Art, Science, and Faith

First of all, who we are and what we do.  All of the Garden Professors are in the business of the science of Horticulture.  What’s Horticulture?  The standard definition of Horticulture is the art and science of tending a garden.  Horticulture is clearly more than science but science is the foundation and underpinning.   For anyone that needs convincing that Horticulture is an art as much as a science I suggest the following exercise.  Go to a major research university and wander through their Botany or Plant Biology greenhouses. Observe the plants.  They look like crap.  The people working there are on the cutting edge of plant science; they sequence genes, they elucidate biochemical pathways but they can’t grow a plant to save their lives.   Now wander through the Horticulture greenhouse; plants are thriving, flowers are blooming.  What’s the difference?  The horticulturalists not only have the science, they have the art.  There is no denying that art and intuition play a role in growing plants, especially in ornamental horticulture where we deal with hundreds of species and cultivars, each with its own subtleties and nuances.  But as educators, especially public funded educators, how do we teach intuition?   It’s very difficult.  What we teach are principles developed through systematic scientific inquiry.  How do we know there are 17 essential elements needed for plant growth?  Repeated experiments over the years.  And our knowledge continues to evolve based on the scientific method.  I’m old enough that I learned 16 essential elements as an undergrad; the need for nickel by some plants had not yet been established.  As extension educators our role is to disseminate science-based information.  For some of us that phrase is even in our job description.  We can try to impart our experience and intuition but it’s a difficult thing.

It can be especially difficult when we deal with alternative systems for which a long-term knowledge base may be lacking.  Despite perceptions to the contrary, we are not apologists for the status quo.  Overuse and misuse of pesticides and fertilizers are rampant, especially in ornamental horticulture.  A lot of our current research and extension programming deals with reducing water and nutrient usage to reduce run-off and to reduce leaching.  I spend a lot of time telling growers things they don’t really want to hear.  How do we know growers are potentially impacting water resources? Because we and others have done the scientific research.  We’ve set out plots, we’ve fertilized, we’ve sampled leachate, we’ve measured run-off.  And we’ve conducted extension programs teaching growers that they can back off fertilization and irrigation rates without reducing crop growth.

Where we get concerned is that some assume or take on faith that because a nutrient source is ‘organic’ or ‘natural’ it’s automatically better or safer for the environment.  Is the nitrate from Chilean nitrate less likely to cause blue baby syndrome then nitrate from ammonium nitrate?   Dr. Corey Reams developed his principles as revealed to him through divine revelation.  Unfortunately most of us are not blessed with such experiences.  Instead we rely on systematic scientific investigation to develop knowledge that we share with our clients.  Personally I do not believe that faith and science are mutually exclusive.  Some of the most brilliant scientists I have met in my career have been people of deep and abiding faith.  But we need to keep each in its context.  Science is knowledge gained through systematic inquiry.  Faith is a belief system.  The central tenets of most Christian denominations are stated in the Nicene Creed which begins, “We believe in one God…”  Note it doesn’t start “We know…” or “We can prove…”  In their liturgy Catholics, “proclaim the mystery of faith; Christ has died, Christ is risen, Christ will come again.”  Not only can they not prove these things they celebrate the fact that it’s a mystery.  Faith does not demand proof.  Science does.

Friday puzzle solved!

Lots of brainstorming over the weekend, and all the answers were legitimate.  A few people came close with the observation that the roots looked like they had grown over something.  And that’s exactly right:

This is a great example of nurse log decomposition.  When the tree on the right first began growing (and it could have been decades ago), it sent lateral roots out, over, and around the nurse log to reach the soil.  As the nurse log degraded, the tree’s roots were left high and dry, outlining the girth of the original log.

Does this natural example have application in managed landscapes?  Absolutely!  As several of you pointed out, removal of soil or organic matter by erosion or decomposition can leave woody roots exposed.  If these roots are injured by feet or tools, they can lose their bark and become open to disease or pests.  These are the structural roots of the tree, and if their stability is compromised, so is that of the tree.

(Though this tree has had some injury to its roots (probably from hikers), it’s unlikely to fail as it’s pretty small. )

Friday puzzle

Finally – something else to do rather than post to the IAL blog!  On to today’s photo (and I apologize for its blurriness).

