Category: Uncategorized

A guest blogger (sort of)

One of the best things about my job is I get to work around bright, enthusiastic young people everyday.  And not just students here at MSU.  Through conferences, meetings and other contacts I get to interact with students at other universities as well.  Over the last couple of years I have had a chance to sit in on a couple talks by Alison Stoven O’Connor, who is an Extension Agent and Ph.D. student under the direction of Jim Klett and Tony Koski in Horticulture and Landscape Archetiecture at Colorado State University (and you thought you were busy!).  For her Ph.D. research Alison is working on a subject near and dear to the hearts of the Garden Professors; nursery production and tree root development.  After I saw her talk at the ASHS meeting this summer I invited Alison to take slot as a guest blogger but she declined, citing her time constraints – we’ll call it an excused absence.  She did, however, graciously share some photos from her trial which, as you’ll see, pretty much speak for themselves.

 

A brief run-down on Alison’s study.  She grew Chanticleer pear trees in #15 containers, including both standard black plastic containers and Smart Pot fabric containers in summer 2010.  After growing the trees in the nursery for the summer, she transplanted the trees into a landscape-type planting in the fall of 2010.  Last week (remember you come to the Garden Professors to get the latest!) she began sampling the roots of a subset of her trees with the aid of a local landscape company with an air spade.  The depth of rooting appears to be consistent regardless of the type of container the tree was grown in.  Width of the root system; that’s another story… While Alison has a ways to go in gathering and analyzing data, the photographic evidence looks pretty good for the Smart pots over the status quo.

 


Trees in nursery production.

 

 


Trees in the ‘Landscape’ after transplanting,

 

 


Air spading to harvest roots


Root systems two years after planting in the landscape.  Left – tree grown in conventional black plastic pot.  Right – tree grown in Smart Pot.  630 miles between East Lansing and Minneapolis and I can already hear Jeff gloating, “Neener, neener, neener…”

Fruits and Plains

Recently there have been a number of plant related books that have done really well in terms of sales.  Brother Gardeners is one and What A Plant Knows is another.  Personally, I think both of these books are nice additions to any horticulturists bookshelf.  But there are always those books that have been forgotten.  One of those books is Fruits and Plains: The Horticultural Transformation of America by Philip J. Pauly.  Published in 2008 this is an accurate history (much more accurate that anything by Pollan for example — Not that Pollan writes bad stuff, but let’s face it, he’s a storyteller) of the evolution of horticulture in the United States over the past few hundred years — If you really want to know the history of horticulture here in the US then this is probably the best place to start.  I can’t recommend it enough.

SoMeDedTrees update

Things have settled down briefly here and I have had a chance to summarize some of the data from the container tree transplanting experiment we installed earlier this year.  For those that aren’t familiar we installed two tests this summer using 96 ‘Bloodgood’ plane trees grown in 25 gallon containers that were leftover when we completed an earlier trial in our Pot-in-Pot nursery.  I decided to use this as an opportunity to look at some tree transplanting recommendations.   With input of our GP blog readers, we installed two tests.  In both tests we applied three treatments to the tree root-balls before planting (‘shaving’ the outer roots to eliminate girdling roots; ‘teasing’ apart the rootball to eliminate girdling roots, and a control or ‘pop and drop’ to use Linda’s nomenclature).  At one site we fertilized half the trees at planting and left the others unfertilized.  At the second site we mulched half the trees with 3” of ground pine bark and left the others unmulched.

 

On the fertilizer trial we have not seen anything remarkable.  We conducted measurements of leaf chlorophyll content using a SPAD meter (a device that measures light transmittance through leaves) but did not see an effect of either fertilizer or root ball treatments.  This is not completely surprising.  In the nursery trial we fertilized the trees at standard production levels, so their nutrient status was pretty good at the outset.  What will be interesting is to see if either treatment at planting has a longer term impact.

 

In the mulch study we have seen some more immediate impacts.  We measured soil moisture to 15 cm (6”) and 45 cm (18”) inside the rootball and just outside the rootball periodically during the summer.  Soil moisture levels were consistently higher for the mulched trees that for the trees that were not mulched (Fig. 1), especially at the shallow (15 cm) depth.

