for example, not all 200 of those 200 germinated in the same tray.  We consolidate those out of the entire seed flat we sowed, based on the 200 that grew to a certain size with a certain vigor--a herd mentality, if you will.  You might call it culling, if you are feeling sorry for the ones we didn't pot up.  Or, you might call it reverse culling, or artificial selection, if you look at it from the perspective of the 200 we saved...it gets complicated.  In nature, it's Natural Selection--Darwin's key mechanism that acts on nature's raw, wild genetic stew.  But natural culling, or natural selection, plays out over time and space, massive amounts of both, which allows for the most possible factors to influence the culling.  When we do it in the nursery, it's kind of a sudden blow.  To keep the analogy warm, also consider the suddenness that comes with the 'culling' of deer.  In nature culling may happen suddenly on occasion but it is usually more of a process.

  Culling is one of those ideas that seem more and more nuanced the more you think of the concept.  Next time you buy plants, or read about 'culling' the deer population in a suburban neighborhood, think about what people really mean when they use the word...

Don't Sing to Your Plants--Sing With Them

   In the nursery one often engages in conversation about plants--with customers, with each other as staff members, and sometimes in my own head, solo.  Why does this one never grow well in pots, but it's so vigorous in the ground?  Why does this one die in the winter even though it's absolutely cold hardy in our region?  Where did I get this lone plant that's hiding out in an odd-size pot in the corner of a hoop house?  Didn't we just pot those 4 weeks ago--look at all those roots already coming out from the drain holes in the pots...whoa.  Some plants prove themselves as the nursery equivalent of excellent house guests--not necessarily doing dishes but being pleasant companions in an ephemeral sort of way.  Other plants are like the other kind of house guest--they are happy to stay as long as we let them.  All plants behave uniquely in our care and under our wings. 

   Thinking about them as unique beings is the conversation I have most often with plants.  I may sing among them, but I don't sing to them.  I feel they sing to me, and I'm grateful.  The music isn't literal--it's more like seeing music with no sound.  Conversation with these evocative creatures--truly out other half, in a cosmic sense going back to earliest evolution, but also in terms of metabolism.  They live on what would otherwise be one of our most toxic waste products, and in return they make the very air that swaddles us breathable.  It's truly hard to fathom.  So it should be no surprise that conversation with plants is an ancient, articulate, intimate affair grounded in observation and silence.  It's quiet time.

  The most beautiful thing about being a grower is just that--being a grower.  Growing plants is the beautiful part.  Creating any satisfying landscape is perhaps analogous to a chef's presentation on the plate--important, but it's an effect noticed way down at the end of the process, when the final product is in view.  Growing plants is more akin to the chef's creative act--cooking.  As growers, our conversations with plants often begin in the field, with their parents.  Some idle small talk, admiration, maybe some light flirting: "You look pretty in the early light" or "The frost brings out your natural color".  Later, we try to figure out how to allow them to germinate in our care.  There are a few basic tricks with most native plants, ways to treat the seed.  It's like anything else in life.  You find out what you need to add to the equation to make it work.  Once seedlings sprout, we as growers need to pay close attention--if you've raised kids, this stage is entirely analogous to the infant stage of human life.  Very unforgiving.  You try to control all exposure to the elements, and to anything else--too dry, too wet, too cold, too hot, one stray predator, one lapse of judgment--all have consequences.  But with seedlings, everything is sped up compared to human life, so within a few days or weeks, seedlings 'harden off'--this is a nice old-timey nursery term for toughening up, which takes a lot more than a few days or weeks for people...