The tree in this photo is alive, and as you can see has structural roots perched well above the soil.  How might this have happened?  There are multiple possibilities.  And secondly, is there a negative impact on the tree, and if so, what?  Answers and another photo on Monday!

Have a nice weekend! 

Two new postings on compost tea efficacy – and safety

We just don’t have enough excitement on the blog, so I thought I’d bring up two new items that just crossed my virtual desk.  The first is today’s Garden Rant posting from Susan Harris.  I won’t spoil her well-written blog, but if you’ve been following the debate on the disease-control properties of compost tea, you’ll be interested in reading it.

The second was in an email from a colleague at the EPA on a new journal article.  Here’s what he said:

More potting soil and Legionella, this time in Scotland.  (Eurosurveillance, Volume 15, Issue 8, 25 February 2010).  Note that “other countries where L. longbeachae outbreaks have been reported” includes the U.S. but there is no required labeling here, though it is in Australia, New Zealand and possibly much of Europe.  Also note the association of Legionella mainly with droplets, and the possible connection to compost sprays as seem popular among do-it-yourself pesticide makers.

“The exact method of transmission is still not fully understood as Legionnaires’ disease is thought to be acquired by droplet inhalation. The linked cases associated with compost exposure call for an introduction of compost labeling, as is already in place in other countries where L. longbeachae outbreaks have been reported.”

My Favorite Drug

I love coffee, but I’m not a big coffee drinker.  On average I probably consume a cup of coffee every week or two.  Why don’t I drink it more often?  For a few reasons: First, I’m too jumpy/jittery/nervous to begin with and I don’t need this stuff making it worse, second, it tends to upset my stomach if I haven’t had a meal beforehand, and third, while I like regular coffee, the stuff that I really love are those insane fru-fru coffee drinks that you can only get at specialty shops for five or six bucks — which seems like a waste of money to me.  As you may have guessed, at this very moment, I have an overwhelming urge for a vanilla latte and so, in lieu of that, I have decided to submit this post.

Anyway, as most of you know, coffee is a horticultural crop, and so are most of the other sources from which most of us obtain our (legal) chemical stimulants like chocolate and tea.  What most people don’t realize is that the stimulants in chocolate and tea are actually somewhat different than caffeine.  Chocolate does contain some caffeine, but its major stimulant is the closely related theobromine (which doesn’t actually have any bromine in it…).  Tea (which also has very low amounts of caffeine), on the other hand contains the stimulant theophylline which is, again, closely related to, but not the same as, caffeine.

What blows me away about caffeine is how toxic it is.  If caffeine were a pesticide it would need to be labeled as category 2 (there are 4 classes with 1 being the most toxic).  Its LD50 (in other words, the amount of this chemical that, if fed to a person, would have a 50% chance of killing him/her) is estimated at about 75 milligrams per pound that a person weighs.  According to Starbucks website, one of their tall vanilla lattes contains about that much caffeine, and so you could assume that a 150 pound person could kill themselves by drinking about 150 lattes (or 150 of the smaller cups of espresso from which the coffee is made).  Additionally, though findings are inconsistent, caffeine has been linked to certain cancers.  The current thinking is that it may affect hormone levels in the body which, in turn, influence hormone related cancers like breast cancer, etc.  This research is far from conclusive, but it is concerning.

OK, so here’s the thing that’s interesting to me.  There is a small but real contingent of people out there who want to ban the herbicide 2,4 D (I picked 2,4 D randomly – I could have picked Round-up,  Sevin, or any other pesticide – but I was thinking of summer, and so 2,4 D, the most commonly used turf herbicide, is what I chose).  I’m no fan of 2,4 D and would love to see it used less frequently than it currently is, but it is a useful herbicide, particularly in the production of grassy crops (like corn).  In lawns its overuse borders on the insane.

Opponents of 2,4 D would like to see it gone, in large part, because of its toxicity and potential to cause cancer.  And, indeed, there are some studies that show that 2,4 D has the potential to cause cancer, though these findings are inconsistent and ultimately inconclusive.  Additionally, in terms of 2,4 D’s LD50, it’s about 170 milligrams per pound that a person weighs – over two times LESS toxic than caffeine.  I’m not going to bother figuring out how much 2,4 D would be in an average glass of 2,4 D because, well, I’ve never been served a cup of 2,4 D before and hopefully I never will.  (If you’re curious as to how much 2,4 D would be in a cup of spray if you scooped it right out of the spray tank — then about 50 mg is a good estimate though it could be higher or lower depending on a lot of factors).

