Tag: woody

Superstorm Sandy aftermath: A modest proposal

Initial estimates from insurers indicate that Superstorm Sandy may be the second costliest storm in US history.  A large portion of the damage attributable to Sandy and several of the deaths associated with the storm were due to falling trees.   In many cases the winds were severe enough to topple healthy trees, but I’m sure many GP blog readers share my frustration in looking at storm-related tree damage photos and seeing obvious defects that a professional arborist would have readily spotted.

This brings me to a modest proposal: I propose insurance companies provide discounts for homeowners to have a hazard evaluation of trees on their property.  I did a quick search on the major insurance companies and they currently offer homeowners discounts of up to 15% for, among other things:

Smoke alarms

Burglar alarms

Fire extinguishers

            Security systems

Roofing materials

Sprinkler systems

The rational is self-evident; the cost of the discounts is more than off-set by damage and subsequent claims that are prevented.  How much of a discount should homeowners get for a hazard assessment?  I dunno, but I’m sure there are actuaries somewhere that could figure out cost-benefit breakdown of identifying hazards and removing them on a calm, clear day versus waiting until they come down in a major storm and destroy a car or a house or worse.

Tree research continued

Not to be outdone by Bert’s recent postings, I thought I’d show you what’s going on with MY tree research in Washington State.

As you might remember, we installed 40 1-gallon mugo pines and 40 B&B Japanese maples at the end of December 2011.  Here’s a photo of the site in April of this year:

I’ve been collecting data on above-ground growth during this year, but have had an unexpected twist to my research, as shown here:

That’s a pine tree.

Yes, we have moles…BIG moles apparently…in Puyallup.  There’s not much I can do besides move the soil away, but obviously the pine trees are not going to be happy with this additional treatment.  The maples are tall enough where it’s not going to be much of an issue.

Note to self: next time install guard Dachshunds next to pine trees. (Thanks to the Fremont Tribune for this great photo!)

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…”

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.

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.

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Why it’s important to prune tree roots before planting

This week I discovered that one of our center’s landscape trees is ready to bite the dust. I was sad – but also happy.  It’s a wonderful teaching moment and if the tree has to give up its life to save others, I guess that’s okay.

As the video will show you, this Japanese maple was planted some years ago with a root circling the trunk.  As both the trunk and root have developed in girth, we’ve reached a point where the trunk is constricted and the weight of the tree is splitting this V-shaped specimen down the middle just like a turkey wishbone.  We’ll just have to see how long it takes.

 

Bottom line: even though it takes a little more time to correct a flawed woody root system, it’s well worth the effort.

The good, the bad, and the ugly. A reply.

Ginny Stibolt of the Florida Native Plant Society recently posted Native Plant Issues: The good, the bad and the ugly, featuring me as the ugly.  I posted a reply on her post, which I include here.  To keep things in context, I encourage you to read her post first.

Enjoy your weekend!

Hi Ginny:

Some comments and a few points of clarification.

On the first item, as a Federal agency the USDA is bound by the Executive Order on Invasive Species which defines natives as species that occur in an ecosystem “other than as a result of an introduction”.  I suspect they tried to simplify the language for the National Planting day release when they substituted ‘naturally occurring’.

On the Arbor Day Foundation, I am fairly certain they use contract nurseries in various locations for their tree sales.  In any event, they have plenty of trained foresters on their staff that understand the importance of provenance and they would not send trees from northern seed sources to Florida or vice versa.  But I certainly can’t fault the idea of supporting the Arbor Foundation, declining their trees, and buying trees from a local nursery.

On the Google + Hangout discussion no one was ‘booted off’.  These were straight and simple technical issues.  If people watch the Youtube video, the audio sounds like Neil Armstrong on the moon.  This is a new technology for most of us and we are dealing with some growing pains.  I would have much preferred even numbers on each side.  Having an imbalanced debate can work against the majority, too.  As Wilt Chamberlain famously observed, “Nobody roots for Goliath.”  That said, we did have a lively and cordial debate and I hope people will bear with the grainy images and tinny audio and take a look.