   At every step, we have conversations with plants.  Most growers have these chats in our heads.  Talking about plants with other people is fun, but communing with the plants themselves is the richer language.  Raising them in this accelerated way to adolescence--when they are ready to go out on their own, into the world, into someone's garden--is sweet and wistful.  Some growers I've known don't really want to sell any of their plants.  In a comical way, they will decline sales as they walk around with a nursery customer: "Oh, no, those aren't for sale, sorry..." as they grab the flat of 4" pots and whisk them off to some fake "SOLD" area or some faux infirmary.  Of the 400+ species we raise or tend to each year, there are always a few we really don't want to part with.  It's probably how a dog breeder feels, and why some dog breeders accrue dogs over the years.  Our Nursery Manager (Kathy) grew a world-class crop of bunchberry (Cornus canadensis) two years ago, and we all really resented when people bought them.  We even priced them prohibitively, or so we thought--out the door they went.  Our latest example of this is a crop of native wild ginger (Asarum canadense) Kathy also grew from seed I collected seed in early June, near Clinton, NY.  I was lucky to stumble on a sprawling patch at its single-best seed-bearing day of the year--ripe fruit but not open yet.  Seeds of wild ginger are borne in soft, plump thumbnail-sized fruits on spindly stalks that either hide under the leaves and blend into the colors of the forest duff, or they actually slink under the duff.  Either way, very hard to see, very hard to find.  Adding complexity to shyness, the fruits open quickly, and the seeds are ferried off by ants who relish the little appendage clinging to the seed--the eliasome.  Ants probably hasten the fruits' opening as well. 

  I like to think of all our native plants in the nursery as passing through.  These particular plants, our first crop of wild ginger seedlings, grew quickly, proving to be a truly rhizomatous plant, becoming themselves in a matter of months, filling the little seedling cells with crisp white roots, then filling the next size after we transplanted them.  I also like to think of their time with us as an interlude.  We interrupt their natural cycle in the wild, but out of care, love and consummation.  Then once the seed sprouts and the seedlings are ready for life out in the world--adolescence, time to leave the nest--we send them back out to the wild.  Sometimes the wild is just that--a real woods where they can smell the leaf litter and remember the sound of the wind.  Sometimes it's a garden someone's made to mimic, or honor, the wild--a natural garden, a native landscape.  As long as there's some love there, I like to think the plants are happy to be back 'out' in the world. 

   We want that for them also.  For any native plant, life in the wild is the ideal.  Life in a garden isn't bad either if you like conversation...

Just the Fracks? Environmentalism is Patriotic, Not Political

     The question whether or not to use 'fracking' to tap underground natural gas resources in Central New York is easily one of the prime dramas playing out in our historical frame.  It's like so many other things that manifest as politics but really are just questions, aims to find out the truth, or the best way to do something.  The term 'politically correct' is overused, often when people really mean 'socially correct', or simply 'disingenuous' or 'un-genuine'.  It really means 'You may say that, but aren't your real thoughts a bit more cynical or ruthless?'.  Use of this phrase seemed to gain prominence also in our lifetimes, and seemed to really take off when open discussion of who's soft and who's tough became the defining political argument. 

     Attempts to make everything political, and the tendency for people to see more and more things as falling along political party lines, can be construed as the honest evolution of party lines in a country, America, that is still nascent and still sorting itself out.  We're still less than 250 years old as an organized sovereign entity.  But is political party line truly the keenest way to divvy ourselves up?  Especially when we really only have 2 major camps?  You want Coke or Pepsi?  Maybe we're headed for a refining of thoughts within broader parties, the early rumblings of an evolutionary set of sub-menus within the two-party model.   But the politicization of everything can also be seen as a chronic afflication, and can't be the goal of a two-party system, unless the next goal of that system is constant bickering that leads to grudges, feuds, and fighting about money, taxes, resources, power and status within the system...isn't that what the young America was trying to reject in the first place?  Can Environmentalism ever hope to exist above Politics?

     Attaching the the weight or standard of a political party to every decision is not only a grave hinderance of free thought--shouldn't we be able to hold opposing ideas in our hearts simultaneously?  Isn't that a natural condition of humanity?  Isn't that part of what makes us human?  Didn't Einstein say that?  Maybe he was wrong.  But making every dispute political also diminishes the ideas and questions at hand to a sort of sport.  Yankees or Mets?  Jets or Giants?  Flyers or Bruins?  Red or Blue?   Would it were that simple.  Yes, many decisions can be cast as political--affairs of the state, or the public, the commons, whatever you want to call it.  But too often the party itself becomes the badge that stands for a long grocery list of packaged ideas.  Instead of thinking about the ideas, we just use the brand name as a placeholder for the ideas, until we're talking in code instead of thinking.  Someone wears certain clothing, they're with this party; someone has a certain job, or drives a certain car brand, they're with that party.  Environment?  Liberals want to take food out of my kids' mouths.  Can we come back from that idea, that wanting to protect the environment means not that we love our country but that from some ivory tower we want to govern the salt of the earth?  These caricatures are taking the place of reality.