Anyway, this leads me to a ton of further questions, the most important of which is, without doubt, do anti-pesticide activists who fear the health dangers posed by 2,4 D drink coffee?

For those of you interested in these types of questions I encourage you to look over this article: http://www.marshall.org/article.php?id=73  It is posted on the website of a conservative group (which will probably alienate some of you and make others happy) – but it was originally published a number of years ago in a well respected journal and is one of my favorite articles ever in terms of getting the old brain thinking (Please don’t get the idea that I agree with everything in the article – I do not).  Bruce Ames, one of the authors, is what we call in academia a “heavy hitter” and so, even if you don’t agree with what he says, his words are well worth reading.

The Fun Never Ends Here At Garden Professors!

I have another post to toss up later today, but first I thought I’d direct your attention to the comments on a post from a few days ago — The post titled International Ag Labs – who are they and what do they do? It’s fascinating to see so many people discussing the benefits of IAL (and more fascinating to read their comments…some of which are thoughtful and some of which are….less thoughtful).  The reason that there are so many of them is that IAL apparently sent out a blanket e-mail to their customers to try and get them to respond to Linda’s post.  This is absolutely fantastic!  I never imagined we would receive so much free publicity!

Interestingly enough I’ve been informed through a semi-reliable source that they (and the truth is that I’m not exactly sure who “they” are) want to try to get Washington State to shut our website down!  Again, awesome!  This will result in even more publicity!  We might even get into the papers!

At this point it’s probably worth telling all of you what I think about IAL based on their tests and recommendations.  Their tests look fine — not the format that I’m used to, but no big deal.  Their recommendations, on the other hand, seem silly and ill advised to me (I’ve been working with soil tests to one extent or another for about 18 years now).  That doesn’t make them wrong, but the accepted science currently out there doesn’t support them.  Also, I can’t stand it when a supposedly independent lab seems to be promoting particular products — in my opinion that could, potentially, compromises their objectivity.  Look, if you want to believe in a particular method of growing plants then that is your right — far be it from me to dictate your belief system — but, as Linda once wrote to me in an e-mail, that is faith based growing.  On this blog we talk about and support science based growing.  Faith based growers are always welcome here, but be aware that you probably won’t be happy with everything we write.

The No-Work Garden Book

Occasionally one of the GPs will blog about a book that’s particulary good – or not.  I was given a copy of Ruth Stout’s No-Work Garden Book a few years ago and frankly hadn’t given much more than a passing glance.  But last week I thumbed through it and was immediately struck by the quality of science this self-taught gardener brought to her writing.

Much of Ruth’s gardening practices included the use of organic mulch on vegetable gardens, and she regularly wrote to scientists to ask for their interpretation of “expert” advice.  Here’s an excerpt from a letter written 50 years ago by Dr. Arthur Pratt from Cornell:

“Yes, leaves, hay, straw, etc. that are not decayed or that are only partially decayed will rob the soil of nitrogen if they are mixed into the soil. But when used on top the way you use them, I have never seen a nitrogen shortage as a result of the mulch.”

So, we’ve known for at least 50 years that organic mulches don’t cause nitrogen deficiencies.  Why does this misconception persist, especially for woody mulches?

Ruth also challenged the use of plastic mulches, then relatively new to the garden product market.  She understood the benefits of a no-till approach to maintaining healthy soils.  She has a whole chapter entitled “Make Mine More Mulch.”

So here’s to Ruth Stout, the original “Mulch Queen.”

Packing Pearls

Yes, not my day to post, but I just received an email with a link to a new product called Packing Pearls.  These are polystyrene balls that fill the bottom of large containers so they aren’t so heavy.  They are promoted as “improving water drainage and oxygen flow.”  You can find a link here

The “pearls” are separated from the soil and plant roots with a pot liner (composition unknown).  We’re told that the roots can’t grow through the pot liner.  So now my question:  can a material that “improves water drainage and oxygen flow” be impervious to root growth?  Doesn’t it sound as though you’d be waterlogging the soil by installing this liner?

I honestly don’t know the answers to these questions, and the web site is not detailed (nor does it contain any links to research).  The emailed advertisement states “Tests show that flowering plants bloom two to three months longer when grown in containers with a base of Packing Pearls. Plants are also visibly healthier and hardier.”