Figure 1. Soil moisture of trees with and without mulch in the SoMeDedTrees study, summer 2012. (Sigmaplot wizardry by Dana Ellison)

This was reflected in tree moisture stress levels during August.  We measured predawn water potential with a pressure chamber.  Using a pressure chamber enables us to estimate the level of tension with which water is being held inside a tree.  We remove a leaf from the tree and put it in a chamber with the cut end sticking out.  We gradually increase the pressure in the chamber until we see water appear on the cut end.  The more stress the tree is under the more pressure we have to apply to get water back out. In this case, mulching, by virtue of the fact it increased soil moisture, resulted in lower water potential values, indicating less stress (fig. 2).  The root ball manipulation treatments, on the other hand, did not affect tree stress.

 

Figure 2. Mean pre-dawn water potential (in -MPa) of plane trees in the SoMeDedTrees study, August 2012.

So where does that leave us?  Well, as we’ve noted all along, this is long-term trial.  The plan is to track the trees over 3-5 years and maybe longer.  But long-term responses are the cumulative results of series of shorter-term effects.  So far, mulching appears to be the only factor that has made a difference but we are still early in the game.

An unwanted bonus in your urban chickens

Longtime reader Ray Eckhart sent me a NYT story on urban chicken eggs and lead contamination.  As I’ve mentioned before on this blog, urban gardeners should have their soils tested for lead, arsenic, and other commonly found heavy metals before they plant edibles.  Chickens that are allowed to peck and scratch in metal-contaminated soils will pass that unwanted load on to you via their eggs.

So test your soils!  It costs a bit of money, but then you know exactly what’s lurking in there.  If your soils have significantly high levels of lead or other contaminants, you can still raise chickens as long as they don’t roam your garden.

Up, up, and away…

First, let me cue the 5th Dimension.

 

I got a call the other day from the owner of a local hot air balloon company.  They specialize in fall color rides and he wanted to include some info from me about the state of fall color in Michigan this year.  Despite our concerns following this summer’s heat and drought, it turns out this year has been very good for fall color.  I think our color has been a bit more variable than usual with some trees turning early and I’m noticing many maples are dropping pretty leaves quickly once they hit peak.  Nevertheless, nature is giving us a great show. And if you’ve got a little extra spending money, there’s probably no better way to see it than from a beautiful balloon…

Photos: Scott Lorenz, Westwind Balloon Co.

 

 

</d

When all else fails…

As someone who has had a foot in Horticulture and a foot in Forestry throughout most of my career, people often ask me to compare the two disciplines.  One of the truisms that applies in both cases is, “When all else fails, blame the nursery.”  I’ve seen this following seedling die-offs in industrial forest plantations and I’ve seen it many, many times after street tree or landscape planting failures.  In fact, if you believe some people, tree nurseries are responsible for every plague and pestilence to ever afflict mankind.  Are some tree failures related to things that happened in the nursery?  Of course.  But there are lots of things that can go wrong between a nursery and a tree’s final destination; and even more things that can go wrong after it’s planted.

I know a lot of people don’t believe this, but nursery growers want their trees to survive and grow well after they leave their care.   Growing trees is like making cars and any other business.  You need satisfied customers if you expect to have repeat business.  The best growers are always looking at their production practices for ways to improve their product.  Last week I visited Korson’s tree farm in central Michigan.  Korson’s grows Christmas trees and B & B landscape conifers.   Rex Korson, the owner, has been concerned over the impact of root loss during transplanting of landscape trees.  So much so, in fact, that he is conducting his own trial on root pruning.

For those that are not familiar, root pruning of B & B trees is usually done a couple years before harvest by using a tree spade to severe tree roots.  The spade used for pruning is slightly smaller than the one used for harvest, so that new roots stimulated by pruning are harvested with the root ball.  Does it work?  I did a root pruning trial a few years back to see if it could improve survival of fall-planted oaks and had mixed results.  For Rex’s trees, however, the initial results were pretty impressive.  In the first photo below are root systems of Norway spruce trees dug with a 30” tree spade.  The second photo shows the root systems of trees dug with the 30” spade that had been root-pruned last October with a 24” tree spade.  The response in one-year’s time was dramatic.  At this point there no out-planting data but, other factors being equal, increasing the amount of roots harvested with the tree should increase transplant success.

