Showing posts with label Treeshelters. Show all posts
Showing posts with label Treeshelters. Show all posts

Tuesday, February 4, 2014

It's best not to re-use tree tubes... but if you're determined to re-use them here are two ways to do it

This post is long overdue.  The single biggest mistake tree planters make when using tree tubes is that they remove them too soon.  As we have discussed, tree tubes are meant to fill three roles throughout the course of their life:  Establishment, support and bark protection.

In the establishment phase (1 to 3 years) the tree tubes protect seedlings from animals, reduce moisture stress (to enhance survival and growth) and shield seedlings from herbicide & mowers, to get seedlings off to a successful start.

At the point in time that the trees emerge from the tree tubes they will have a thinner stem relative to their height than trees planted without tree tubes (the difference being, of course, that trees planted without tree tubes often NEVER reach that height).  Tree tubes are DESIGNED to stay in place to support the trunk of the tree after it emerges from the tube, until the trunk thickens up.

Even when the trees are self-supporting they are still at risk for bark damage from deer (buck rub) and rodents.  Tree tubes are meant to be left in place for continued bark protection until the trees reach 3 inches in diameter at the base, at which time the tubes should be removed and disposed of.

HOWEVER.  Tree tubes are a significant investment for the hobbyist tree planter, and the idea of re-using tree tubes is very tempting... or even in some cases necessary.  Keep in mind that every time you remove a tree tube before it has completed its full job of getting the tree to 3 inch basal diameter you are taking the risk that something will happen - wind storm that breaks the stem, buck rub, gnawing rodents, mower damage - that will either set the tree back or even kill it.

The sooner after emergence you remove the tree tube the greatest the risk to the tree.  Tree planters have been successful using two different methods of re-using tree tubes. 

Good (highest risk but also highest number of uses for each tree tube):  Remove the tree tube shortly after the tree emerges, but tie the tree to the stake you were using to support the tree tube.  Preferably this would be a flexible stake like pvc.  I´m not a huge fan of this practice – I don´t like staking trees and of course it exposes the tree to rodent and deer damage.  But I have many customers doing this successfully and it does mean you can use the tubes two or three times.

 Better (less risk and affords opportunity to re-use the tree tube once):  After the tree emerges wait at least one full growing season and then remove the tube.  Especially when using pvc stakes the tree will gain a lot of caliper in that first growing season after emerging from the tube, and should be self supporting at that point.  The advantage is the ability to reuse the tube (and probably the stake if the tree can stand alone); the disadvantage again is exposing the bark to rodents and deer damage.

Best of all, of course is to keep the tree tubes on until the trees reach 3 inches in basal diameter.  At that stage you can remove the tree tube knowing it has completed the three functions for which it was designed, and safe in the knowledge that the tree is successfully established.

But if budgetary restrictions mean you have to re-use tree tubes in order to meet your planting goals, these guidelines will help you weight the risks of the various methods and will give you the best chance for success.

Thursday, September 26, 2013

New 'Micro-vented' tree tube hits the US market

A new tree tube with an intriguing combination of time-tested and innovative design features was recently introduced to the US market.

The Photosynth Tree Tube is in many ways a conventional tree tube, featuring a flared rim to prevent abrasion to the bark of emergent trees, twin-walled cylindrical construction for rigidity and durability, and releasable zip ties.

Venting has become standard for any high-performance tree tube.  Photosynth Tree Tubes have a 'micor-vented' design that has long been popular in Europe:

Rather than a relatively small number of larger vent holes punch sporadically in the walls of the tube, Photosynth Tree Tubes have thousands of small vent holes punched continuously from near the rim of the tube to approximately 16 inches from the ground.  This design result in more even gas exchange along the entire length of the tube.

The lower 16 inches of each Photosynth Tree Tube is solid for both herbicide spray and rodent protection.

Pricing of Photosynth Tree Tubes is highly competitive with other twin-walled tree tubes.  Tree tubes appear to be following - albeit at a slower pace - the pattern established with other new technologies, with the price decreasing as use of the technology becomes more widespread, competition among producers increases and production volumes increase.