     I  have no problem saying I don't want hydrofracking to be here.  I don't.  The idea that our state DEC--Department of Environmental Conservation--seems to be functioning more as a Department of Economic Consideration is of grave concern but no surprise.  Have you ever once heard of a wetland being protected at the expense of development in our region?  To be fair, I assume that has happened--but I've never seen or heard of it happening.  There are complicated issues of public vs. private land, but if on one hand you argue that owners of private property should be able to do what they want with their land, how can you also have compulsory intergration, which says the exact opposite--that a drilling company can take things from my land even if I don't want them to?

   I also have no problem saying I think increased flooding in recent years, locally and all over, is directly related to the loss of wetlands to development.  You just can't continue to develop in wetlands, then try to acheive the same hydrologic function with man-made detention and retention ponds and culverts, and expect nature not to react.  Nature isn't reacting with a vengeance, I don't think...it's just an unfathomably complex system that has taken millions of years to reach equilibrium in so many ways, in millions of places.  If we undo that, and then try to 'fix' it again, there is no way we should expect to succeed, or at least not quickly.  You don't have to be a wetland scientist to start wondering what the effect might be of losing much of our wetlands in America.  But again, it's been made into a political issue, bundling ideas along party lines: anti-development, pro-wetland?  We know all about you, Mister.  It's my land, I can do what I want with it.  Keep government out of my life.  Except when I want it there...But what happens when each of those seemingly individual decisions starts to have collective consequences?  When individual 1/2 acre decisions are multiplied by a huge number of replicates?  It adds up.

     According to the Center for Earth and Environmental Science at Indiana University-Purdue University, Indianapolis, the US as a whole has lost over half its wetland acreage, and continues to lose more than 100,000 acres of wetlands a year.  The lower midwest (and California) has lost over 80% of its wetland acreage; only 3 states have lost 20% or fewer of their wetland acreage--Alaska, Maine and New Hampshire.  The stats are alarming but breaking them down further just numbs our sense of meaning.  Check countless other sources for similar data if you are a skeptic.  You can't continue to lose wetlands and hope to keep the functions wetlands perform.  The main ones?  Absorbing water, or slowing its flow and thereby allowing the loads of sediment, nutrients and other pollutants to settle out into the vegetation and the mud.  This is nature's erosion control--the wetland, and vegetation in general.  Wetlands are sponges.  Wring them out or throw them out, and you don't have as many sponges at work.  It's that simple.  Faster-moving water does more damage in the form of erosion, and it can't be absorbed into faux, man-made 'wetlands' or scraped-out straight-line roadside ditches when it's moving fast.  Note how, in nature, water settles out and slows down in large, generous allotments of space (again, the wetlands) that for the most part we don't create.  Our roles with wetlands are generally to learn to appreciate and love them--leaving them intact or protecting them--or to destroy them and suffer the consequences.  So flooding--is this political?  Wetlands--are they political?  Is it political to learn and understand how wetlands work, what they do?   Does it make you a weenie within your 'party' to say 'Hey, that kind of makes sense, could it be true?'...does it make you a traitor within your party to suggest that development in one place might be ok, better than development in another place (again, wetland...)?

   Loving wetlands is patriotic--they are our natural heritage, our tableau.  Those idyllic nature scenes we think of as heartland--geese and ducks landing or resting in a farm pond with vast vistas of hedgerows sharing space with fields, sunset in peach and lavender and gray--this is what we had.  Wanting to protect that has somehow become unpatriotic.  It's an aspersion to be pro-environment. 

   This is what we need to reclaim.  We need to remember to be proud of environmentalism because its core effort is to protect America from careless waste and thoughtless squandering.  For years, going back to grade school, we've been taught that nations and cultures are defined by their resources.  Does it make sense to risk one to extract another?  How about risking a few to extract one?  If we squander our fresh water, but money can be made in the act, does that make squandering better?