I should hasten to point out that Rex is not alone.  I work with many other growers in the state that are constantly tinkering with this or that in their production systems; sometimes on their own, sometimes with university specialists or extension educators.  I’m not so Pollyanna to think that everything is always rosy in the nursery world but most growers, especially the better ones, are aware of the issues out there and are working to build a better tree.

Spruce dug with 30″ spade without root pruning

Norway spruce root-pruned in Oct 2011 with a 24″ spade and dug Oct 2012 with a 30″ spade.


Close up of new fine roots


Tree spade mounted on excavator for root pruning.  With this system an operator can root prune 8 trees in 5 minutes.

</d

Pennsylvania is for…..Snake Oil?

This year at the Philadelphia Flower Show there were a few groups talking about compost tea.  Meadow Brook Farm, a farm owned by the Pennsylvania State Horticultural Society is one, and another is F2, a company that provides “Scientific Soil Management”.   Apparently they do things that are good for the soil, though the “method” section of their website is a little too vague for me.  They also offer pictures of the results they’ve had with compost tea on a few different projects.  The one that was most interesting to me was the Rose F. Kennedy Greenway.  You can see it here.

Look at the boxwood comparison and you tell me why the compost tea didn’t do a darn thing.   Look at the grass comparison while you’re at it.

Throughout the Pennsylvania Horticulture Society’s website there are all kinds of opportunities to find out how to make and use compost tea, including courses at Meadowbrook farm.  Now that Elaine Ingham is at the Rodale Institute (Which is in Emmaus Pennsylvania) they have all kinds of classes on it there too.  Even Longwood Gardens is Getting into the act (scroll down and click on the compost tea link).  So what I want to know is, why have the Compost Tea Gods invaded my home state of Pennsylvania?  What makes the keystone state so attractive to people who want to promote snake oil?  I just don’t get it.  Is it the cheesesteaks?  Maybe the scrapple?

No, I’m pretty sure it’s the Rolling Rock….or maybe the Yuengling – America’s oldest brewery (their Black and Tan is one of the best beers in the US – second only to anything brewed by the Surly company).   Yeah, that’s gotta be it.

Gone but not forgotten…

Got to spend Friday in the field in northern Michigan visiting growers and seeing some neat stuff: Great fall color, some natural concolor x Fraser fir hybrids and some awesome root systems produced by root pruning.  Unfortunately, like the dog that ate the homework, my camera decided not to part with the images.  I am tracking down replacements and will post an update on Friday.</d

The wackiness continues

It seems like every year we end up talking about ‘weird’ weather; either it’s extreme heat, extreme cold, too much rain, not enough rain, and on and on.  Here in the upper Midwest and other parts of the central US, however, 2012 is clearly a year to remember.  Our winter was fairly unremarkable until we hit 8 days over 75 deg. in mid-March.  This pushed our growing degree days up at least 3 weeks and set the stage for widespread late-freeze damage in April, wiping out the state’s cherry, peach, and plum crops.  Summer turned out warm and dry, highlighted by record-setting heat in July.


Weekly average high temperatures from MSU Hort Farm weather station: 2012 versus average of 15 previous years.

Now that we’ve seen some relief from summer’s drought and heat, we’re experiencing one more weather-related phenomenon: stress flowering. At my place I had lilacs and azaleas start to flower in August. We have also had reports of crabapples flowering in the eastern part of the state. Trolling around the web, I ran across a photo of magnolias blooming this month in Kansas City.


Magnolia flowering in mid-September. Source: Kansas City Star

So, what’s going on? Severe heat and drought can cause plants to go into a state of eco-dormancy. Typically we define “true” dormancy as a state where plants won’t grow, even when environmental conditions are favorable. Eco-dormancy represent the flip-side; plants should be growing but can’t due to severe environmental stress. In some cases the stress can induce flowering, such as we’ve seen this year. We have also seen examples of trees that have re-flushed, sending our new leaves after shedding leaves during the peak of the drought.

Will any of this cause long-term problems for trees and shrubs? Probably not. Stress flowing tends to be sporadic so most flower buds on a tree or shrub are likely to be unaffected. Shoots that re-flush late in the summer may or may not be able to harden off before winter. If not, they will be subject to freeze injury just like shoots that flushed earlier the spring. The main concern for 2012 is the cumulative toll of our environmental extremes.