It's a very exciting time in the tree tube industry.

Monday, August 26, 2013

Tree Tubes on American Chestnut Trees

Tree tubes are finally fulfilling their promise as an establishment aid for American chestnut seedlings.

If ever there was a perfect candidate tree for tree tubes it would seem to be the American chestnut tree.  Billions of majestic chestnut trees were wiped out by the fungal blight that swept through its range in the early- and mid-1900s.  It has been the focus of heroic re-establishment efforts on the part of organizations such as the American Chestnut Foundation and thousands of dedicated scientists and volunteers.  Every chestnut seed or seedling planted is rare & precious, and critical to the long-term success of re-establishment efforts.  But chestnuts are also extremely vulnerable to all of threats to successful regeneration that other species face, including deer browse, competing vegetation and periodic drought stress.

So given the value and importance of each and every chestnut seedling planted and the number of threats they face, one would think that using plastic tree tubes on American chestnuts would be a no-brainer... and indeed American chestnut enthusiasts were some of the first tree planters to recognize the potential benefits of tree tubes and give them a try.  Unfortunately, the performance of those early, unvented tree tubes on American chestnut seedlings left a great deal to be desired.

It turned out that chestnut seedlings grown in tree tubes were particularly vulnerable to winter injury and die back.  They also grew with elongated, spindly stems that often formed a spiraling or helix growth habit as they worked their way up the tree tube.  Word of these issues quickly spread in chestnut growing circles, and chestnut planters either switched to using 2ft or 3ft tree tubes (shorter tree tubes provided rodent protection but did not cause die back or spiraling growth) or stopped using tree tubes altogether.

Growers of Chinese chestnut trees, incidentally, experienced and reported these same problems, and many became disillusioned with tree tubes.

Recently, however, chestnut planters - both of American and Chinese chestnuts - have recognized the major advancements in tree tube design - most notably the addition of ventilation, better light transmission properties and larger tube diameter - and have given them another try.  This time around the results have been outstanding.

In this blog I have often discussed the evolution of tree tubes as the story of two eras:  Before Venting (BV) and After Venting (AV).  The entire history of tree tube use and effectiveness in North America can be divided into these two categories; the un-vented tree tubes that first came over from the UK and worked well in their moderate and very forgiving climate, and the vented tree tubes that work in the extreme climates - both cold and hot - found in the United States.  Nowhere is this dichotomy of BV versus AV illustrated more starkly and dramatically than with American and Chinese chestnut trees.

In coming weeks we will be posting accounts and photographs of tree tubes on American chestnut and Chinese chestnut trees.  Healthy, rapid growth and straight trunks have been the rule, as you see in dramatic fashion here:

(Click to enlarge)

This is a Chinese chestnut tree growing in Mississippi.  It was planted in July, 2012 as a 12 inch seedling.  It was protected with a 4ft tall tree tube, and was watered to help it survive the late season planting.  It didn't put on any additional growth for the remainder of the 2012 season.... in other words in entered the 2013 growing season 1 foot tall.  This photograph was taken in August, 2013.  The tree grew more than 8 feet in one growing season.

More important than the rapid rate of growth:

1) The tree - and many others like it in the same planting - is perfectly straight, with no sign of the spiraling growth seen in the early days of chestnut seedlings in un-vented tree tubes.

2)  The trunk diameter - while thin relative to it (amazing) height, as you'd expect with any tree tube grown seedling - is very robust.  This also due in large part to the adoption of flexible tree tube stakes such as 1/2" schedule 40 PVC, as was used here.

Note: That "tray" at the base of the tree is a revolutionary weed mat developed in Israel called the IrriPan Weed Mat.  It blocks weeds, captures rain water and funnels it to the tree, reflects light up to the tree, and recycles soil moisture.

Follow this blog for more upcoming posts chronicling the use of tree tubes on American and Chinese chestnut trees.

