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  More recently white oak has largely been replaced by bamboo as a cost-saving alternative.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).