Tree Tubes - defying predictions

People who have never tried tree tubes nearly always predict dire results, the most common of which is that the seedlings will "burn up" or "cook" inside the tree tubes.

Here's an interesting tree tube post about how this near-universal prediction has been proved wrong time and again.

Why do we need tree tubes?

Why do we need tree tubes in order to successfully establish seedling trees?  After all, trees managed to grow before tree tubes existed.  Why do we need tree tubes now?

There are two answers to that question.

The first is that a tree planting project is different than a naturally regenerated forest.  A naturally regenerated forest is the result of hundreds of years, billions of seeds, and a huge amount of random chance.  The odds that any one tree seed will someday become a mature tree are minute.  The accumulation of huge spans of time and huge numbers of seeds ultimately result in a forest... sometimes.  Nature has plenty of failed attempts at forest regeneration (we call these failures "prairies"). 

It takes an enormous amount of work - not to mention money - to plant trees in order to create a new forest.  And since the tree planting can't sow billions of tree seeds and doesn't have hundreds of years to wait, something has to be done to take the element of random chance out of the equation.  There are lots of ways to do this, to tip the scales of chance more in favor of success - planting species most likely to thrive in local growing conditions, properly planting high quality stock, and aggressively suppressing vegetative competition.

But the single most powerful tool to turn the odds in favor of the tree planter over random chance, if the tree tube (or treeshelter as it is known in the UK and among hardwood silviculturists in the USA).

The second reason we need tree tubes today is illustrated beautifully in this chronology given on this web page of the Oklahoma Department of Wildlife Conservation.

1900 - market and subsistence hunting virtually eliminate deer in Oklahoma

1917 - statewide deer population estimated at 500 

1944 - 379 deer harvested by hunters

2005 - 101,111 deer harvested, 40% of them does (which means wildlife managers are trying very hard to reduce the size of the herd)

This numbers are nearly the same in every state east of the Rockies.  Deer nearly wiped out by 1900, followed by reduced or banned hunting for a period of time, combined with heroic conservation efforts to restore whitetail deer, combined with changes in the landscape (creation of a patchwork with exponentially more forest edge, the preferred habitat of deer) and reduced predator populations, leading to huge deer harvests that still can't keep pace with the rate of reproduction.

Many of the natural forests we have can very likely trace their origins to that 1900 time period when deer numbers were at an all time low.

We are now trying to plant trees when the deer population is at an all time high.

There are now places in the USA where natural hardwood regeneration is seriously threatened, where there are very few young hardwood trees.  The deer simply eat them faster than they can grow.

So random chance is not an option any more.

There are other ways to protect trees from deer browse, but none as cost effective as tree tubes.

Never a bad time to apply Tree Tubes

One common misconception about Tree Tubes is that they can only be applied to newly planted seedlings, right at the time of planting.

Fact is, there's never a bad time to apply tree tubes, as this excellent You Tube video from Tree Protection Supply demonstrates.

There are so many small trees out there - both planted in previous seasons and naturally regenerated "volunteers" - that could benefit greatly from tree tubes.

Rule of thumb:  As long as you have a living root system and a tree tube you can grow a great tree.

Those oak or black walnut or crab apple seedlings you planted three years ago that the deer have kept browsed to ankle height?  Prune them to a single stem and put a tree tube on them.

Those "volunteer" oaks you find when hunting, after bush hogging or just when out for a walk?  Carry some flagging tape with you to mark them, and then go back out with pruning shears and tree tubes in hand.

In both cases you have a big, strong root system that just needs the protection of a tree tube in order to express itself.  Landowners often can't believe how fast these trees grow in the year after tubing them.

Rejuvenating struggling seedlings is one of the most rewarding uses of tree tubes.

Absolutely astounding growth of oaks in tree tubes

This is unbelievable even to me - and I've worked with tree tubes for 23 years. 

This is a hybrid oak - overcup oak x white oak.  It was planted in March, 2011 as an 18 inch seedling.

(Click to enlarge)

 

This photo was taken yesterday, against a darkening Mississippi sky.  That tree is now 11 feet 8 inches tall.  (The tree tube is 4ft tall and the photograph is taken from ground level looking up.)

Let me be a little more clear, because it really is hard to wrap your brain around this:  In just two growing seasons this tree has grown 10 feet 3 inches since being planted as a seedling.