Thursday, March 14, 2013

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.

Wednesday, December 12, 2012

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.

Thursday, December 6, 2012

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.

Tuesday, December 4, 2012

Using tree tubes to establish native California oaks from acorns

We have been talking about various applications and uses of tree tubes.  One broad area where tree tubes have proven their mettle is in ecological restoration, more specifically the re-establishment of critical native species into environments that are no longer "native."  A great example of this is the use of tree tubes for California native oaks.

Tree tubes are being used coast to coast to help re-establish native trees whose numbers have dwindled due to disease (particularly in the case of the might American chestnut in the east) or to a combination of grazing, fire suppression, competition from exotic grasses & weeds, deer browse, rodent damage, and disease (in the case of California's native oaks).

As you can tell from that laundry list of threats, successful establishment of California oaks is not easy in 2012.  The mature oaks that line the golden hills of California got their start in a completely different world, before livestock grazing, before the spread of European annual grasses that have largely replaced less competitive native perennial grasses and forbes, and when fire - both lightening caused and as part of the vegetation management strategies of California's indigenous people - helped suppress competition giving oaks time and space to grow large enough to shade out competition.

Tree tubes to the rescue!  It is a truism that a) the more important it is that a particular tree get successfully established*, and b) the greater the threats to that tree's survival, c) the more more it makes sense to use tree tubes.

* Then again, in the same way that police officers should never draw their gun unless they intend to use it, people should never plant trees unless they intend for them to survive and thrive. 

All of this makes tree tubes the perfect tool for helping restore and re-establish California's beautiful native oaks.  And one of the best ways to plant California oaks is be direct seeding acorns and protecting them with tree tubes.

Blue oak acorns ready for planting
(Click to enlarge)

Planting acorns, chestnuts, black walnuts, and hickory nuts directly in the soil and protecting them with tree tubes is a practice that is really catching on.

In this case this blue oak (Quercus douglasii) acorns are being planted on former ranch land that is being converted to an oak preserve in the Sierra foothills near Springville, CA.

The acorns were gathered from local blue oak trees, to ensure that they are well suited to the climate and soil.  They were then soaked in a pail of water for 24 hours, and any "floaters" were discarded (floating after that period of time is a sure sign that weevils or other insects have burrowed into the acorn and have eaten all of the nutmeat that is needed to produce a new seedling).

Then two acorns are being planted in each planting hole, about 1 inch deep and loosely covered with soil.  Each set of 2 acorns is then being protected with 6 foot Tree Tubes for protection from deer, but more importantly from the cattle that will be grazing on this property for the next few years as part of a lease agreement.

The tree tubes will:

Protect the acorns and seedlings from rodents (except burrowing ground squirrels; other measures are being taken to protect from them)

Protect the seedlings from getting browsed or trampled by cattle (steel t-posts are being used for stakes, with a second, shorter stake being used on the opposite side to prevent cattle from rubbing against the tube and pivoting it around the stake.

Shield the seedlings from deer browse.

Greatly reduce moisture stress in an area that goes months without rain and where temp's often top 105 degrees.

Facilitate effective weed control, so annual grasses do not take the limited soil nutrients and moisture these oaks will need.
 
 
Tree tubes are proving to be an absolute must for the successful establishment of native California oaks.  Are tree tubes "natural?"  No, but then neither is the environment into which we are planting those native oaks - too many cattle, too much grass seed, and too little fire.



Wednesday, October 31, 2012

Driving unnecessary cost out of tree tubes

This blog is about the history, development and applications of tree tubes.  But it is also chronicles the evolution of the companies that are trying - as has happened with so many technologies - to drive down the cost of using tree tubes and make them accessible to the largest number of users.

In the previous post I discussed one company's obsession with keeping the final, delivered cost of tree tubes as low as possible to make them affordable for more tree planters.

Here is a great post from another company, Tree Protection Supply, which shares this philosophy, using creative, custom packaging and aggressive shopping of freight services to keep their prices on tree tubes  low.