Why I Don’t Worry Too Much About Organic Fruits and Veggies

Let me tell you something you already know.  If you grow something in your own garden you’ll know exactly what poisons were or weren’t put on it, how much fertilizer was used, and furthermore it will taste better.

If you buy your apples from the guy down the street who you’ve known for 20 years you’ll be able to ask him what he used to grow the crop, why he used it, and you’ll have the satisfaction of supporting a local industry.  And yes, those apples will taste better than grocery store apples.

If you go to a farmers market you’ll be able to ask the people there exactly what they did to their crops, and why they did what they did.  And you’ll feel good about supporting the local economy.  And yes, the food will taste better than anything from the grocery store.

If you walk into a grocery store or Target, or Kmart or whatever and pull a fruit or vegetable off the shelf which has the USDA Organic Label on it and say to yourself “Hey, I’m doing something good for my family and the environment” then, in my opinion, you’re fooling yourself.

There, I said it.  I believe that, AS USDA ORGANIC CERTIFICATION NOW EXISTS, the USDA Certified Organic label does not provide a significant indicator that the fruit or veggies you’re buying provide a significant benefit in terms of human or environmental health.  Please note that I’m not saying anything different than our government does – what they say is: “Organic is a labeling term that indicates that the food or other agricultural product has been produced through approved methods that integrate cultural, biological, and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity.”

Notice that they never say that organic is superior to conventional production, simply that organic uses practices that “foster cycling of resources, promote ecological balance, and conserve biodiversity”.  Though many of you may not believe it, conventional growing uses many of these practices too –  producers know that if they don’t pay at least some attention to sustainability then they will lose money over time.

So why am I talking about this today?  Well, I’ve had a few requests to discuss that new meta-study that came out a few weeks ago which showed that organic food has the same nutritional value as food produced conventionally.  Big deal.  Plenty of other meta studies have shown essentially the same thing –the quality of organic is LARGELY the same as conventional with a few nutrients (often vitamin C) a little higher in organic and a few (often protein levels) being higher in conventional.  Anyway, to make a long story short, I don’t know why this study got more press – maybe they have better PR people at Stanford where the study was put together.

Look, the reason that one food has more nutrients than another has much more to do with the food itself than whether the food was grown organically or conventionally.  No matter how you treat a McIntosh apple, it will never have as much vitamin C as a Granny Smith apple.  Period.  Folic acid will always be greater in bananas than grapes.  Period.  If you’re worried about getting enough of a particular nutrient then eat foods high in that nutrient.  If you’re worried about a lot of nutrients then eat a varied diet.

Of course the study also says that synthetic pesticides are more likely to be on conventionally produced foods than organically produced foods.  OK, I’ll buy that.  Makes perfect sense….but tell me, how much organic pesticide is on organically produced foods?  And how does it affect you?  If a farmer uses spinosad, an insecticide used by organic growers, it can be present at low levels in food, as can other organic pesticides such as pyrethrum.  But since residues of these organic pesticides are rarely tested you have no idea how much is in there.

Look, if you want to avoid pesticides on your fruits and veggies altogether and can’t grow a garden or go to a farmer’s market, then you should avoid foods where pesticides need to be used. These are the only foods where you can count on growers, organic or conventional, avoiding pesticides (No farmer WANTS to use pesticides – they’re expensive!).  To find foods where pesticides are less likely to be used just go to that crazy dirty dozen list which the Environmental Working Group puts out (which I think is a bit ridiculous – but I’ll leave that alone for now since this post is getting long) and select fruits and veggies from the clean 15.

In terms of organic production being better for the environment, as long as organic growers can use copper to control diseases, I’m concerned about how long term applications of this copper will affect
620
soils on land devoted to organic production over the long term.  I’m also concerned about fertilizer runoff and leaching in organic production – same as in conventional production.  Nitrogen and phosphorus from manure can and do run off just the same as nitrogen and phosphorus from synthetic fertilizer.

In both conventional and organic systems, the impact that production has on the environment comes down to the responsibility that a given producer takes for doing the right thing and protecting the environment.  To say otherwise is just silly.  There is so much leeway in the USDA organic system that there is plenty of opportunity for a USDA organic producer to do things that will make their operation significantly worse for the environment than a conventional producer of the same crops.