When I take a step back I shouldn't be surprised.  In fact these are the kind of results that I believe will become commonplace in the next decade.  It is the result of several factors:

1) Tree seedling planting stock is much, much better than ever.  Nurseries are selecting seed from superior trees, and are producing healthy, vigorous planting stock (especially stock growing in root-pruning pots) that is ready to "hit the ground running" with little or no transplant shock.

2) Trees - even oak trees - actually, especially oak trees - are inherently capable of remarkable growth.  Reaching that growth potential is simply a matter of removing the obstacles - the stresses - that prevent it from growing as fast as it might.  Those stresses include weed competition, drought, lack of nutrients, and of course animal browse.

3) Tree Tubes make it easy for growers to eliminate most if not all of those stresses:

> They shield tree seedlings from deer browse

> They make it easy to locate tree seedlings amidst the grass and brush, and protect them from weed control treatments that eliminate vegetative competition (thus making more moisture, nutrients and light available to the seedling)

> The shelter tree seedlings from drying winds, and capture and condense transpired moisture, returning it to the soil to be re-absorbed by the seedling.

In subsequent posts we'll be looking at how to achieve peak growth performance like this!

Tree Tube Myths: Does this look like a spindly stem to you?

One of the "knocks" against tree tubes over the years is that, while they unarguably accelerate height growth, they produce trees with thin spindly stems.  To this criticism I have two responses:

1) A six foot tree with a thin stem and a sturdy treeshelter in place to support it until the stem thickens up enough to support itself is a whole lot better than the alternative:  A seedling without a tube that is continually browse by deer to the point where it dies or is stunted at knee height for years.

2) Today's vented tree tubes and flexible PVC stakes have combine to make a myth out of the "spindly stem" critique of tree tubes.  Thin stems are a thing of the distant past.  Take a look:

(Click to enlarge)

This is the trunk of a hybrid oak from Mossy Oak Nativ Nurseries planted in a 4ft Tubex Combitube Plus Tree Tube.  Here's the chronology:

* Planted as 18 inch seedling in March, 2011

* Photo taken on August 2, 2012 - less than two complete growing seasons later!

The tree is now well over 10ft tall.  But most exciting to me is the large caliper of the trunk immediately above the tree tube.  You can see that with today's vented tree tubes and flexible PVC stakes it's not just a matter of producing the same amount of biomass growth and just "stretching" it in height, as might have been the case with early tree tubes.  No, this tree is putting on a HUGE amount of total biomass (especially when you consider that stem diameter is the best "window" into what's going on with root growth below ground).

As with so many discussions of tree tubes it comes down to B.V. (Before Venting) and A.V. (After Venting). Before venting trees were definitely better off with tree tubes than without, but exhibited some "side effects" like thin stems.  After venting tree planters are realizing the full potential of tree tubes and seeing astounding growth, both in terms of height but - more importantly - in terms of stem diameter.

Think of it this way, using a computer analogy:  Unvented, small diameter tubes of the past = MS-DOS.  Today's vented, large diameter tubes combined with flexible PVC stakes = Windows XP.

Tree Tubes for healthy, low-cost & long lived landscape trees

 The whole reason I started promoting tree tubes back in 1989 as a newly-minted Urban Forester (University of Minnesota) was because I saw them as a way to successfully plant in urban landscapes tree species that are not sold as large potted or B&B trees by the commercial nursery industry, but instead are available only as seedlings.  I was concerned primarily with oaks, which are not widely sold in the nursery trade due to the ridiculous misconception that they are slow growing, but also with other native species that are drastically under planted.

My thinking was:

1) Many tree species are only available as seedlings (especially deeply tap-rooted species that don't lend themselves to current nursery production practices)

2) Plant a seedling unprotected in the landscape and it will get eaten or run over with a lawn mower

3) Tree tubes + seedling trees = a low-cost, highly effective way to plant seedling trees in the landscape

Twenty-three years later my conviction that this is the best way to plant landscape trees is even stronger.  That's because I have learned,

1) Most potted or B&B trees sold in the commercial landscape industry have deformed, mangled and/or maimed root systems that impede growth, cause long term health problems, and dramatically shorten the lifespan of landscape trees.

2) The smaller the tree you plant, the less root disruption/deformation there is, the faster it will growth, the healthier it will be, and the longer it will live.

Landscape tree tube naysayers have often made the argument that tree tubes in the landscape, and especially when used for street trees, would likely become targets of vandalism.  To which I say:

1) In the increasing number of cases where tree tubes have been used to establish street, park and landscape trees the amount of vandalism has been nil.