So much of the price of the things we buy has nothing to do with the cost of raw materials and manufacturing, and everything to do with secondary costs such as transport, overhead, packaging, marketing - not to mention profit margin.

In the case of tree tubes many suppliers have extremely high secondary costs and profit margins.  It is therefore possible for companies that focus on keeping secondary costs to an absolute minimum to sell a BETTER PRODUCT at a LOWER PRICE than tree tube companies selling a product of lesser quality.

Hmmm ... Better product at a lower price.  That sounds to me like the way a technology goes from a niche product to widespread acceptance.  And tree tubes are definitely following that trajectory!

Monday, October 22, 2012

Tree Tubes for Planting Landscape Trees

Dr. Doug McCreary is the guru of oak regeneration in California.  Some years ago he spent his sabbatical in England, learning about English practices for growing, planting and protecting oaks.

One of his reports is here.

Bottom line:  We in the USA can learn an awful lot about successful and cost effective establishment of landscape and roadside trees.

Corollary:  Seedling trees in tree tubes 1) cost many times less, 2) survive at a higher rate, 3) grow faster and 4) live longer than what we currently do (planting large potted or B&B trees that cost hundreds of dollars, have deformed root systems, suffer years of transplant shock, grow slowly, and succumb to disease, insects and root strangulation).

Some key points from Dr. McCreary's report from the UK:

"When driving around the English countryside, one notices that treeshelters (tree tubes) are everywhere... Some estimates are that between three and five million treeshelters are sold annually in this country that is half the size of California."

"Even though the sight of treeshelter forests is not the most aesthetically pleasing - and I suspect some environmental groups might prefer to see them banned from the planet forever - they seem incredibly effective for reforestation in England (emphasis mine)."

We'll be looking at this issue of the aesthetics of tree tubes in a post later this week.  Not surprisingly I find a field with tree tubes in it for a few years to successfully establish trees that will live another 100 years much more aesthetically pleasing than a failed planting.

"While stuck in traffic, I tried to determine how many (tree) shelters in a roadside planting had surviving plants inside... a 'windshield assessment' indicated that over 90% of the trees were growing out of the tops of the tubes.  This is consistent with a large-scale survey here several years ago of over 4,000 (tree) shelters on 192 sites where 89% contained a living tree."

"Clearly the success rate seems far higher than for roadside plantings along California highways.  The fact that England has much more summer rainfall probably contributes greatly to excellent seedling growth and survival, but I suspect that (tree) shelters here are more carefully and properly installed and maintained... Whatever the English do, it works, and we have much to learn from their many years of experience with these devices (tree tubes) that, so far, seem particularly useful for regenerating oaks in California as well (emphasis mine)."


Wednesday, October 10, 2012

Extending 4ft Tree Tubes

Expanding on our recent theme of choosing the best tree tube height, here's a great post from Tree Protection Supply on their new Tree Tube Extender product.

4ft tubes provide enough deer browse protection 75% of the time.
5ft tubes provide enough deer browse protection 90% of the time.

A perfectly legitimate strategy is to start with 4ft tree tubes and then, if deer start browsing trees as they emerge from the tubes, use a 2ft tree tube extender to get another 2ft of protection - not to mention another year of very accelerated growth.

Chances are the deer will only browse certain species as they emerge from the tubes, or will only browse in certain places (such as next to the field where they bed down, along a creek, etc.) so you might only need tube extenders for a small percentage of your 4ft tree tubes.

PVC tree tube stakes make this easy, because you can just snap a 2ft extension to the the top of the 4ft stake, and you're good to go.

It's so cool to see so many tree tube companies getting on board with the vented tree tube plus PVC stake combination - and more importantly to see so many landowners reaping the benefits!

Tuesday, October 2, 2012

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

 imageThe 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.

Monday, October 1, 2012

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).

Tuesday, September 11, 2012

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!




Tuesday, September 4, 2012

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!