Anyone used this system before?

A Public Service Announcement (of sorts)

File this under “short-sighted acts of government”. What, that cabinet is full to overflowing? 

In the wild world of U.S. Land Grant Universities, faculty appointments can consist of varying ratios of “the three missions”:  Teaching, Research, and Outreach.  The Cooperative Extension Service is the formalized version of outreach.  Three of us Garden Professors (Linda, Jeff, and Bert) have Extension appointments. I personally do so much outreach with both gardeners and industry that everyone thinks I’m in Extension, so I’ll consider it an honorary appointment.  

Extension does so many fabulous things for so many people, space does not allow me to even get started.  It’s not “plows and cows” anymore – urban areas receive amazing benefits in terms of environmental education, programs for K-12 (e.g. 4-H), family and consumer services, and big push over the last decade in urban horticulture.

Among all the programs Extension administers (and there are loads), the program I’m most partial to is Master Gardeners (MGs for short). I instruct training sessions, and give gardening talks across the state.  Once trained, MGs provide gazillion volunteer hours at no charge to the state, in areas as diverse as consumer horticulture to school gardening. Our campus garden utilizes volunteer hours from MGs on nearly a weekly basis

Hang in there, I’m getting to the point.

Cooperative Extension has been prone to budget cuts for quite a while now – for most states, the fat was long ago cut away, and further cuts are going straight to the bone. Imagine the alarm when out of the blue yesterday came an email update on the state’s legislative issues and actions, most of which are actions on our huge budget shortfall:

Virginia Cooperative Extension (VCE) & Agriculture Research Stations
Introduced Budget: Reduction of $1.1 million in FY1; reduction of $4.5 million in FY2
House Budget: Mandates a restructuring of VCE: Closes offices in Alexandria, Arlington, Fairfax, Norfolk, Petersburg, Portsmouth, Prince William, City of Richmond; Consolidates [an additional] 13 offices [moving to a nearby county]; Eliminates Family & Consumer Services, Community Vitality, and lawn/garden programs statewide leaving an emphasis on agriculture programs outside the urban corridor. Savings of $2.5 million in FY2.  Senate Budget: No change from introduced budget.

This proposed budget would effectively close down Extension in (by far) the most heavily populated areas of Virginia – Northern Virginia, the Richmond area, and the Virginia Beach area.  

From Dave Close, our Virginia MG Director, comes these figures:

“Statewide in 2009, our more than 5,000 VCE MG volunteers reported in excess of 334,000 volunteer hours (at a value of $6.76 million) and more than 577,000 contacts. We have right at 60 individual MG units that provide coverage of 85% or so of our counties and cities statewide.”

Dave goes on to note more good things that MGs are involved in:

1)      Environmental quality (air, water, and soil; rural-urban interface concerns such as wildland fire and how it can impact personal property and what to do to mitigate against the potential threat of wildland fire, etc.)

2)      Working with youth (school and community gardening programs for instance)

3)      Value of the landscape (economic returns from sustainably maintained landscapes – tax revenue from personal property, ecotourism, local economic development, personal savings realized from strategically planted trees in your landscape to reduce energy bills, etc.)

4)      Food safety and security (growing your own food, local food initiatives, farmer’s markets, knowing how to safely store and preserve the food you grow, biosecurity and dealing with invasive plants and pathogens, etc.)

5)      Quality of life improvement (working with populations with limited skills or abilities, working in detention centers for youth or adults giving them usable trade skills in the green industry, public health and safety issues such as mitigating against public health concerns such as west nile virus, etc.)


Now take a look at that House budget again – eliminating VCE in the most populated counties results in a one-time savings of $2.5 million.  2009 Statewide value of MG hours: $6.76 million.

 I know many, many other sectors of public service and higher education are also in critical condition.  But cash strapped state or not, I’d call this cutting your nose off to spite your face.   

Friday turf troubles

To no one’s great surprise by now, the white substance in Friday’s photo is mesh:

Like so many “instant” lawns that never really establish, the original grasses in this sod have died, leaving only weeds, debris, and the netting used as a matrix to support bunchgrass production.

(I have a personal grudge against sod netting, having removed the tenacious remains of black plastic netting when we replaced our lawn with alternative groundcoverings.  Like Velvetta and Twinkies, this stuff never dies.)