2) Trees do get vandalized.  Would you rather have a vandal wreck a $300 B&B tree or a $10 tree tube and seedling combo?

I am getting more and more emails and phone calls from folks thinking along the exact same lines.  According to one online poll of tree tube buyers 13% of them are using the tree tubes to plant landscape trees.  Back when I started that number was a lot closer to zero. 

I received this email from a customer last week:

Within the last few weeks, the Emerald Ash Borer made its way into Massachusetts.  In central Massachusetts, the USDA has been trying to eliminate a threat from the Asian Long Horned Beetle.  I think because of pests like these there will be increasing emphasis on ways we can increase biodiversity in the forest.  The tree shelters seem like they should greatly improve results...  In these difficult economic times, the town does not have the funds to remove all the dead trees, never mind plant new ones.  I wondered if planting seedlings and using tree shelters might be an economical way to get something new planted in the springtime.

To which I say:  Amen!
 
 And here is an awesome post with a first hand case study of using tree tubes to plant landscape trees - and it involves planting my favorite tree, bur oak - a FAST GROWING, rugged, gorgeous trees that is laughably under planted in the landscape.

Tree Tube Innovations, Part 2: PVC Stakes

I find it interesting that the 2 major innovations in Tree Tube design and performance in the last 20 years have both originated with customers, and not the companies that make and sell tree tubes.

I also find it embarrassing, since I am one of the few guys who has been selling tree tubes from the very beginning.

The first major innovation was ventilated the tubes.  I covered venting in detail in a recent post.  I consider the advent of vented tree tubes to be so important that in my mind I divide tree tube history into two distinct eras:  Before Venting (BV) and After Venting (AV).

The second and more recent innovation is the use of PVC Tree Tube Stakes.  Trust me, as someone who has sold tree tubes for 23 years, the stakes needed to support the tubes have been the biggest headache and source of frustration.

Tree tube suppliers didn't come up with the idea of venting the tubes because they were working under a false assumption: That the reason tree tubes accelerated growth was because they functioned as an almost hermetically sealed growth chamber.  It took customers drilling holes in their tubes and reporting their great results to make us realize that tree tubes accelerated tree growth despite being hermetically sealed environments, and that they accelerated growth even more - and without the negative "side effects" common to unvented grow tubes - when holes were punched in them allowing a freer exchange of carbon dioxide.

Similarly, tree tube makers didn't develop the idea of using PVC tree tube stakes because of another false assumption, namely the assumption that tree tubes and stakes are two separate product lines rather than two components of the same product system.

I guess another false assumption is that when we think of "stake" we naturally think of wood.

A third false assumption (gosh we tree tube peddlers sure have made a lot of them!) was the idea of tree tubes as a "plant and walk away" system for tree establishment (which in terms of feasibility is right up there with cold fusion and perpetual motion machines) - the idea being that the tree tube would photodegrade and the stake would biodegrade over time.

This "hat trick" of false assumptions meant that white oak and other decay resistant hardwood lumber became the workhorse tree tube stakes for two decades.  More recently white oak has largely been replaced by bamboo as a cost-saving alternative.

It's safe to say once again that tree tubes succeeded despite the use of wood, bamboo or any of the other materials used as tree tube stakes.  The basic problem with wood and bamboo stakes - especially bamboo - is that they break, split and degrade too soon.  There's any old joke about ranchers being full time fence repairmen who keep livestock as a hobby.  Well, with wood and bamboo stakes tree tube users were essentially stake replacers with a tree planting hobby.  That's how much time was spent in replacing broken and rotten stakes.  (A customer told me just this morning that he has never made a trip to check on his trees without having to replace old wood or bamboo tree tube stakes.)

But the problem with wood and bamboo stakes goes far beyond breakage and biodegradation.  The deeper problem is that they don't complement the tree tubes.  They don't contribute to the performance of the tree tubes.

One side effect of growing trees in tree tubes - even vented tree tubes - is that the trees tend to have thin stems relative to their heights.  Tree tubes channel growth upward, and the trees are isolated from the environmental feedback - especially the swaying and shaking effects of the wind - that trigger growth responses that allocate more growth resources into thickening and tapering the trunks and developing bigger root systems. 

About 5 years ago I started hearing about customers using 1/2" pvc conduit as tree tube stakes.  I am embarrassed to say that - as I was with grower reports of the benefits of venting the tree tubes - I was skeptical.