Kentucky coffeetree

I haven’t watched the video but I don’t think I said there were no natives that could be used as street trees here in Michigan.  If I did, I misspoke.  That might be true for Linda in the Northwest – if you look at the native tree list for King county you’d be hard pressed to find anything that could be recommended in good conscience as a street tree.  We have a few more options here in Michigan.  If we were looking for a street tree for Lansing or Detroit the list could include hackberry, honeylocust, Kentucky coffeetree, tulip poplar, swamp white oak, and red maple.  But even this list makes urban foresters cringe because they think red maples are already over-planted, tulip poplar is weak-wooded, and hackberry is difficult to transplant.  With regards to Mary Wilson’s comments, there is a distinction between street trees and landscape trees.  Landscape trees could be anywhere on a residential or commercial landscape where they could receive irrigation or other care so there is broader list, in contrast to street trees found on street sides in tree lawns or tree pits.  Street trees are subject to the ‘worst of the worst’ in terms of environmental conditions; minimal rooting volume, compacted soils, road salt, and reflected heat load; but they provided the ‘biggest bang’ in ecosystem services, especially cooling buildings and sidewalks.


Swamp white oak

This has been an interesting discussion and clearly I have touched a nerve.  I have to confess I have never been vilified so much in my life, which has been a little discomforting but also strangely flattering.  When I met with Jeff and Linda earlier this week Jeff commented, “Wow, I’ve never been able to sit across the table from the devil incarnate before!”  Fortunately, I work in academia where we spend most of our days telling one another how stupid the other is.  People that seek to avoid criticism generally don’t do well in this line of work.  Peer review forces us to critically examine our statements and sharpen our arguments.  I was pleased and gratified to see some of the changes proposed for FNPS website and literature – why leave ‘low hanging fruit’ around for critics?  While I didn’t appreciate some the comments made about me, if I’ve caused this group and others to strengthen their arguments and re-examine some of their assertions regarding natives, then the slings and arrows I’ve taken these past couple weeks haven’t been in vain.

Last minute advice about Christmas trees and other fun stuff

The next podcast is up and running for your listening pleasure.  I’ve got an interview with Dr. Gary Chastagner, WSU’s Christmas tree expert.  He’ll tell you about his latest research and share some tips for keeping your tree happy and your carpet needle-free.

Here are some photos from Gary’s “dungeon” where he’s been comparing needle retention with some new promising conifer species from other parts of the world:


In the dungeon with Gary Chastagner


What dungeon would be complete without a rack or two?


I know which one I’d choose…

If you are really hard core, here’s a link to some of Dr. Chastagner’s research.  Just look for the Christmas tree heading and click on it.

Opening up a can of roots (or worms as the case may be)

Blog reader Alan Haigh asked if we could start a discussion about tree planting recommendations.  He sent along these guidelines from the Colorado State Master Gardener Program.

While I’m glad to see that the consensus now seems to be that burlap, wire, twine etc. do not belong in the planting hole, there’s still plenty of issues to contest.  Here are just a few that I found on my first read:

1)  Not mulching over the root ball;

2)  Assuming that all B&B trees are “field grown,” which I *know* is incorrect for so very, very many B&B trees;

3)  Not including the root-washing technique for B&B, which is not only research-based but is actively promoted through the International Society for Arboriculture’s workshops (see this posting for instance).  This is the only way to find and correct circling and girdling woody roots, and the easiest way to find the root crown for planting at grade.


Without root washing you’d have to dig through 10″ of clay to find the root crown (the duct tape marks the top of the clay root ball prior to washing)

I’ve written about this topic before.  And many people argue that it would “take too much time” and “be too expensive” to root wash specimens.  But when you read this publication, note that it takes 13 pages to describe how to plant containerized and B&B trees.

It takes 1 page to describe how to plant a bare root tree.