The solution was in the hardware store the whole time!

1/2" pvc conduit makes the best tree tube stake, swaying

in the wind but never breaking.

And once again, I was wrong.  Way wrong.

We already know that we have to go back at some point - 3, 5 or 7 years down the road - and remove the tree tubes from the successfully established trees.  Therefore we know that we can retrieve (and then reuse) a non-biodegradable stake at that point... so biodegradability is not a critical factor for a tree tube stake.  

It's also easy to understand - as my customer did this morning - that PVC tree tube stakes won't break, and will save dozens of extra trips to the field to replace broken or rotten stakes.

However, the most important thing about PVC tree tubes stakes is:  They make tree tubes perform even better (rather than being a necessary evil tree tubes - and their users - must put up with and overcome).

They make tree tubes better by providing the environmental feedback - swaying and shaking in the wind - the seedlings in tree tubes don't get with rigid stakes.  Again it is that swaying motion that triggers hormonal responses which in turn "tell" the tree to channel more growth energy into stem thickness and taper as well as root develop (so-called secondary growth responses).

Take a look at the photo above.  This photo was taken late in the second growing season of a hybrid oak grown in a vented tree tube supported by a PVC stake.  This kind of caliper growth was unheard of with rigid wood or bamboo stakes.

This kind of caliper growth means that now when trees emerge from tree tubes they don't - as they had to in the past with rigid stakes - slow their height growth while reallocating growth energy to stem caliper and taper.  Now they get to the top of the tube... and keep right on going!

So once again, to my customers:  You were right, I was wrong.  Tree tubes & stakes are not two separate products.  They are component parts of the same product, and need to work together symbiotically to achieve the best results. 

PVC tree tube stakes solve all of the problems of wood stakes, completely negate one side effect of tree tube use.  Best of all, they do so for less than the delivered cost of bamboo stakes, and WAY less than the delivered cost of white oak stakes (and, by the way, much MUCH less than fiberglass stakes).

Tree Tube Chronology: B.V. and A.V.

Outstanding stem caliper growth in 2nd year oak planted as 

an 18 inch seedling in a 4ft Tubex Combitube Plus Tree Tube.

 

 I divide the history of Tree Tubes in the USA into two distinct eras:  Before Venting (B.V.) and After Venting (A.V.).  Venting - the seemingly simple act of punching holes in the solid walls of the tree tubes - is the single most important advancement in the development of tree tubes.

 

By 1989 treeshelters were widely used and accepted in the UK.  The largest and best maker of treeshelters was Tubex, Ltd.  Tubex Treeshelters were introduced to the USA in 1989 by a small company based in St. Paul, Minnesota.

At that time all tree tubes were unvented - solid translucent corrugated tubes.  It was thought at the time that the rapid growth of tree seedlings inside the tree tubes was due to the creation of a "greenhouse effect," and the goal was to create an air-tight growth chamber.

I was there at the beginning.  I was the first employee - fresh out of forestry school - of that first company that introduced Tubex Treeshelters to the USA.  By and large the results in the field with those unvented tubes were good - excellent survival rates, rapid height growth, and of course "not getting eaten by deer" generally beats the heck out of "getting eaten by deer."

But we also started to get some troubling reports of problems from the field - and not coincidentally those problems were more serious the farther you got away from areas with climates most similar to the UK.  Those unvented tubes performed well in the Chesapeake Watershed region, and in coastal California and the Pacific Northwest.

However, get the farther north or south you went, the more frequent and serious the complaints.  These complaints fell into three categories:

1) Winter injury.  In northern climates seedlings in tree tubes simply didn't harden off properly for winter, and often suffered die back due to cold weather.

2) Spindly stems.  Seedlings in tree tubes exhibited rapid height growth, but the trees had very thin stems relative to the height of the trees.

3) Fungal problems, notably in the south, and probably due to excess moisture in the tree tubes.

 

So by this point - and we're talking about the mid 1990s - the potential of tree tubes to increase survival, shield valuable seedlings from deer browse and accelerate height growth was clear to all.  However, it was equally clear that in many cases, and especially the more extreme the climate, the upside of using tree tubes was largely counteracted by the side effects: winter injury, thin stemmed growth, and fungal diseases.

 

Enter some good ol' Yankee ingenuity!  Every software package ever introduced has had 'bugs' that needed to be ironed out with subsequent updates.  The first effort at 'de-bugging' tree tubes was a partial recognition that air flow in the tubes can be good; growers in northern climates were advised to elevate their tree tubes in early autumn to allow the trees inside the harden off for winter, and then lower the tubes back to the ground after the first hard frost.

 

This advice worked as far as it went; elevating the tubes did greatly reduce the incidence of winter injury.  It also exposed the base of each seedling to rodent damage at a time of year when rodents are hungrily feeding in preparation for winter.

 

Then some enterprising landowners applied something that we tree tube peddlers sorely lacked:  Common sense.

 

Landowners started drilling holes in the tubes, and then calling to tell us how well their trees were growing.  And we tree tube peddlers did what most 'experts' do:  We ignored them.  In was only when research done in far away France confirmed - and scientifically explained (more about this below) - the benefits of venting that we finally took notice... and slapped ourselves on the forehead with a loud "d'oh!"

The performance of vented versus unvented tree tubes is night and day.  Venting didn't just solve the side effects of those early tubes.  It unleashed the full potential of tree tubes to massively increase total biomass growth.

The French researchers figured out that in solid tubes carbon dioxide often becomes a limiting factor - the seedling uses all of the CO2 in the tube then grows very little until the CO2 level recharges. In vented tubes the CO2 level is constantly recharged, and never is a limiting factor.

In addition properly vented tubes (such as the Tubex Combitube Plus) allow dappled sunlight to strike the leaves, and allow a puff of air to gently shake the leaves.  In both cases this triggers growth responses in the tree similar to if the tree was growing in full sun in an open field (namely thicker stem caliper growth and better root development) - except that the seedling still enjoys complete deer browse protection and a massive reduction in moisture stress a compared to its un-tubed comrades.

 

Even though unvented tubes performed well in areas with mild or maritime climates, it is important to understand that there is no climate in which an unvented tube outperforms a vented tube.

So you can see why I divide the history of tree tubes in American into B.V. and A.V:

Before Venting:

Complete deer browse protection

Increased survival

Rapid height growth

* Winter injury in cold climates

* Thin-stemmed growth in all climates

* Fungal diseases in hot/humid climates

After Venting:

Complete deer browse protection

Increased survival

Increased total biomass growth - height, stem caliper and roots

No more winter injury

No more fungal disease issue

 

In summary, tree tubes as they were developed in the UK were a great idea, but it took some French research and bunch of landowners with cordless drills and common sense, to unleash their full potential!

Let's start at the very beginning...

... a very good place to start!

And let this be the official beginning of a campaign for Mr. Graham Tuley to be awarded a Nobel Prize.  I'm serious.  Tree tubes are the single most important invention in tree establishment, and given the monumental importance of successful tree establishment and reforestation it's not a stretch to say that tree protectors are one of the most important inventions of the last century.  The iPod plays music.  Tree tubes heal the planet.

Treeshelters - as they were known in their early days - were developed by Mr. Tuley in 1979.  Tuley was a forester with the UK Forestry Commission.

Frustrated by continued failures in hardwood establishment - primarily English oak (or, as the British call it, common oak) and sessile oak - due to increasing levels of deer and rabbit browse, Tuley struck upon the idea of forming translucent plastic tubes around each seedling.  The idea was essentially to provide "safe passage" past the worst of the deer browse, while still giving the seedlings plenty of sunlight for growth.

The potential benefits in terms of animal browse were immediately obvious.  The wire or plastic mesh guards in use at the time had many failings; they were cumbersome to apply, and shoots often grew through the mesh to either get browsed by deer or later become girdled by the mesh itself.

Known in those early years as Tuley Tubes these solid translucent plastic tubes would clearly provide complete protection from animal browse until the seedling grew out the top.  The question was, how well would the trees grow inside the tubes?  The answer turned out to be:  Really, really well.  In Tuley's own words:

"(Tree) Shelters are 1.2 m tall plastic tubes which protect trees from animal damage and improve growth by creating a ‘greenhouse effect’ round each tree. After 3 years the mean height growth of sessile oak transplants in shelters was 142 cm compared with 45 cm in a mesh guard and 27 cm for unprotected trees and the average stem volume was 118, 37 and 19 cm³ respectively."

I think it's safe to say that Mr. Tuley was on to something big.

And after three decades of refinement - in design, protection methods, and guidelines for proper use - tree tubes have become and indispensable tool for successful reforestation worldwide.

There are so many heroes behind the treeshelter story.  And I'll keep telling them. Stay tuned!